com.sjdf.platform.xss.StringUtils.java Source code

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Here is the source code for com.sjdf.platform.xss.StringUtils.java

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package com.sjdf.platform.xss;

import com.sjdf.platform.CommonPlatformConstant;

import java.io.UnsupportedEncodingException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.*;
import java.util.regex.Pattern;

/**
 * Create at 20131111 ?6:04:27
 *
 * @category author KETQI
 */
public abstract class StringUtils {
    public static final String[] EMPTY_STRING_ARRAY = new String[0];
    /**
     * The empty String {@code ""}.
     *
     * @since 2.0
     */
    public static final String EMPTY = "";

    /**
     * Represents a failed index search.
     *
     * @since 2.1
     */
    public static final int INDEX_NOT_FOUND = -1;

    /**
     * <p>
     * The maximum size to which the padding constant(s) can expand.
     * </p>
     */
    private static final int PAD_LIMIT = 8192;

    /**
     * A regex pattern for recognizing blocks of whitespace characters.
     */
    private static final Pattern WHITESPACE_BLOCK = Pattern.compile("\\s+");

    /**
     * <p>
     * {@code StringUtils} instances should NOT be constructed in standard
     * programming. Instead, the class should be used as
     * {@code StringUtils.trim(" foo ");}.
     * </p>
     * <p/>
     * <p>
     * This constructor is public to permit tools that require a JavaBean
     * instance to operate.
     * </p>
     */
    public StringUtils() {
        super();
    }

    /**
     * <p>
     * Checks if a CharSequence is empty ("") or null.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isEmpty(null)      = true
     * StringUtils.isEmpty("")        = true
     * StringUtils.isEmpty(" ")       = false
     * StringUtils.isEmpty("bob")     = false
     * StringUtils.isEmpty("  bob  ") = false
     * </pre>
     * <p/>
     * <p>
     * NOTE: This method changed in Lang version 2.0. It no longer trims the
     * CharSequence. That functionality is available in isBlank().
     * </p>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if the CharSequence is empty or null
     * @since 3.0 Changed signature from isEmpty(String) to
     * isEmpty(CharSequence)
     */
    public static boolean isEmpty(CharSequence cs) {
        return cs == null || cs.length() == 0;
    }

    /**
     * <p>
     * Checks if a CharSequence is not empty ("") and not null.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isNotEmpty(null)      = false
     * StringUtils.isNotEmpty("")        = false
     * StringUtils.isNotEmpty(" ")       = true
     * StringUtils.isNotEmpty("bob")     = true
     * StringUtils.isNotEmpty("  bob  ") = true
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if the CharSequence is not empty and not null
     * @since 3.0 Changed signature from isNotEmpty(String) to
     * isNotEmpty(CharSequence)
     */
    public static boolean isNotEmpty(CharSequence cs) {
        return !StringUtils.isEmpty(cs);
    }

    /**
     * <p>
     * Checks if a CharSequence is whitespace, empty ("") or null.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isBlank(null)      = true
     * StringUtils.isBlank("")        = true
     * StringUtils.isBlank(" ")       = true
     * StringUtils.isBlank("bob")     = false
     * StringUtils.isBlank("  bob  ") = false
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if the CharSequence is null, empty or whitespace
     * @since 3.0 Changed signature from isBlank(String) to
     * isBlank(CharSequence)
     */
    public static boolean isBlank(CharSequence cs) {
        int strLen;
        if (cs == null || (strLen = cs.length()) == 0) {
            return true;
        }
        for (int i = 0; i < strLen; i++) {
            if (!Character.isWhitespace(cs.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * <p>
     * Checks if a CharSequence is not empty (""), not null and not whitespace
     * only.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isNotBlank(null)      = false
     * StringUtils.isNotBlank("")        = false
     * StringUtils.isNotBlank(" ")       = false
     * StringUtils.isNotBlank("bob")     = true
     * StringUtils.isNotBlank("  bob  ") = true
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if the CharSequence is not empty and not null and
     * not whitespace
     * @since 3.0 Changed signature from isNotBlank(String) to
     * isNotBlank(CharSequence)
     */
    public static boolean isNotBlank(CharSequence cs) {
        return !StringUtils.isBlank(cs);
    }

    /**
     * <p>
     * Removes control characters (char &lt;= 32) from both ends of this String,
     * handling {@code null} by returning {@code null}.
     * </p>
     * <p/>
     * <p>
     * The String is trimmed using {@link String#trim()}. Trim removes start and
     * end characters &lt;= 32. To strip whitespace use {@link #strip(String)}.
     * </p>
     * <p/>
     * <p>
     * To trim your choice of characters, use the {@link #strip(String, String)}
     * methods.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.trim(null)          = null
     * StringUtils.trim("")            = ""
     * StringUtils.trim("     ")       = ""
     * StringUtils.trim("abc")         = "abc"
     * StringUtils.trim("    abc    ") = "abc"
     * </pre>
     *
     * @param str the String to be trimmed, may be null
     * @return the trimmed string, {@code null} if null String input
     */
    public static String trim(String str) {
        return str == null ? null : str.trim();
    }

    /**
     * <p>
     * Removes control characters (char &lt;= 32) from both ends of this String
     * returning {@code null} if the String is empty ("") after the trim or if
     * it is {@code null}.
     * <p/>
     * <p>
     * The String is trimmed using {@link String#trim()}. Trim removes start and
     * end characters &lt;= 32. To strip whitespace use
     * {@link #stripToNull(String)}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.trimToNull(null)          = null
     * StringUtils.trimToNull("")            = null
     * StringUtils.trimToNull("     ")       = null
     * StringUtils.trimToNull("abc")         = "abc"
     * StringUtils.trimToNull("    abc    ") = "abc"
     * </pre>
     *
     * @param str the String to be trimmed, may be null
     * @return the trimmed String, {@code null} if only chars &lt;= 32, empty or
     * null String input
     * @since 2.0
     */
    public static String trimToNull(String str) {
        String ts = trim(str);
        return isEmpty(ts) ? null : ts;
    }

    /**
     * <p>
     * Removes control characters (char &lt;= 32) from both ends of this String
     * returning an empty String ("") if the String is empty ("") after the trim
     * or if it is {@code null}.
     * <p/>
     * <p>
     * The String is trimmed using {@link String#trim()}. Trim removes start and
     * end characters &lt;= 32. To strip whitespace use
     * {@link #stripToEmpty(String)}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.trimToEmpty(null)          = ""
     * StringUtils.trimToEmpty("")            = ""
     * StringUtils.trimToEmpty("     ")       = ""
     * StringUtils.trimToEmpty("abc")         = "abc"
     * StringUtils.trimToEmpty("    abc    ") = "abc"
     * </pre>
     *
     * @param str the String to be trimmed, may be null
     * @return the trimmed String, or an empty String if {@code null} input
     * @since 2.0
     */
    public static String trimToEmpty(String str) {
        return str == null ? EMPTY : str.trim();
    }

    /**
     * <p>
     * Strips whitespace from the start and end of a String.
     * </p>
     * <p/>
     * <p>
     * This is similar to {@link #trim(String)} but removes whitespace.
     * Whitespace is defined by {@link Character#isWhitespace(char)}.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.strip(null)     = null
     * StringUtils.strip("")       = ""
     * StringUtils.strip("   ")    = ""
     * StringUtils.strip("abc")    = "abc"
     * StringUtils.strip("  abc")  = "abc"
     * StringUtils.strip("abc  ")  = "abc"
     * StringUtils.strip(" abc ")  = "abc"
     * StringUtils.strip(" ab c ") = "ab c"
     * </pre>
     *
     * @param str the String to remove whitespace from, may be null
     * @return the stripped String, {@code null} if null String input
     */
    public static String strip(String str) {
        return strip(str, null);
    }

    /**
     * <p>
     * Strips whitespace from the start and end of a String returning
     * {@code null} if the String is empty ("") after the strip.
     * </p>
     * <p/>
     * <p>
     * This is similar to {@link #trimToNull(String)} but removes whitespace.
     * Whitespace is defined by {@link Character#isWhitespace(char)}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.stripToNull(null)     = null
     * StringUtils.stripToNull("")       = null
     * StringUtils.stripToNull("   ")    = null
     * StringUtils.stripToNull("abc")    = "abc"
     * StringUtils.stripToNull("  abc")  = "abc"
     * StringUtils.stripToNull("abc  ")  = "abc"
     * StringUtils.stripToNull(" abc ")  = "abc"
     * StringUtils.stripToNull(" ab c ") = "ab c"
     * </pre>
     *
     * @param str the String to be stripped, may be null
     * @return the stripped String, {@code null} if whitespace, empty or null
     * String input
     * @since 2.0
     */
    public static String stripToNull(String str) {
        if (str == null) {
            return null;
        }
        String string = strip(str, null);
        return string.length() == 0 ? null : string;
    }

    /**
     * <p>
     * Strips whitespace from the start and end of a String returning an empty
     * String if {@code null} input.
     * </p>
     * <p/>
     * <p>
     * This is similar to {@link #trimToEmpty(String)} but removes whitespace.
     * Whitespace is defined by {@link Character#isWhitespace(char)}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.stripToEmpty(null)     = ""
     * StringUtils.stripToEmpty("")       = ""
     * StringUtils.stripToEmpty("   ")    = ""
     * StringUtils.stripToEmpty("abc")    = "abc"
     * StringUtils.stripToEmpty("  abc")  = "abc"
     * StringUtils.stripToEmpty("abc  ")  = "abc"
     * StringUtils.stripToEmpty(" abc ")  = "abc"
     * StringUtils.stripToEmpty(" ab c ") = "ab c"
     * </pre>
     *
     * @param str the String to be stripped, may be null
     * @return the trimmed String, or an empty String if {@code null} input
     * @since 2.0
     */
    public static String stripToEmpty(String str) {
        return str == null ? EMPTY : strip(str, null);
    }

    /**
     * <p>
     * Strips any of a set of characters from the start and end of a String.
     * This is similar to {@link String#trim()} but allows the characters to be
     * stripped to be controlled.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. An empty string ("")
     * input returns the empty string.
     * </p>
     * <p/>
     * <p>
     * If the stripChars String is {@code null}, whitespace is stripped as
     * defined by {@link Character#isWhitespace(char)}. Alternatively use
     * {@link #strip(String)}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.strip(null, *)          = null
     * StringUtils.strip("", *)            = ""
     * StringUtils.strip("abc", null)      = "abc"
     * StringUtils.strip("  abc", null)    = "abc"
     * StringUtils.strip("abc  ", null)    = "abc"
     * StringUtils.strip(" abc ", null)    = "abc"
     * StringUtils.strip("  abcyx", "xyz") = "  abc"
     * </pre>
     *
     * @param str        the String to remove characters from, may be null
     * @param stripChars the characters to remove, null treated as whitespace
     * @return the stripped String, {@code null} if null String input
     */
    public static String strip(String str, String stripChars) {
        if (isEmpty(str)) {
            return str;
        }
        String string = stripStart(str, stripChars);
        return stripEnd(string, stripChars);
    }

    /**
     * <p>
     * Strips any of a set of characters from the start of a String.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. An empty string ("")
     * input returns the empty string.
     * </p>
     * <p/>
     * <p>
     * If the stripChars String is {@code null}, whitespace is stripped as
     * defined by {@link Character#isWhitespace(char)}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.stripStart(null, *)          = null
     * StringUtils.stripStart("", *)            = ""
     * StringUtils.stripStart("abc", "")        = "abc"
     * StringUtils.stripStart("abc", null)      = "abc"
     * StringUtils.stripStart("  abc", null)    = "abc"
     * StringUtils.stripStart("abc  ", null)    = "abc  "
     * StringUtils.stripStart(" abc ", null)    = "abc "
     * StringUtils.stripStart("yxabc  ", "xyz") = "abc  "
     * </pre>
     *
     * @param str        the String to remove characters from, may be null
     * @param stripChars the characters to remove, null treated as whitespace
     * @return the stripped String, {@code null} if null String input
     */
    public static String stripStart(String str, String stripChars) {
        int strLen;
        if (str == null || (strLen = str.length()) == 0) {
            return str;
        }
        int start = 0;
        if (stripChars == null) {
            while (start != strLen && Character.isWhitespace(str.charAt(start))) {
                start++;
            }
        } else if (stripChars.length() == 0) {
            return str;
        } else {
            while (start != strLen && stripChars.indexOf(str.charAt(start)) != INDEX_NOT_FOUND) {
                start++;
            }
        }
        return str.substring(start);
    }

    /**
     * <p>
     * Strips any of a set of characters from the end of a String.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. An empty string ("")
     * input returns the empty string.
     * </p>
     * <p/>
     * <p>
     * If the stripChars String is {@code null}, whitespace is stripped as
     * defined by {@link Character#isWhitespace(char)}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.stripEnd(null, *)          = null
     * StringUtils.stripEnd("", *)            = ""
     * StringUtils.stripEnd("abc", "")        = "abc"
     * StringUtils.stripEnd("abc", null)      = "abc"
     * StringUtils.stripEnd("  abc", null)    = "  abc"
     * StringUtils.stripEnd("abc  ", null)    = "abc"
     * StringUtils.stripEnd(" abc ", null)    = " abc"
     * StringUtils.stripEnd("  abcyx", "xyz") = "  abc"
     * StringUtils.stripEnd("120.00", ".0")   = "12"
     * </pre>
     *
     * @param str        the String to remove characters from, may be null
     * @param stripChars the set of characters to remove, null treated as whitespace
     * @return the stripped String, {@code null} if null String input
     */
    public static String stripEnd(String str, String stripChars) {
        int end;
        if (str == null || (end = str.length()) == 0) {
            return str;
        }

        if (stripChars == null) {
            while (end != 0 && Character.isWhitespace(str.charAt(end - 1))) {
                end--;
            }
        } else if (stripChars.length() == 0) {
            return str;
        } else {
            while (end != 0 && stripChars.indexOf(str.charAt(end - 1)) != INDEX_NOT_FOUND) {
                end--;
            }
        }
        return str.substring(0, end);
    }

    /**
     * <p>
     * Strips whitespace from the start and end of every String in an array.
     * Whitespace is defined by {@link Character#isWhitespace(char)}.
     * </p>
     * <p/>
     * <p>
     * A new array is returned each time, except for length zero. A {@code null}
     * array will return {@code null}. An empty array will return itself. A
     * {@code null} array entry will be ignored.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.stripAll(null)             = null
     * StringUtils.stripAll([])               = []
     * StringUtils.stripAll(["abc", "  abc"]) = ["abc", "abc"]
     * StringUtils.stripAll(["abc  ", null])  = ["abc", null]
     * </pre>
     *
     * @param strs the array to remove whitespace from, may be null
     * @return the stripped Strings, {@code null} if null array input
     */
    public static String[] stripAll(String... strs) {
        return stripAll(strs, null);
    }

    /**
     * <p>
     * Strips any of a set of characters from the start and end of every String
     * in an array.
     * </p>
     * Whitespace is defined by {@link Character#isWhitespace(char)}.</p>
     * <p/>
     * <p>
     * A new array is returned each time, except for length zero. A {@code null}
     * array will return {@code null}. An empty array will return itself. A
     * {@code null} array entry will be ignored. A {@code null} stripChars will
     * strip whitespace as defined by {@link Character#isWhitespace(char)}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.stripAll(null, *)                = null
     * StringUtils.stripAll([], *)                  = []
     * StringUtils.stripAll(["abc", "  abc"], null) = ["abc", "abc"]
     * StringUtils.stripAll(["abc  ", null], null)  = ["abc", null]
     * StringUtils.stripAll(["abc  ", null], "yz")  = ["abc  ", null]
     * StringUtils.stripAll(["yabcz", null], "yz")  = ["abc", null]
     * </pre>
     *
     * @param strs       the array to remove characters from, may be null
     * @param stripChars the characters to remove, null treated as whitespace
     * @return the stripped Strings, {@code null} if null array input
     */
    public static String[] stripAll(String[] strs, String stripChars) {
        int strsLen;
        if (strs == null || (strsLen = strs.length) == 0) {
            return strs;
        }
        String[] newArr = new String[strsLen];
        for (int i = 0; i < strsLen; i++) {
            newArr[i] = strip(strs[i], stripChars);
        }
        return newArr;
    }

    /**
     * <p>
     * Removes diacritics (~= accents) from a string. The case will not be
     * altered.
     * </p>
     * <p>
     * For instance, '&agrave;' will be replaced by 'a'.
     * </p>
     * <p>
     * Note that ligatures will be left as is.
     * </p>
     * <p/>
     * <p>
     * This method will use the first available implementation of: Java 6's
     * {@link java.text.Normalizer}, Java 1.3&ndash;1.5's
     * {@code sun.text.Normalizer}
     * </p>
     * <p/>
     * <pre>
     * StringUtils.stripAccents(null)                = null
     * StringUtils.stripAccents("")                  = ""
     * StringUtils.stripAccents("control")           = "control"
     * StringUtils.stripAccents("&eacute;clair")     = "eclair"
     * </pre>
     *
     * @param input String to be stripped
     * @return input text with diacritics removed
     * @since 3.0
     */
    // See also Lucene's ASCIIFoldingFilter (Lucene 2.9) that replaces accented
    // characters by their unaccented equivalent (and uncommitted bug fix:
    // https://issues.apache.org/jira/browse/LUCENE-1343?focusedCommentId=12858907&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#action_12858907).
    public static String stripAccents(String input) {
        if (input == null) {
            return null;
        }
        try {
            String result;
            if (InitStripAccents.JAVA6NORMALIZE_METHOD != null) {
                result = removeAccentsJava6(input);
            } else if (InitStripAccents.SUN_DECOMPOSE_METHOD != null) {
                result = removeAccentsSUN(input);
            } else {
                throw new UnsupportedOperationException("The stripAccents(CharSequence) method requires at least"
                        + " Java6, but got: " + InitStripAccents.JAVA6EXCEPTION + "; or a Sun JVM: "
                        + InitStripAccents.SUN_EXCEPTION);
            }
            // Note that none of the above methods correctly remove ligatures...
            return result;
        } catch (IllegalArgumentException iae) {
            throw new RuntimeException("IllegalArgumentException occurred", iae);
        } catch (IllegalAccessException iae) {
            throw new RuntimeException("IllegalAccessException occurred", iae);
        } catch (InvocationTargetException ite) {
            throw new RuntimeException("InvocationTargetException occurred", ite);
        } catch (SecurityException se) {
            throw new RuntimeException("SecurityException occurred", se);
        }
    }

    /**
     * Use {@code java.text.Normalizer#normalize(CharSequence, Normalizer.Form)}
     * (but be careful, this class exists in Java 1.3, with an entirely
     * different meaning!)
     *
     * @param text the text to be processed
     * @return the processed string
     * @throws IllegalAccessException    may be thrown by a reflection call
     * @throws InvocationTargetException if a reflection call throws an exception
     * @throws IllegalStateException     if the {@code Normalizer} class is not available
     */
    private static String removeAccentsJava6(CharSequence text)
            throws IllegalAccessException, InvocationTargetException {
        if (InitStripAccents.JAVA6NORMALIZE_METHOD == null || InitStripAccents.JAVA6NORMALIZER_FORM_NFD == null) {
            throw new IllegalStateException("java.text.Normalizer is not available",
                    InitStripAccents.JAVA6EXCEPTION);
        }
        String result;
        result = (String) InitStripAccents.JAVA6NORMALIZE_METHOD.invoke(null,
                new Object[] { text, InitStripAccents.JAVA6NORMALIZER_FORM_NFD });
        result = InitStripAccents.JAVA6PATTERN.matcher(result).replaceAll("");//$NON-NLS-1$
        return result;
    }

    /**
     * Use {@code sun.text.Normalizer#decompose(String, boolean, int)}
     *
     * @param text the text to be processed
     * @return the processed string
     * @throws IllegalAccessException    may be thrown by a reflection call
     * @throws InvocationTargetException if a reflection call throws an exception
     * @throws IllegalStateException     if the {@code Normalizer} class is not available
     */
    private static String removeAccentsSUN(CharSequence text)
            throws IllegalAccessException, InvocationTargetException {
        if (InitStripAccents.SUN_DECOMPOSE_METHOD == null) {
            throw new IllegalStateException("sun.text.Normalizer is not available", InitStripAccents.SUN_EXCEPTION);
        }
        String result;
        result = (String) InitStripAccents.SUN_DECOMPOSE_METHOD.invoke(null,
                new Object[] { text, Boolean.FALSE, Integer.valueOf(0) });
        result = InitStripAccents.SUN_PATTERN.matcher(result).replaceAll("");//$NON-NLS-1$
        return result;
    }

    /**
     * IOD container for stripAccent() initialisation Create at 20131126
     * ?3:03:47
     *
     * @author KETQI
     */
    private static class InitStripAccents {
        // SUN internal, Java 1.3 -> Java 5
        private static final Throwable SUN_EXCEPTION;
        private static final Method SUN_DECOMPOSE_METHOD;
        private static final Pattern SUN_PATTERN = Pattern.compile("\\p{InCombiningDiacriticalMarks}+");//$NON-NLS-1$
        // Java 6+
        private static final Throwable JAVA6EXCEPTION;
        private static final Method JAVA6NORMALIZE_METHOD;
        private static final Object JAVA6NORMALIZER_FORM_NFD;
        private static final Pattern JAVA6PATTERN = SUN_PATTERN;

        static {
            // Set up defaults for final static fields
            Object java6NormalizerFormNFD = null;
            Method java6NormalizeMethod = null;
            Method sunDecomposeMethod = null;
            Throwable java6Exception = null;
            Throwable sunException = null;
            try {
                Class<?> normalizerFormClass = Thread.currentThread().getContextClassLoader()
                        .loadClass("java.text.Normalizer$Form");//$NON-NLS-1$
                java6NormalizerFormNFD = normalizerFormClass.getField("NFD").get(null);//$NON-NLS-1$
                Class<?> normalizerClass = Thread.currentThread().getContextClassLoader()
                        .loadClass("java.text.Normalizer");//$NON-NLS-1$
                java6NormalizeMethod = normalizerClass.getMethod("normalize", //$NON-NLS-1$
                        new Class[] { CharSequence.class, normalizerFormClass });//$NON-NLS-1$
            } catch (Exception e1) {
                // Only check for Sun method if Java 6 method is not available
                java6Exception = e1;
                try {
                    Class<?> normalizerClass = Thread.currentThread().getContextClassLoader()
                            .loadClass("sun.text.Normalizer");//$NON-NLS-1$
                    sunDecomposeMethod = normalizerClass.getMethod("decompose", //$NON-NLS-1$
                            new Class[] { String.class, Boolean.TYPE, Integer.TYPE });//$NON-NLS-1$
                } catch (Exception e2) {
                    sunException = e2;
                }
            }

            // Set up final static fields
            JAVA6EXCEPTION = java6Exception;
            JAVA6NORMALIZER_FORM_NFD = java6NormalizerFormNFD;
            JAVA6NORMALIZE_METHOD = java6NormalizeMethod;
            SUN_EXCEPTION = sunException;
            SUN_DECOMPOSE_METHOD = sunDecomposeMethod;
        }
    }

    /**
     * <p>
     * Compares two CharSequences, returning {@code true} if they are equal.
     * </p>
     * <p/>
     * <p>
     * {@code null}s are handled without exceptions. Two {@code null} references
     * are considered to be equal. The comparison is case sensitive.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.equals(null, null)   = true
     * StringUtils.equals(null, "abc")  = false
     * StringUtils.equals("abc", null)  = false
     * StringUtils.equals("abc", "abc") = true
     * StringUtils.equals("abc", "ABC") = false
     * </pre>
     *
     * @param cs1 the first CharSequence, may be null
     * @param cs2 the second CharSequence, may be null
     * @return {@code true} if the CharSequences are equal, case sensitive, or
     * both {@code null}
     * @see java.lang.String#equals(Object)
     * @since 3.0 Changed signature from equals(String, String) to
     * equals(CharSequence, CharSequence)
     */
    public static boolean equals(CharSequence cs1, CharSequence cs2) {
        return cs1 == null ? cs2 == null : cs1.equals(cs2);
    }

    /**
     * <p>
     * Compares two CharSequences, returning {@code true} if they are equal
     * ignoring the case.
     * </p>
     * <p/>
     * <p>
     * {@code null}s are handled without exceptions. Two {@code null} references
     * are considered equal. Comparison is case insensitive.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.equalsIgnoreCase(null, null)   = true
     * StringUtils.equalsIgnoreCase(null, "abc")  = false
     * StringUtils.equalsIgnoreCase("abc", null)  = false
     * StringUtils.equalsIgnoreCase("abc", "abc") = true
     * StringUtils.equalsIgnoreCase("abc", "ABC") = true
     * </pre>
     *
     * @param str1 the first CharSequence, may be null
     * @param str2 the second CharSequence, may be null
     * @return {@code true} if the CharSequence are equal, case insensitive, or
     * both {@code null}
     * @since 3.0 Changed signature from equalsIgnoreCase(String, String) to
     * equalsIgnoreCase(CharSequence, CharSequence)
     */
    public static boolean equalsIgnoreCase(CharSequence str1, CharSequence str2) {
        if (str1 == null || str2 == null) {
            return str1 == str2;
        } else {
            return CharSequenceUtils.regionMatches(str1, true, 0, str2, 0, Math.max(str1.length(), str2.length()));
        }
    }

    /**
     * <p>
     * Finds the first index within a CharSequence, handling {@code null}. This
     * method uses {@link String#indexOf(int, int)} if possible.
     * </p>
     * <p/>
     * <p>
     * A {@code null} or empty ("") CharSequence will return
     * {@code INDEX_NOT_FOUND (-1)}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOf(null, *)         = -1
     * StringUtils.indexOf("", *)           = -1
     * StringUtils.indexOf("aabaabaa", 'a') = 0
     * StringUtils.indexOf("aabaabaa", 'b') = 2
     * </pre>
     *
     * @param seq        the CharSequence to check, may be null
     * @param searchChar the character to find
     * @return the first index of the search character, -1 if no match or
     * {@code null} string input
     * @since 3.0 Changed signature from indexOf(String, int) to
     * indexOf(CharSequence, int)
     */
    public static int indexOf(CharSequence seq, int searchChar) {
        if (isEmpty(seq)) {
            return INDEX_NOT_FOUND;
        }
        return CharSequenceUtils.indexOf(seq, searchChar, 0);
    }

    /**
     * <p>
     * Finds the first index within a CharSequence from a start position,
     * handling {@code null}. This method uses {@link String#indexOf(int, int)}
     * if possible.
     * </p>
     * <p/>
     * <p>
     * A {@code null} or empty ("") CharSequence will return
     * {@code (INDEX_NOT_FOUND) -1}. A negative start position is treated as
     * zero. A start position greater than the string length returns {@code -1}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOf(null, *, *)          = -1
     * StringUtils.indexOf("", *, *)            = -1
     * StringUtils.indexOf("aabaabaa", 'b', 0)  = 2
     * StringUtils.indexOf("aabaabaa", 'b', 3)  = 5
     * StringUtils.indexOf("aabaabaa", 'b', 9)  = -1
     * StringUtils.indexOf("aabaabaa", 'b', -1) = 2
     * </pre>
     *
     * @param seq        the CharSequence to check, may be null
     * @param searchChar the character to find
     * @param startPos   the start position, negative treated as zero
     * @return the first index of the search character, -1 if no match or
     * {@code null} string input
     * @since 3.0 Changed signature from indexOf(String, int, int) to
     * indexOf(CharSequence, int, int)
     */
    public static int indexOf(CharSequence seq, int searchChar, int startPos) {
        if (isEmpty(seq)) {
            return INDEX_NOT_FOUND;
        }
        return CharSequenceUtils.indexOf(seq, searchChar, startPos);
    }

    /**
     * <p>
     * Finds the first index within a CharSequence, handling {@code null}. This
     * method uses {@link String#indexOf(String, int)} if possible.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOf(null, *)          = -1
     * StringUtils.indexOf(*, null)          = -1
     * StringUtils.indexOf("", "")           = 0
     * StringUtils.indexOf("", *)            = -1 (except when * = "")
     * StringUtils.indexOf("aabaabaa", "a")  = 0
     * StringUtils.indexOf("aabaabaa", "b")  = 2
     * StringUtils.indexOf("aabaabaa", "ab") = 1
     * StringUtils.indexOf("aabaabaa", "")   = 0
     * </pre>
     *
     * @param seq       the CharSequence to check, may be null
     * @param searchSeq the CharSequence to find, may be null
     * @return the first index of the search CharSequence, -1 if no match or
     * {@code null} string input
     * @since 3.0 Changed signature from indexOf(String, String) to
     * indexOf(CharSequence, CharSequence)
     */
    public static int indexOf(CharSequence seq, CharSequence searchSeq) {
        if (seq == null || searchSeq == null) {
            return INDEX_NOT_FOUND;
        }
        return CharSequenceUtils.indexOf(seq, searchSeq, 0);
    }

    /**
     * <p>
     * Finds the first index within a CharSequence, handling {@code null}. This
     * method uses {@link String#indexOf(String, int)} if possible.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}. A negative start
     * position is treated as zero. An empty ("") search CharSequence always
     * matches. A start position greater than the string length only matches an
     * empty search CharSequence.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOf(null, *, *)          = -1
     * StringUtils.indexOf(*, null, *)          = -1
     * StringUtils.indexOf("", "", 0)           = 0
     * StringUtils.indexOf("", *, 0)            = -1 (except when * = "")
     * StringUtils.indexOf("aabaabaa", "a", 0)  = 0
     * StringUtils.indexOf("aabaabaa", "b", 0)  = 2
     * StringUtils.indexOf("aabaabaa", "ab", 0) = 1
     * StringUtils.indexOf("aabaabaa", "b", 3)  = 5
     * StringUtils.indexOf("aabaabaa", "b", 9)  = -1
     * StringUtils.indexOf("aabaabaa", "b", -1) = 2
     * StringUtils.indexOf("aabaabaa", "", 2)   = 2
     * StringUtils.indexOf("abc", "", 9)        = 3
     * </pre>
     *
     * @param seq       the CharSequence to check, may be null
     * @param searchSeq the CharSequence to find, may be null
     * @param startPos  the start position, negative treated as zero
     * @return the first index of the search CharSequence, -1 if no match or
     * {@code null} string input
     * @since 3.0 Changed signature from indexOf(String, String, int) to
     * indexOf(CharSequence, CharSequence, int)
     */
    public static int indexOf(CharSequence seq, CharSequence searchSeq, int startPos) {
        if (seq == null || searchSeq == null) {
            return INDEX_NOT_FOUND;
        }
        return CharSequenceUtils.indexOf(seq, searchSeq, startPos);
    }

    /**
     * <p>
     * Finds the n-th index within a CharSequence, handling {@code null}. This
     * method uses {@link String#indexOf(String)} if possible.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.ordinalIndexOf(null, *, *)          = -1
     * StringUtils.ordinalIndexOf(*, null, *)          = -1
     * StringUtils.ordinalIndexOf("", "", *)           = 0
     * StringUtils.ordinalIndexOf("aabaabaa", "a", 1)  = 0
     * StringUtils.ordinalIndexOf("aabaabaa", "a", 2)  = 1
     * StringUtils.ordinalIndexOf("aabaabaa", "b", 1)  = 2
     * StringUtils.ordinalIndexOf("aabaabaa", "b", 2)  = 5
     * StringUtils.ordinalIndexOf("aabaabaa", "ab", 1) = 1
     * StringUtils.ordinalIndexOf("aabaabaa", "ab", 2) = 4
     * StringUtils.ordinalIndexOf("aabaabaa", "", 1)   = 0
     * StringUtils.ordinalIndexOf("aabaabaa", "", 2)   = 0
     * </pre>
     * <p/>
     * <p>
     * Note that 'head(CharSequence str, int n)' may be implemented as:
     * </p>
     * <p/>
     * <pre>
     * str.substring(0, lastOrdinalIndexOf(str, &quot;\n&quot;, n))
     * </pre>
     *
     * @param str       the CharSequence to check, may be null
     * @param searchStr the CharSequence to find, may be null
     * @param ordinal   the n-th {@code searchStr} to find
     * @return the n-th index of the search CharSequence, {@code -1} (
     * {@code INDEX_NOT_FOUND}) if no match or {@code null} string input
     * @since 3.0 Changed signature from ordinalIndexOf(String, String, int) to
     * ordinalIndexOf(CharSequence, CharSequence, int)
     */
    public static int ordinalIndexOf(CharSequence str, CharSequence searchStr, int ordinal) {
        return ordinalIndexOf(str, searchStr, ordinal, false);
    }

    /**
     * <p>
     * Finds the n-th index within a String, handling {@code null}. This method
     * uses {@link String#indexOf(String)} if possible.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}.
     * </p>
     *
     * @param str       the CharSequence to check, may be null
     * @param searchStr the CharSequence to find, may be null
     * @param ordinal   the n-th {@code searchStr} to find
     * @param lastIndex true if lastOrdinalIndexOf() otherwise false if
     *                  ordinalIndexOf()
     * @return the n-th index of the search CharSequence, {@code -1} (
     * {@code INDEX_NOT_FOUND}) if no match or {@code null} string input
     */
    // Shared code between ordinalIndexOf(String,String,int) and
    // lastOrdinalIndexOf(String,String,int)
    private static int ordinalIndexOf(CharSequence str, CharSequence searchStr, int ordinal, boolean lastIndex) {
        if (str == null || searchStr == null || ordinal <= 0) {
            return INDEX_NOT_FOUND;
        }
        if (searchStr.length() == 0) {
            return lastIndex ? str.length() : 0;
        }
        int found = 0;
        int index = lastIndex ? str.length() : INDEX_NOT_FOUND;
        do {
            if (lastIndex) {
                index = CharSequenceUtils.lastIndexOf(str, searchStr, index - 1);
            } else {
                index = CharSequenceUtils.indexOf(str, searchStr, index + 1);
            }
            if (index < 0) {
                return index;
            }
            found++;
        } while (found < ordinal);
        return index;
    }

    /**
     * <p>
     * Case in-sensitive find of the first index within a CharSequence.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}. A negative start
     * position is treated as zero. An empty ("") search CharSequence always
     * matches. A start position greater than the string length only matches an
     * empty search CharSequence.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOfIgnoreCase(null, *)          = -1
     * StringUtils.indexOfIgnoreCase(*, null)          = -1
     * StringUtils.indexOfIgnoreCase("", "")           = 0
     * StringUtils.indexOfIgnoreCase("aabaabaa", "a")  = 0
     * StringUtils.indexOfIgnoreCase("aabaabaa", "b")  = 2
     * StringUtils.indexOfIgnoreCase("aabaabaa", "ab") = 1
     * </pre>
     *
     * @param str       the CharSequence to check, may be null
     * @param searchStr the CharSequence to find, may be null
     * @return the first index of the search CharSequence, -1 if no match or
     * {@code null} string input
     * @since 3.0 Changed signature from indexOfIgnoreCase(String, String) to
     * indexOfIgnoreCase(CharSequence, CharSequence)
     */
    public static int indexOfIgnoreCase(CharSequence str, CharSequence searchStr) {
        return indexOfIgnoreCase(str, searchStr, 0);
    }

    /**
     * <p>
     * Case in-sensitive find of the first index within a CharSequence from the
     * specified position.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}. A negative start
     * position is treated as zero. An empty ("") search CharSequence always
     * matches. A start position greater than the string length only matches an
     * empty search CharSequence.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOfIgnoreCase(null, *, *)          = -1
     * StringUtils.indexOfIgnoreCase(*, null, *)          = -1
     * StringUtils.indexOfIgnoreCase("", "", 0)           = 0
     * StringUtils.indexOfIgnoreCase("aabaabaa", "A", 0)  = 0
     * StringUtils.indexOfIgnoreCase("aabaabaa", "B", 0)  = 2
     * StringUtils.indexOfIgnoreCase("aabaabaa", "AB", 0) = 1
     * StringUtils.indexOfIgnoreCase("aabaabaa", "B", 3)  = 5
     * StringUtils.indexOfIgnoreCase("aabaabaa", "B", 9)  = -1
     * StringUtils.indexOfIgnoreCase("aabaabaa", "B", -1) = 2
     * StringUtils.indexOfIgnoreCase("aabaabaa", "", 2)   = 2
     * StringUtils.indexOfIgnoreCase("abc", "", 9)        = 3
     * </pre>
     *
     * @param str       the CharSequence to check, may be null
     * @param searchStr the CharSequence to find, may be null
     * @param start     the start position, negative treated as zero
     * @return the first index of the search CharSequence, -1 if no match or
     * {@code null} string input
     * @since 3.0 Changed signature from indexOfIgnoreCase(String, String, int)
     * to indexOfIgnoreCase(CharSequence, CharSequence, int)
     */
    public static int indexOfIgnoreCase(CharSequence str, CharSequence searchStr, int start) {
        if (str == null || searchStr == null) {
            return INDEX_NOT_FOUND;
        }
        int startPos = start;
        if (startPos < 0) {
            startPos = 0;
        }
        int endLimit = str.length() - searchStr.length() + 1;
        if (startPos > endLimit) {
            return INDEX_NOT_FOUND;
        }
        if (searchStr.length() == 0) {
            return startPos;
        }
        for (int i = startPos; i < endLimit; i++) {
            if (CharSequenceUtils.regionMatches(str, true, i, searchStr, 0, searchStr.length())) {
                return i;
            }
        }
        return INDEX_NOT_FOUND;
    }

    /**
     * <p>
     * Finds the last index within a CharSequence, handling {@code null}. This
     * method uses {@link String#lastIndexOf(int)} if possible.
     * </p>
     * <p/>
     * <p>
     * A {@code null} or empty ("") CharSequence will return {@code -1}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.lastIndexOf(null, *)         = -1
     * StringUtils.lastIndexOf("", *)           = -1
     * StringUtils.lastIndexOf("aabaabaa", 'a') = 7
     * StringUtils.lastIndexOf("aabaabaa", 'b') = 5
     * </pre>
     *
     * @param seq        the CharSequence to check, may be null
     * @param searchChar the character to find
     * @return the last index of the search character, -1 if no match or
     * {@code null} string input
     * @since 3.0 Changed signature from lastIndexOf(String, int) to
     * lastIndexOf(CharSequence, int)
     */
    public static int lastIndexOf(CharSequence seq, int searchChar) {
        if (isEmpty(seq)) {
            return INDEX_NOT_FOUND;
        }
        return CharSequenceUtils.lastIndexOf(seq, searchChar, seq.length());
    }

    /**
     * <p>
     * Finds the last index within a CharSequence from a start position,
     * handling {@code null}. This method uses
     * {@link String#lastIndexOf(int, int)} if possible.
     * </p>
     * <p/>
     * <p>
     * A {@code null} or empty ("") CharSequence will return {@code -1}. A
     * negative start position returns {@code -1}. A start position greater than
     * the string length searches the whole string.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.lastIndexOf(null, *, *)          = -1
     * StringUtils.lastIndexOf("", *,  *)           = -1
     * StringUtils.lastIndexOf("aabaabaa", 'b', 8)  = 5
     * StringUtils.lastIndexOf("aabaabaa", 'b', 4)  = 2
     * StringUtils.lastIndexOf("aabaabaa", 'b', 0)  = -1
     * StringUtils.lastIndexOf("aabaabaa", 'b', 9)  = 5
     * StringUtils.lastIndexOf("aabaabaa", 'b', -1) = -1
     * StringUtils.lastIndexOf("aabaabaa", 'a', 0)  = 0
     * </pre>
     *
     * @param seq        the CharSequence to check, may be null
     * @param searchChar the character to find
     * @param startPos   the start position
     * @return the last index of the search character, -1 if no match or
     * {@code null} string input
     * @since 3.0 Changed signature from lastIndexOf(String, int, int) to
     * lastIndexOf(CharSequence, int, int)
     */
    public static int lastIndexOf(CharSequence seq, int searchChar, int startPos) {
        if (isEmpty(seq)) {
            return INDEX_NOT_FOUND;
        }
        return CharSequenceUtils.lastIndexOf(seq, searchChar, startPos);
    }

    /**
     * <p>
     * Finds the last index within a CharSequence, handling {@code null}. This
     * method uses {@link String#lastIndexOf(String)} if possible.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.lastIndexOf(null, *)          = -1
     * StringUtils.lastIndexOf(*, null)          = -1
     * StringUtils.lastIndexOf("", "")           = 0
     * StringUtils.lastIndexOf("aabaabaa", "a")  = 7
     * StringUtils.lastIndexOf("aabaabaa", "b")  = 5
     * StringUtils.lastIndexOf("aabaabaa", "ab") = 4
     * StringUtils.lastIndexOf("aabaabaa", "")   = 8
     * </pre>
     *
     * @param seq       the CharSequence to check, may be null
     * @param searchSeq the CharSequence to find, may be null
     * @return the last index of the search String, -1 if no match or
     * {@code null} string input
     * @since 3.0 Changed signature from lastIndexOf(String, String) to
     * lastIndexOf(CharSequence, CharSequence)
     */
    public static int lastIndexOf(CharSequence seq, CharSequence searchSeq) {
        if (seq == null || searchSeq == null) {
            return INDEX_NOT_FOUND;
        }
        return CharSequenceUtils.lastIndexOf(seq, searchSeq, seq.length());
    }

    /**
     * <p>
     * Finds the n-th last index within a String, handling {@code null}. This
     * method uses {@link String#lastIndexOf(String)}.
     * </p>
     * <p/>
     * <p>
     * A {@code null} String will return {@code -1}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.lastOrdinalIndexOf(null, *, *)          = -1
     * StringUtils.lastOrdinalIndexOf(*, null, *)          = -1
     * StringUtils.lastOrdinalIndexOf("", "", *)           = 0
     * StringUtils.lastOrdinalIndexOf("aabaabaa", "a", 1)  = 7
     * StringUtils.lastOrdinalIndexOf("aabaabaa", "a", 2)  = 6
     * StringUtils.lastOrdinalIndexOf("aabaabaa", "b", 1)  = 5
     * StringUtils.lastOrdinalIndexOf("aabaabaa", "b", 2)  = 2
     * StringUtils.lastOrdinalIndexOf("aabaabaa", "ab", 1) = 4
     * StringUtils.lastOrdinalIndexOf("aabaabaa", "ab", 2) = 1
     * StringUtils.lastOrdinalIndexOf("aabaabaa", "", 1)   = 8
     * StringUtils.lastOrdinalIndexOf("aabaabaa", "", 2)   = 8
     * </pre>
     * <p/>
     * <p>
     * Note that 'tail(CharSequence str, int n)' may be implemented as:
     * </p>
     * <p/>
     * <pre>
     * str.substring(lastOrdinalIndexOf(str, &quot;\n&quot;, n) + 1)
     * </pre>
     *
     * @param str       the CharSequence to check, may be null
     * @param searchStr the CharSequence to find, may be null
     * @param ordinal   the n-th last {@code searchStr} to find
     * @return the n-th last index of the search CharSequence, {@code -1} (
     * {@code INDEX_NOT_FOUND}) if no match or {@code null} string input
     * @since 3.0 Changed signature from lastOrdinalIndexOf(String, String, int)
     * to lastOrdinalIndexOf(CharSequence, CharSequence, int)
     */
    public static int lastOrdinalIndexOf(CharSequence str, CharSequence searchStr, int ordinal) {
        return ordinalIndexOf(str, searchStr, ordinal, true);
    }

    /**
     * <p>
     * Finds the first index within a CharSequence, handling {@code null}. This
     * method uses {@link String#lastIndexOf(String, int)} if possible.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}. A negative start
     * position returns {@code -1}. An empty ("") search CharSequence always
     * matches unless the start position is negative. A start position greater
     * than the string length searches the whole string.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.lastIndexOf(null, *, *)          = -1
     * StringUtils.lastIndexOf(*, null, *)          = -1
     * StringUtils.lastIndexOf("aabaabaa", "a", 8)  = 7
     * StringUtils.lastIndexOf("aabaabaa", "b", 8)  = 5
     * StringUtils.lastIndexOf("aabaabaa", "ab", 8) = 4
     * StringUtils.lastIndexOf("aabaabaa", "b", 9)  = 5
     * StringUtils.lastIndexOf("aabaabaa", "b", -1) = -1
     * StringUtils.lastIndexOf("aabaabaa", "a", 0)  = 0
     * StringUtils.lastIndexOf("aabaabaa", "b", 0)  = -1
     * </pre>
     *
     * @param seq       the CharSequence to check, may be null
     * @param searchSeq the CharSequence to find, may be null
     * @param startPos  the start position, negative treated as zero
     * @return the first index of the search CharSequence, -1 if no match or
     * {@code null} string input
     * @since 3.0 Changed signature from lastIndexOf(String, String, int) to
     * lastIndexOf(CharSequence, CharSequence, int)
     */
    public static int lastIndexOf(CharSequence seq, CharSequence searchSeq, int startPos) {
        if (seq == null || searchSeq == null) {
            return INDEX_NOT_FOUND;
        }
        return CharSequenceUtils.lastIndexOf(seq, searchSeq, startPos);
    }

    /**
     * <p>
     * Case in-sensitive find of the last index within a CharSequence.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}. A negative start
     * position returns {@code -1}. An empty ("") search CharSequence always
     * matches unless the start position is negative. A start position greater
     * than the string length searches the whole string.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.lastIndexOfIgnoreCase(null, *)          = -1
     * StringUtils.lastIndexOfIgnoreCase(*, null)          = -1
     * StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A")  = 7
     * StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B")  = 5
     * StringUtils.lastIndexOfIgnoreCase("aabaabaa", "AB") = 4
     * </pre>
     *
     * @param str       the CharSequence to check, may be null
     * @param searchStr the CharSequence to find, may be null
     * @return the first index of the search CharSequence, -1 if no match or
     * {@code null} string input
     * @since 3.0 Changed signature from lastIndexOfIgnoreCase(String, String)
     * to lastIndexOfIgnoreCase(CharSequence, CharSequence)
     */
    public static int lastIndexOfIgnoreCase(CharSequence str, CharSequence searchStr) {
        if (str == null || searchStr == null) {
            return INDEX_NOT_FOUND;
        }
        return lastIndexOfIgnoreCase(str, searchStr, str.length());
    }

    /**
     * <p>
     * Case in-sensitive find of the last index within a CharSequence from the
     * specified position.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}. A negative start
     * position returns {@code -1}. An empty ("") search CharSequence always
     * matches unless the start position is negative. A start position greater
     * than the string length searches the whole string.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.lastIndexOfIgnoreCase(null, *, *)          = -1
     * StringUtils.lastIndexOfIgnoreCase(*, null, *)          = -1
     * StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A", 8)  = 7
     * StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 8)  = 5
     * StringUtils.lastIndexOfIgnoreCase("aabaabaa", "AB", 8) = 4
     * StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 9)  = 5
     * StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", -1) = -1
     * StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A", 0)  = 0
     * StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 0)  = -1
     * </pre>
     *
     * @param str       the CharSequence to check, may be null
     * @param searchStr the CharSequence to find, may be null
     * @param start     the start position
     * @return the first index of the search CharSequence, -1 if no match or
     * {@code null} input
     * @since 3.0 Changed signature from lastIndexOfIgnoreCase(String, String,
     * int) to lastIndexOfIgnoreCase(CharSequence, CharSequence, int)
     */
    public static int lastIndexOfIgnoreCase(CharSequence str, CharSequence searchStr, int start) {
        if (str == null || searchStr == null) {
            return INDEX_NOT_FOUND;
        }
        int startPos = start;
        if (startPos > str.length() - searchStr.length()) {
            startPos = str.length() - searchStr.length();
        }
        if (startPos < 0) {
            return INDEX_NOT_FOUND;
        }
        if (searchStr.length() == 0) {
            return startPos;
        }

        for (int i = startPos; i >= 0; i--) {
            if (CharSequenceUtils.regionMatches(str, true, i, searchStr, 0, searchStr.length())) {
                return i;
            }
        }
        return INDEX_NOT_FOUND;
    }

    /**
     * <p>
     * Checks if CharSequence contains a search character, handling {@code null}
     * . This method uses {@link String#indexOf(int)} if possible.
     * </p>
     * <p/>
     * <p>
     * A {@code null} or empty ("") CharSequence will return {@code false}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.contains(null, *)    = false
     * StringUtils.contains("", *)      = false
     * StringUtils.contains("abc", 'a') = true
     * StringUtils.contains("abc", 'z') = false
     * </pre>
     *
     * @param seq        the CharSequence to check, may be null
     * @param searchChar the character to find
     * @return true if the CharSequence contains the search character, false if
     * not or {@code null} string input
     * @since 3.0 Changed signature from contains(String, int) to
     * contains(CharSequence, int)
     */
    public static boolean contains(CharSequence seq, int searchChar) {
        if (isEmpty(seq)) {
            return false;
        }
        return CharSequenceUtils.indexOf(seq, searchChar, 0) >= 0;
    }

    /**
     * <p>
     * Checks if CharSequence contains a search CharSequence, handling
     * {@code null}. This method uses {@link String#indexOf(String)} if
     * possible.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code false}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.contains(null, *)     = false
     * StringUtils.contains(*, null)     = false
     * StringUtils.contains("", "")      = true
     * StringUtils.contains("abc", "")   = true
     * StringUtils.contains("abc", "a")  = true
     * StringUtils.contains("abc", "z")  = false
     * </pre>
     *
     * @param seq       the CharSequence to check, may be null
     * @param searchSeq the CharSequence to find, may be null
     * @return true if the CharSequence contains the search CharSequence, false
     * if not or {@code null} string input
     * @since 3.0 Changed signature from contains(String, String) to
     * contains(CharSequence, CharSequence)
     */
    public static boolean contains(CharSequence seq, CharSequence searchSeq) {
        if (seq == null || searchSeq == null) {
            return false;
        }
        return CharSequenceUtils.indexOf(seq, searchSeq, 0) >= 0;
    }

    /**
     * <p>
     * Checks if CharSequence contains a search CharSequence irrespective of
     * case, handling {@code null}. Case-insensitivity is defined as by
     * {@link String#equalsIgnoreCase(String)}.
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code false}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.contains(null, *) = false
     * StringUtils.contains(*, null) = false
     * StringUtils.contains("", "") = true
     * StringUtils.contains("abc", "") = true
     * StringUtils.contains("abc", "a") = true
     * StringUtils.contains("abc", "z") = false
     * StringUtils.contains("abc", "A") = true
     * StringUtils.contains("abc", "Z") = false
     * </pre>
     *
     * @param str       the CharSequence to check, may be null
     * @param searchStr the CharSequence to find, may be null
     * @return true if the CharSequence contains the search CharSequence
     * irrespective of case or false if not or {@code null} string input
     * @since 3.0 Changed signature from containsIgnoreCase(String, String) to
     * containsIgnoreCase(CharSequence, CharSequence)
     */
    public static boolean containsIgnoreCase(CharSequence str, CharSequence searchStr) {
        if (str == null || searchStr == null) {
            return false;
        }
        int len = searchStr.length();
        int max = str.length() - len;
        for (int i = 0; i <= max; i++) {
            if (CharSequenceUtils.regionMatches(str, true, i, searchStr, 0, len)) {
                return true;
            }
        }
        return false;
    }

    /**
     * Check whether the given CharSequence contains any whitespace characters.
     *
     * @param seq the CharSequence to check (may be {@code null})
     * @return {@code true} if the CharSequence is not empty and contains at
     * least 1 whitespace character
     * @see java.lang.Character#isWhitespace
     * @since 3.0
     */
    // From org.springframework.util.StringUtils, under Apache License 2.0
    public static boolean containsWhitespace(CharSequence seq) {
        if (isEmpty(seq)) {
            return false;
        }
        int strLen = seq.length();
        for (int i = 0; i < strLen; i++) {
            if (Character.isWhitespace(seq.charAt(i))) {
                return true;
            }
        }
        return false;
    }

    /**
     * <p>
     * Search a CharSequence to find the first index of any character in the
     * given set of characters.
     * </p>
     * <p/>
     * <p>
     * A {@code null} String will return {@code -1}. A {@code null} or zero
     * length search array will return {@code -1}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOfAny(null, *)                = -1
     * StringUtils.indexOfAny("", *)                  = -1
     * StringUtils.indexOfAny(*, null)                = -1
     * StringUtils.indexOfAny(*, [])                  = -1
     * StringUtils.indexOfAny("zzabyycdxx",['z','a']) = 0
     * StringUtils.indexOfAny("zzabyycdxx",['b','y']) = 3
     * StringUtils.indexOfAny("aba", ['z'])           = -1
     * </pre>
     *
     * @param cs          the CharSequence to check, may be null
     * @param searchChars the chars to search for, may be null
     * @return the index of any of the chars, -1 if no match or null input
     * @since 3.0 Changed signature from indexOfAny(String, char[]) to
     * indexOfAny(CharSequence, char...)
     */
    public static int indexOfAny(CharSequence cs, char... searchChars) {
        if (isEmpty(cs) || searchChars == null) {
            return INDEX_NOT_FOUND;
        }
        int csLen = cs.length();
        int csLast = csLen - 1;
        int searchLen = searchChars.length;
        int searchLast = searchLen - 1;
        for (int i = 0; i < csLen; i++) {
            char ch = cs.charAt(i);
            for (int j = 0; j < searchLen; j++) {
                if (searchChars[j] == ch) {
                    if (i < csLast && j < searchLast && Character.isHighSurrogate(ch)) {
                        // ch is a supplementary character
                        if (searchChars[j + 1] == cs.charAt(i + 1)) {
                            return i;
                        }
                    } else {
                        return i;
                    }
                }
            }
        }
        return INDEX_NOT_FOUND;
    }

    /**
     * <p>
     * Search a CharSequence to find the first index of any character in the
     * given set of characters.
     * </p>
     * <p/>
     * <p>
     * A {@code null} String will return {@code -1}. A {@code null} search
     * string will return {@code -1}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOfAny(null, *)            = -1
     * StringUtils.indexOfAny("", *)              = -1
     * StringUtils.indexOfAny(*, null)            = -1
     * StringUtils.indexOfAny(*, "")              = -1
     * StringUtils.indexOfAny("zzabyycdxx", "za") = 0
     * StringUtils.indexOfAny("zzabyycdxx", "by") = 3
     * StringUtils.indexOfAny("aba","z")          = -1
     * </pre>
     *
     * @param cs          the CharSequence to check, may be null
     * @param searchChars the chars to search for, may be null
     * @return the index of any of the chars, -1 if no match or null input
     * @since 3.0 Changed signature from indexOfAny(String, String) to
     * indexOfAny(CharSequence, String)
     */
    public static int indexOfAny(CharSequence cs, String searchChars) {
        if (isEmpty(cs) || isEmpty(searchChars)) {
            return INDEX_NOT_FOUND;
        }
        return indexOfAny(cs, searchChars.toCharArray());
    }

    /**
     * <p>
     * Checks if the CharSequence contains any character in the given set of
     * characters.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code false}. A {@code null} or
     * zero length search array will return {@code false}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.containsAny(null, *)                = false
     * StringUtils.containsAny("", *)                  = false
     * StringUtils.containsAny(*, null)                = false
     * StringUtils.containsAny(*, [])                  = false
     * StringUtils.containsAny("zzabyycdxx",['z','a']) = true
     * StringUtils.containsAny("zzabyycdxx",['b','y']) = true
     * StringUtils.containsAny("aba", ['z'])           = false
     * </pre>
     *
     * @param cs          the CharSequence to check, may be null
     * @param searchChars the chars to search for, may be null
     * @return the {@code true} if any of the chars are found, {@code false} if
     * no match or null input
     * @since 3.0 Changed signature from containsAny(String, char[]) to
     * containsAny(CharSequence, char...)
     */
    public static boolean containsAny(CharSequence cs, char... searchChars) {
        if (isEmpty(cs) || searchChars == null) {
            return false;
        }
        int csLength = cs.length();
        int searchLength = searchChars.length;
        int csLast = csLength - 1;
        int searchLast = searchLength - 1;
        for (int i = 0; i < csLength; i++) {
            char ch = cs.charAt(i);
            for (int j = 0; j < searchLength; j++) {
                if (searchChars[j] == ch) {
                    if (Character.isHighSurrogate(ch)) {
                        if (j == searchLast) {
                            // missing low surrogate, fine, like
                            // String.indexOf(String)
                            return true;
                        }
                        if (i < csLast && searchChars[j + 1] == cs.charAt(i + 1)) {
                            return true;
                        }
                    } else {
                        // ch is in the Basic Multilingual Plane
                        return true;
                    }
                }
            }
        }
        return false;
    }

    /**
     * <p>
     * Checks if the CharSequence contains any character in the given set of
     * characters.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code false}. A {@code null}
     * search CharSequence will return {@code false}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.containsAny(null, *)            = false
     * StringUtils.containsAny("", *)              = false
     * StringUtils.containsAny(*, null)            = false
     * StringUtils.containsAny(*, "")              = false
     * StringUtils.containsAny("zzabyycdxx", "za") = true
     * StringUtils.containsAny("zzabyycdxx", "by") = true
     * StringUtils.containsAny("aba","z")          = false
     * </pre>
     *
     * @param cs          the CharSequence to check, may be null
     * @param searchChars the chars to search for, may be null
     * @return the {@code true} if any of the chars are found, {@code false} if
     * no match or null input
     * @since 3.0 Changed signature from containsAny(String, String) to
     * containsAny(CharSequence, CharSequence)
     */
    public static boolean containsAny(CharSequence cs, CharSequence searchChars) {
        if (searchChars == null) {
            return false;
        }
        return containsAny(cs, CharSequenceUtils.toCharArray(searchChars));
    }

    /**
     * <p>
     * Searches a CharSequence to find the first index of any character not in
     * the given set of characters.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}. A {@code null} or
     * zero length search array will return {@code -1}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOfAnyBut(null, *)                              = -1
     * StringUtils.indexOfAnyBut("", *)                                = -1
     * StringUtils.indexOfAnyBut(*, null)                              = -1
     * StringUtils.indexOfAnyBut(*, [])                                = -1
     * StringUtils.indexOfAnyBut("zzabyycdxx", new char[] {'z', 'a'} ) = 3
     * StringUtils.indexOfAnyBut("aba", new char[] {'z'} )             = 0
     * StringUtils.indexOfAnyBut("aba", new char[] {'a', 'b'} )        = -1
     *
     * </pre>
     *
     * @param cs          the CharSequence to check, may be null
     * @param searchChars the chars to search for, may be null
     * @return the index of any of the chars, -1 if no match or null input
     * @since 3.0 Changed signature from indexOfAnyBut(String, char[]) to
     * indexOfAnyBut(CharSequence, char...)
     */
    public static int indexOfAnyBut(CharSequence cs, char... searchChars) {
        if (isEmpty(cs) || searchChars == null) {
            return INDEX_NOT_FOUND;
        }
        int csLen = cs.length();
        int csLast = csLen - 1;
        int searchLen = searchChars.length;
        int searchLast = searchLen - 1;
        outer: for (int i = 0; i < csLen; i++) {
            char ch = cs.charAt(i);
            for (int j = 0; j < searchLen; j++) {
                if (searchChars[j] == ch) {
                    if (i < csLast && j < searchLast && Character.isHighSurrogate(ch)) {
                        if (searchChars[j + 1] == cs.charAt(i + 1)) {
                            continue outer;
                        }
                    } else {
                        continue outer;
                    }
                }
            }
            return i;
        }
        return INDEX_NOT_FOUND;
    }

    /**
     * <p>
     * Search a CharSequence to find the first index of any character not in the
     * given set of characters.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}. A {@code null} or
     * empty search string will return {@code -1}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOfAnyBut(null, *)            = -1
     * StringUtils.indexOfAnyBut("", *)              = -1
     * StringUtils.indexOfAnyBut(*, null)            = -1
     * StringUtils.indexOfAnyBut(*, "")              = -1
     * StringUtils.indexOfAnyBut("zzabyycdxx", "za") = 3
     * StringUtils.indexOfAnyBut("zzabyycdxx", "")   = -1
     * StringUtils.indexOfAnyBut("aba","ab")         = -1
     * </pre>
     *
     * @param seq         the CharSequence to check, may be null
     * @param searchChars the chars to search for, may be null
     * @return the index of any of the chars, -1 if no match or null input
     * @since 3.0 Changed signature from indexOfAnyBut(String, String) to
     * indexOfAnyBut(CharSequence, CharSequence)
     */
    public static int indexOfAnyBut(CharSequence seq, CharSequence searchChars) {
        if (isEmpty(seq) || isEmpty(searchChars)) {
            return INDEX_NOT_FOUND;
        }
        int strLen = seq.length();
        for (int i = 0; i < strLen; i++) {
            char ch = seq.charAt(i);
            boolean chFound = CharSequenceUtils.indexOf(searchChars, ch, 0) >= 0;
            if (i + 1 < strLen && Character.isHighSurrogate(ch)) {
                char ch2 = seq.charAt(i + 1);
                if (chFound && CharSequenceUtils.indexOf(searchChars, ch2, 0) < 0) {
                    return i;
                }
            } else {
                if (!chFound) {
                    return i;
                }
            }
        }
        return INDEX_NOT_FOUND;
    }

    /**
     * <p>
     * Checks if the CharSequence contains only certain characters.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code false}. A {@code null}
     * valid character array will return {@code false}. An empty CharSequence
     * (length()=0) always returns {@code true}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.containsOnly(null, *)       = false
     * StringUtils.containsOnly(*, null)       = false
     * StringUtils.containsOnly("", *)         = true
     * StringUtils.containsOnly("ab", '')      = false
     * StringUtils.containsOnly("abab", 'abc') = true
     * StringUtils.containsOnly("ab1", 'abc')  = false
     * StringUtils.containsOnly("abz", 'abc')  = false
     * </pre>
     *
     * @param cs    the String to check, may be null
     * @param valid an array of valid chars, may be null
     * @return true if it only contains valid chars and is non-null
     * @since 3.0 Changed signature from containsOnly(String, char[]) to
     * containsOnly(CharSequence, char...)
     */
    public static boolean containsOnly(CharSequence cs, char... valid) {
        // All these pre-checks are to maintain API with an older version
        if (valid == null || cs == null) {
            return false;
        }
        if (cs.length() == 0) {
            return true;
        }
        if (valid.length == 0) {
            return false;
        }
        return indexOfAnyBut(cs, valid) == INDEX_NOT_FOUND;
    }

    /**
     * <p>
     * Checks if the CharSequence contains only certain characters.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code false}. A {@code null}
     * valid character String will return {@code false}. An empty String
     * (length()=0) always returns {@code true}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.containsOnly(null, *)       = false
     * StringUtils.containsOnly(*, null)       = false
     * StringUtils.containsOnly("", *)         = true
     * StringUtils.containsOnly("ab", "")      = false
     * StringUtils.containsOnly("abab", "abc") = true
     * StringUtils.containsOnly("ab1", "abc")  = false
     * StringUtils.containsOnly("abz", "abc")  = false
     * </pre>
     *
     * @param cs         the CharSequence to check, may be null
     * @param validChars a String of valid chars, may be null
     * @return true if it only contains valid chars and is non-null
     * @since 3.0 Changed signature from containsOnly(String, String) to
     * containsOnly(CharSequence, String)
     */
    public static boolean containsOnly(CharSequence cs, String validChars) {
        if (cs == null || validChars == null) {
            return false;
        }
        return containsOnly(cs, validChars.toCharArray());
    }

    /**
     * <p>
     * Checks that the CharSequence does not contain certain characters.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code true}. A {@code null}
     * invalid character array will return {@code true}. An empty CharSequence
     * (length()=0) always returns true.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.containsNone(null, *)       = true
     * StringUtils.containsNone(*, null)       = true
     * StringUtils.containsNone("", *)         = true
     * StringUtils.containsNone("ab", '')      = true
     * StringUtils.containsNone("abab", 'xyz') = true
     * StringUtils.containsNone("ab1", 'xyz')  = true
     * StringUtils.containsNone("abz", 'xyz')  = false
     * </pre>
     *
     * @param cs          the CharSequence to check, may be null
     * @param searchChars an array of invalid chars, may be null
     * @return true if it contains none of the invalid chars, or is null
     * @since 3.0 Changed signature from containsNone(String, char[]) to
     * containsNone(CharSequence, char...)
     */
    public static boolean containsNone(CharSequence cs, char... searchChars) {
        if (cs == null || searchChars == null) {
            return true;
        }
        int csLen = cs.length();
        int csLast = csLen - 1;
        int searchLen = searchChars.length;
        int searchLast = searchLen - 1;
        for (int i = 0; i < csLen; i++) {
            char ch = cs.charAt(i);
            for (int j = 0; j < searchLen; j++) {
                if (searchChars[j] == ch) {
                    if (Character.isHighSurrogate(ch)) {
                        if (j == searchLast) {
                            // missing low surrogate, fine, like
                            // String.indexOf(String)
                            return false;
                        }
                        if (i < csLast && searchChars[j + 1] == cs.charAt(i + 1)) {
                            return false;
                        }
                    } else {
                        // ch is in the Basic Multilingual Plane
                        return false;
                    }
                }
            }
        }
        return true;
    }

    /**
     * <p>
     * Checks that the CharSequence does not contain certain characters.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code true}. A {@code null}
     * invalid character array will return {@code true}. An empty String ("")
     * always returns true.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.containsNone(null, *)       = true
     * StringUtils.containsNone(*, null)       = true
     * StringUtils.containsNone("", *)         = true
     * StringUtils.containsNone("ab", "")      = true
     * StringUtils.containsNone("abab", "xyz") = true
     * StringUtils.containsNone("ab1", "xyz")  = true
     * StringUtils.containsNone("abz", "xyz")  = false
     * </pre>
     *
     * @param cs           the CharSequence to check, may be null
     * @param invalidChars a String of invalid chars, may be null
     * @return true if it contains none of the invalid chars, or is null
     * @since 3.0 Changed signature from containsNone(String, String) to
     * containsNone(CharSequence, String)
     */
    public static boolean containsNone(CharSequence cs, String invalidChars) {
        if (cs == null || invalidChars == null) {
            return true;
        }
        return containsNone(cs, invalidChars.toCharArray());
    }

    /**
     * <p>
     * Find the first index of any of a set of potential substrings.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}. A {@code null} or
     * zero length search array will return {@code -1}. A {@code null} search
     * array entry will be ignored, but a search array containing "" will return
     * {@code 0} if {@code str} is not null. This method uses
     * {@link String#indexOf(String)} if possible.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOfAny(null, *)                     = -1
     * StringUtils.indexOfAny(*, null)                     = -1
     * StringUtils.indexOfAny(*, [])                       = -1
     * StringUtils.indexOfAny("zzabyycdxx", ["ab","cd"])   = 2
     * StringUtils.indexOfAny("zzabyycdxx", ["cd","ab"])   = 2
     * StringUtils.indexOfAny("zzabyycdxx", ["mn","op"])   = -1
     * StringUtils.indexOfAny("zzabyycdxx", ["zab","aby"]) = 1
     * StringUtils.indexOfAny("zzabyycdxx", [""])          = 0
     * StringUtils.indexOfAny("", [""])                    = 0
     * StringUtils.indexOfAny("", ["a"])                   = -1
     * </pre>
     *
     * @param str        the CharSequence to check, may be null
     * @param searchStrs the CharSequences to search for, may be null
     * @return the first index of any of the searchStrs in str, -1 if no match
     * @since 3.0 Changed signature from indexOfAny(String, String[]) to
     * indexOfAny(CharSequence, CharSequence...)
     */
    public static int indexOfAny(CharSequence str, CharSequence... searchStrs) {
        if (str == null || searchStrs == null) {
            return INDEX_NOT_FOUND;
        }
        int sz = searchStrs.length;

        // String's can't have a MAX_VALUEth index.
        int ret = Integer.MAX_VALUE;

        int tmp = 0;
        for (int i = 0; i < sz; i++) {
            CharSequence search = searchStrs[i];
            if (search == null) {
                continue;
            }
            tmp = CharSequenceUtils.indexOf(str, search, 0);
            if (tmp == INDEX_NOT_FOUND) {
                continue;
            }

            if (tmp < ret) {
                ret = tmp;
            }
        }

        return ret == Integer.MAX_VALUE ? INDEX_NOT_FOUND : ret;
    }

    /**
     * <p>
     * Find the latest index of any of a set of potential substrings.
     * </p>
     * <p/>
     * <p>
     * A {@code null} CharSequence will return {@code -1}. A {@code null} search
     * array will return {@code -1}. A {@code null} or zero length search array
     * entry will be ignored, but a search array containing "" will return the
     * length of {@code str} if {@code str} is not null. This method uses
     * {@link String#indexOf(String)} if possible
     * </p>
     * <p/>
     * <pre>
     * StringUtils.lastIndexOfAny(null, *)                   = -1
     * StringUtils.lastIndexOfAny(*, null)                   = -1
     * StringUtils.lastIndexOfAny(*, [])                     = -1
     * StringUtils.lastIndexOfAny(*, [null])                 = -1
     * StringUtils.lastIndexOfAny("zzabyycdxx", ["ab","cd"]) = 6
     * StringUtils.lastIndexOfAny("zzabyycdxx", ["cd","ab"]) = 6
     * StringUtils.lastIndexOfAny("zzabyycdxx", ["mn","op"]) = -1
     * StringUtils.lastIndexOfAny("zzabyycdxx", ["mn","op"]) = -1
     * StringUtils.lastIndexOfAny("zzabyycdxx", ["mn",""])   = 10
     * </pre>
     *
     * @param str        the CharSequence to check, may be null
     * @param searchStrs the CharSequences to search for, may be null
     * @return the last index of any of the CharSequences, -1 if no match
     * @since 3.0 Changed signature from lastIndexOfAny(String, String[]) to
     * lastIndexOfAny(CharSequence, CharSequence)
     */
    public static int lastIndexOfAny(CharSequence str, CharSequence... searchStrs) {
        if (str == null || searchStrs == null) {
            return INDEX_NOT_FOUND;
        }
        int sz = searchStrs.length;
        int ret = INDEX_NOT_FOUND;
        int tmp = 0;
        for (int i = 0; i < sz; i++) {
            CharSequence search = searchStrs[i];
            if (search == null) {
                continue;
            }
            tmp = CharSequenceUtils.lastIndexOf(str, search, str.length());
            if (tmp > ret) {
                ret = tmp;
            }
        }
        return ret;
    }

    /**
     * <p>
     * Gets a substring from the specified String avoiding exceptions.
     * </p>
     * <p/>
     * <p>
     * A negative start position can be used to start {@code n} characters from
     * the end of the String.
     * </p>
     * <p/>
     * <p>
     * A {@code null} String will return {@code null}. An empty ("") String will
     * return "".
     * </p>
     * <p/>
     * <pre>
     * StringUtils.substring(null, *)   = null
     * StringUtils.substring("", *)     = ""
     * StringUtils.substring("abc", 0)  = "abc"
     * StringUtils.substring("abc", 2)  = "c"
     * StringUtils.substring("abc", 4)  = ""
     * StringUtils.substring("abc", -2) = "bc"
     * StringUtils.substring("abc", -4) = "abc"
     * </pre>
     *
     * @param str      the String to get the substring from, may be null
     * @param startPos the position to start from, negative means count back from the
     *                 end of the String by this many characters
     * @return substring from start position, {@code null} if null String input
     */
    public static String substring(String str, int startPos) {
        if (str == null) {
            return null;
        }

        int start = startPos;
        // handle negatives, which means last n characters
        if (start < 0) {
            start = str.length() + start;
        }

        if (start < 0) {
            start = 0;
        }
        if (start > str.length()) {
            return EMPTY;
        }

        return str.substring(start);
    }

    /**
     * <p>
     * Gets a substring from the specified String avoiding exceptions.
     * </p>
     * <p/>
     * <p>
     * A negative start position can be used to start/end {@code n} characters
     * from the end of the String.
     * </p>
     * <p/>
     * <p>
     * The returned substring starts with the character in the {@code start}
     * position and ends before the {@code end} position. All position counting
     * is zero-based -- i.e., to start at the beginning of the string use
     * {@code start = 0}. Negative start and end positions can be used to
     * specify offsets relative to the end of the String.
     * </p>
     * <p/>
     * <p>
     * If {@code start} is not strictly to the left of {@code end}, "" is
     * returned.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.substring(null, *, *)    = null
     * StringUtils.substring("", * ,  *)    = "";
     * StringUtils.substring("abc", 0, 2)   = "ab"
     * StringUtils.substring("abc", 2, 0)   = ""
     * StringUtils.substring("abc", 2, 4)   = "c"
     * StringUtils.substring("abc", 4, 6)   = ""
     * StringUtils.substring("abc", 2, 2)   = ""
     * StringUtils.substring("abc", -2, -1) = "b"
     * StringUtils.substring("abc", -4, 2)  = "ab"
     * </pre>
     *
     * @param str      the String to get the substring from, may be null
     * @param startPos the position to start from, negative means count back from the
     *                 end of the String by this many characters
     * @param endPos   the position to end at (exclusive), negative means count back
     *                 from the end of the String by this many characters
     * @return substring from start position to end position, {@code null} if
     * null String input
     */
    public static String substring(String str, int startPos, int endPos) {
        if (str == null) {
            return null;
        }

        int start = startPos, end = endPos;
        // handle negatives
        if (end < 0) {
            end = str.length() + end;
        }
        if (start < 0) {
            start = str.length() + start;
        }

        // check length next
        if (end > str.length()) {
            end = str.length();
        }

        // if start is greater than end, return ""
        if (start > end) {
            return EMPTY;
        }

        if (start < 0) {
            start = 0;
        }
        if (end < 0) {
            end = 0;
        }

        return str.substring(start, end);
    }

    /**
     * <p>
     * Gets the leftmost {@code len} characters of a String.
     * </p>
     * <p/>
     * <p>
     * If {@code len} characters are not available, or the String is
     * {@code null}, the String will be returned without an exception. An empty
     * String is returned if len is negative.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.left(null, *)    = null
     * StringUtils.left(*, -ve)     = ""
     * StringUtils.left("", *)      = ""
     * StringUtils.left("abc", 0)   = ""
     * StringUtils.left("abc", 2)   = "ab"
     * StringUtils.left("abc", 4)   = "abc"
     * </pre>
     *
     * @param str the String to get the leftmost characters from, may be null
     * @param len the length of the required String
     * @return the leftmost characters, {@code null} if null String input
     */
    public static String left(String str, int len) {
        if (str == null) {
            return null;
        }
        if (len < 0) {
            return EMPTY;
        }
        if (str.length() <= len) {
            return str;
        }
        return str.substring(0, len);
    }

    /**
     * <p>
     * Gets the rightmost {@code len} characters of a String.
     * </p>
     * <p/>
     * <p>
     * If {@code len} characters are not available, or the String is
     * {@code null}, the String will be returned without an an exception. An
     * empty String is returned if len is negative.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.right(null, *)    = null
     * StringUtils.right(*, -ve)     = ""
     * StringUtils.right("", *)      = ""
     * StringUtils.right("abc", 0)   = ""
     * StringUtils.right("abc", 2)   = "bc"
     * StringUtils.right("abc", 4)   = "abc"
     * </pre>
     *
     * @param str the String to get the rightmost characters from, may be null
     * @param len the length of the required String
     * @return the rightmost characters, {@code null} if null String input
     */
    public static String right(String str, int len) {
        if (str == null) {
            return null;
        }
        if (len < 0) {
            return EMPTY;
        }
        if (str.length() <= len) {
            return str;
        }
        return str.substring(str.length() - len);
    }

    /**
     * <p>
     * Gets {@code len} characters from the middle of a String.
     * </p>
     * <p/>
     * <p>
     * If {@code len} characters are not available, the remainder of the String
     * will be returned without an exception. If the String is {@code null},
     * {@code null} will be returned. An empty String is returned if len is
     * negative or exceeds the length of {@code str}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.mid(null, *, *)    = null
     * StringUtils.mid(*, *, -ve)     = ""
     * StringUtils.mid("", 0, *)      = ""
     * StringUtils.mid("abc", 0, 2)   = "ab"
     * StringUtils.mid("abc", 0, 4)   = "abc"
     * StringUtils.mid("abc", 2, 4)   = "c"
     * StringUtils.mid("abc", 4, 2)   = ""
     * StringUtils.mid("abc", -2, 2)  = "ab"
     * </pre>
     *
     * @param str      the String to get the characters from, may be null
     * @param startPos the position to start from, negative treated as zero
     * @param len      the length of the required String
     * @return the middle characters, {@code null} if null String input
     */
    public static String mid(String str, int startPos, int len) {
        if (str == null) {
            return null;
        }
        int pos = startPos;
        if (len < 0 || pos > str.length()) {
            return EMPTY;
        }
        if (pos < 0) {
            pos = 0;
        }
        if (str.length() <= pos + len) {
            return str.substring(pos);
        }
        return str.substring(pos, pos + len);
    }

    /**
     * <p>
     * Gets the substring before the first occurrence of a separator. The
     * separator is not returned.
     * </p>
     * <p/>
     * <p>
     * A {@code null} string input will return {@code null}. An empty ("")
     * string input will return the empty string. A {@code null} separator will
     * return the input string.
     * </p>
     * <p/>
     * <p>
     * If nothing is found, the string input is returned.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.substringBefore(null, *)      = null
     * StringUtils.substringBefore("", *)        = ""
     * StringUtils.substringBefore("abc", "a")   = ""
     * StringUtils.substringBefore("abcba", "b") = "a"
     * StringUtils.substringBefore("abc", "c")   = "ab"
     * StringUtils.substringBefore("abc", "d")   = "abc"
     * StringUtils.substringBefore("abc", "")    = ""
     * StringUtils.substringBefore("abc", null)  = "abc"
     * </pre>
     *
     * @param str       the String to get a substring from, may be null
     * @param separator the String to search for, may be null
     * @return the substring before the first occurrence of the separator,
     * {@code null} if null String input
     * @since 2.0
     */
    public static String substringBefore(String str, String separator) {
        if (isEmpty(str) || separator == null) {
            return str;
        }
        if (separator.length() == 0) {
            return EMPTY;
        }
        int pos = str.indexOf(separator);
        if (pos == INDEX_NOT_FOUND) {
            return str;
        }
        return str.substring(0, pos);
    }

    /**
     * <p>
     * Gets the substring after the first occurrence of a separator. The
     * separator is not returned.
     * </p>
     * <p/>
     * <p>
     * A {@code null} string input will return {@code null}. An empty ("")
     * string input will return the empty string. A {@code null} separator will
     * return the empty string if the input string is not {@code null}.
     * </p>
     * <p/>
     * <p>
     * If nothing is found, the empty string is returned.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.substringAfter(null, *)      = null
     * StringUtils.substringAfter("", *)        = ""
     * StringUtils.substringAfter(*, null)      = ""
     * StringUtils.substringAfter("abc", "a")   = "bc"
     * StringUtils.substringAfter("abcba", "b") = "cba"
     * StringUtils.substringAfter("abc", "c")   = ""
     * StringUtils.substringAfter("abc", "d")   = ""
     * StringUtils.substringAfter("abc", "")    = "abc"
     * </pre>
     *
     * @param str       the String to get a substring from, may be null
     * @param separator the String to search for, may be null
     * @return the substring after the first occurrence of the separator,
     * {@code null} if null String input
     * @since 2.0
     */
    public static String substringAfter(String str, String separator) {
        if (isEmpty(str)) {
            return str;
        }
        if (separator == null) {
            return EMPTY;
        }
        int pos = str.indexOf(separator);
        if (pos == INDEX_NOT_FOUND) {
            return EMPTY;
        }
        return str.substring(pos + separator.length());
    }

    /**
     * <p>
     * Gets the substring before the last occurrence of a separator. The
     * separator is not returned.
     * </p>
     * <p/>
     * <p>
     * A {@code null} string input will return {@code null}. An empty ("")
     * string input will return the empty string. An empty or {@code null}
     * separator will return the input string.
     * </p>
     * <p/>
     * <p>
     * If nothing is found, the string input is returned.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.substringBeforeLast(null, *)      = null
     * StringUtils.substringBeforeLast("", *)        = ""
     * StringUtils.substringBeforeLast("abcba", "b") = "abc"
     * StringUtils.substringBeforeLast("abc", "c")   = "ab"
     * StringUtils.substringBeforeLast("a", "a")     = ""
     * StringUtils.substringBeforeLast("a", "z")     = "a"
     * StringUtils.substringBeforeLast("a", null)    = "a"
     * StringUtils.substringBeforeLast("a", "")      = "a"
     * </pre>
     *
     * @param str       the String to get a substring from, may be null
     * @param separator the String to search for, may be null
     * @return the substring before the last occurrence of the separator,
     * {@code null} if null String input
     * @since 2.0
     */
    public static String substringBeforeLast(String str, String separator) {
        if (isEmpty(str) || isEmpty(separator)) {
            return str;
        }
        int pos = str.lastIndexOf(separator);
        if (pos == INDEX_NOT_FOUND) {
            return str;
        }
        return str.substring(0, pos);
    }

    /**
     * <p>
     * Gets the substring after the last occurrence of a separator. The
     * separator is not returned.
     * </p>
     * <p/>
     * <p>
     * A {@code null} string input will return {@code null}. An empty ("")
     * string input will return the empty string. An empty or {@code null}
     * separator will return the empty string if the input string is not
     * {@code null}.
     * </p>
     * <p/>
     * <p>
     * If nothing is found, the empty string is returned.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.substringAfterLast(null, *)      = null
     * StringUtils.substringAfterLast("", *)        = ""
     * StringUtils.substringAfterLast(*, "")        = ""
     * StringUtils.substringAfterLast(*, null)      = ""
     * StringUtils.substringAfterLast("abc", "a")   = "bc"
     * StringUtils.substringAfterLast("abcba", "b") = "a"
     * StringUtils.substringAfterLast("abc", "c")   = ""
     * StringUtils.substringAfterLast("a", "a")     = ""
     * StringUtils.substringAfterLast("a", "z")     = ""
     * </pre>
     *
     * @param str       the String to get a substring from, may be null
     * @param separator the String to search for, may be null
     * @return the substring after the last occurrence of the separator,
     * {@code null} if null String input
     * @since 2.0
     */
    public static String substringAfterLast(String str, String separator) {
        if (isEmpty(str)) {
            return str;
        }
        if (isEmpty(separator)) {
            return EMPTY;
        }
        int pos = str.lastIndexOf(separator);
        if (pos == INDEX_NOT_FOUND || pos == str.length() - separator.length()) {
            return EMPTY;
        }
        return str.substring(pos + separator.length());
    }

    /**
     * <p>
     * Gets the String that is nested in between two instances of the same
     * String.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. A {@code null} tag
     * returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.substringBetween(null, *)            = null
     * StringUtils.substringBetween("", "")             = ""
     * StringUtils.substringBetween("", "tag")          = null
     * StringUtils.substringBetween("tagabctag", null)  = null
     * StringUtils.substringBetween("tagabctag", "")    = ""
     * StringUtils.substringBetween("tagabctag", "tag") = "abc"
     * </pre>
     *
     * @param str the String containing the substring, may be null
     * @param tag the String before and after the substring, may be null
     * @return the substring, {@code null} if no match
     * @since 2.0
     */
    public static String substringBetween(String str, String tag) {
        return substringBetween(str, tag, tag);
    }

    /**
     * <p>
     * Gets the String that is nested in between two Strings. Only the first
     * match is returned.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. A {@code null}
     * open/close returns {@code null} (no match). An empty ("") open and close
     * returns an empty string.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.substringBetween("wx[b]yz", "[", "]") = "b"
     * StringUtils.substringBetween(null, *, *)          = null
     * StringUtils.substringBetween(*, null, *)          = null
     * StringUtils.substringBetween(*, *, null)          = null
     * StringUtils.substringBetween("", "", "")          = ""
     * StringUtils.substringBetween("", "", "]")         = null
     * StringUtils.substringBetween("", "[", "]")        = null
     * StringUtils.substringBetween("yabcz", "", "")     = ""
     * StringUtils.substringBetween("yabcz", "y", "z")   = "abc"
     * StringUtils.substringBetween("yabczyabcz", "y", "z")   = "abc"
     * </pre>
     *
     * @param str   the String containing the substring, may be null
     * @param open  the String before the substring, may be null
     * @param close the String after the substring, may be null
     * @return the substring, {@code null} if no match
     * @since 2.0
     */
    public static String substringBetween(String str, String open, String close) {
        if (str == null || open == null || close == null) {
            return null;
        }
        int start = str.indexOf(open);
        if (start != INDEX_NOT_FOUND) {
            int end = str.indexOf(close, start + open.length());
            if (end != INDEX_NOT_FOUND) {
                return str.substring(start + open.length(), end);
            }
        }
        return null;
    }

    /**
     * <p>
     * Searches a String for substrings delimited by a start and end tag,
     * returning all matching substrings in an array.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. A {@code null}
     * open/close returns {@code null} (no match). An empty ("") open/close
     * returns {@code null} (no match).
     * </p>
     * <p/>
     * <pre>
     * StringUtils.substringsBetween("[a][b][c]", "[", "]") = ["a","b","c"]
     * StringUtils.substringsBetween(null, *, *)            = null
     * StringUtils.substringsBetween(*, null, *)            = null
     * StringUtils.substringsBetween(*, *, null)            = null
     * StringUtils.substringsBetween("", "[", "]")          = []
     * </pre>
     *
     * @param str   the String containing the substrings, null returns null, empty
     *              returns empty
     * @param open  the String identifying the start of the substring, empty
     *              returns null
     * @param close the String identifying the end of the substring, empty returns
     *              null
     * @return a String Array of substrings, or {@code null} if no match
     * @since 2.3
     */
    public static String[] substringsBetween(String str, String open, String close) {
        if (str == null || isEmpty(open) || isEmpty(close)) {
            return new String[0];
        }
        int strLen = str.length();
        if (strLen == 0) {
            return new String[0];
        }
        int closeLen = close.length();
        int openLen = open.length();
        List<String> list = new ArrayList<>();
        int pos = 0;
        while (pos < strLen - closeLen) {
            int start = str.indexOf(open, pos);
            if (start < 0) {
                break;
            }
            start += openLen;
            int end = str.indexOf(close, start);
            if (end < 0) {
                break;
            }
            list.add(str.substring(start, end));
            pos = end + closeLen;
        }
        if (list.isEmpty()) {
            return new String[0];
        }
        return list.toArray(new String[list.size()]);
    }

    /**
     * <p>
     * Splits the provided text into an array, using whitespace as the
     * separator. Whitespace is defined by {@link Character#isWhitespace(char)}.
     * </p>
     * <p/>
     * <p>
     * The separator is not included in the returned String array. Adjacent
     * separators are treated as one separator. For more control over the split
     * use the StrTokenizer class.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.split(null)       = null
     * StringUtils.split("")         = []
     * StringUtils.split("abc def")  = ["abc", "def"]
     * StringUtils.split("abc  def") = ["abc", "def"]
     * StringUtils.split(" abc ")    = ["abc"]
     * </pre>
     *
     * @param str the String to parse, may be null
     * @return an array of parsed Strings, {@code null} if null String input
     */
    public static String[] split(String str) {
        return split(str, null, -1);
    }

    /**
     * <p>
     * Splits the provided text into an array, separator specified. This is an
     * alternative to using StringTokenizer.
     * </p>
     * <p/>
     * <p>
     * The separator is not included in the returned String array. Adjacent
     * separators are treated as one separator. For more control over the split
     * use the StrTokenizer class.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.split(null, *)         = null
     * StringUtils.split("", *)           = []
     * StringUtils.split("a.b.c", '.')    = ["a", "b", "c"]
     * StringUtils.split("a..b.c", '.')   = ["a", "b", "c"]
     * StringUtils.split("a:b:c", '.')    = ["a:b:c"]
     * StringUtils.split("a b c", ' ')    = ["a", "b", "c"]
     * </pre>
     *
     * @param str           the String to parse, may be null
     * @param separatorChar the character used as the delimiter
     * @return an array of parsed Strings, {@code null} if null String input
     * @since 2.0
     */
    public static String[] split(String str, char separatorChar) {
        return splitWorker(str, separatorChar, false);
    }

    /**
     * <p>
     * Splits the provided text into an array, separators specified. This is an
     * alternative to using StringTokenizer.
     * </p>
     * <p/>
     * <p>
     * The separator is not included in the returned String array. Adjacent
     * separators are treated as one separator. For more control over the split
     * use the StrTokenizer class.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. A {@code null}
     * separatorChars splits on whitespace.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.split(null, *)         = null
     * StringUtils.split("", *)           = []
     * StringUtils.split("abc def", null) = ["abc", "def"]
     * StringUtils.split("abc def", " ")  = ["abc", "def"]
     * StringUtils.split("abc  def", " ") = ["abc", "def"]
     * StringUtils.split("ab:cd:ef", ":") = ["ab", "cd", "ef"]
     * </pre>
     *
     * @param str            the String to parse, may be null
     * @param separatorChars the characters used as the delimiters, {@code null} splits on
     *                       whitespace
     * @return an array of parsed Strings, {@code null} if null String input
     */
    public static String[] split(String str, String separatorChars) {
        return splitWorker(str, separatorChars, -1, false);
    }

    /**
     * <p>
     * Splits the provided text into an array with a maximum length, separators
     * specified.
     * </p>
     * <p/>
     * <p>
     * The separator is not included in the returned String array. Adjacent
     * separators are treated as one separator.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. A {@code null}
     * separatorChars splits on whitespace.
     * </p>
     * <p/>
     * <p>
     * If more than {@code max} delimited substrings are found, the last
     * returned string includes all characters after the first {@code max - 1}
     * returned strings (including separator characters).
     * </p>
     * <p/>
     * <pre>
     * StringUtils.split(null, *, *)            = null
     * StringUtils.split("", *, *)              = []
     * StringUtils.split("ab de fg", null, 0)   = ["ab", "cd", "ef"]
     * StringUtils.split("ab   de fg", null, 0) = ["ab", "cd", "ef"]
     * StringUtils.split("ab:cd:ef", ":", 0)    = ["ab", "cd", "ef"]
     * StringUtils.split("ab:cd:ef", ":", 2)    = ["ab", "cd:ef"]
     * </pre>
     *
     * @param str            the String to parse, may be null
     * @param separatorChars the characters used as the delimiters, {@code null} splits on
     *                       whitespace
     * @param max            the maximum number of elements to include in the array. A zero
     *                       or negative value implies no limit
     * @return an array of parsed Strings, {@code null} if null String input
     */
    public static String[] split(String str, String separatorChars, int max) {
        return splitWorker(str, separatorChars, max, false);
    }

    /**
     * <p>
     * Splits the provided text into an array, separator string specified.
     * </p>
     * <p/>
     * <p>
     * The separator(s) will not be included in the returned String array.
     * Adjacent separators are treated as one separator.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. A {@code null}
     * separator splits on whitespace.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.splitByWholeSeparator(null, *)               = null
     * StringUtils.splitByWholeSeparator("", *)                 = []
     * StringUtils.splitByWholeSeparator("ab de fg", null)      = ["ab", "de", "fg"]
     * StringUtils.splitByWholeSeparator("ab   de fg", null)    = ["ab", "de", "fg"]
     * StringUtils.splitByWholeSeparator("ab:cd:ef", ":")       = ["ab", "cd", "ef"]
     * StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-") = ["ab", "cd", "ef"]
     * </pre>
     *
     * @param str       the String to parse, may be null
     * @param separator String containing the String to be used as a delimiter,
     *                  {@code null} splits on whitespace
     * @return an array of parsed Strings, {@code null} if null String was input
     */
    public static String[] splitByWholeSeparator(String str, String separator) {
        return splitByWholeSeparatorWorker(str, separator, -1, false);
    }

    /**
     * <p>
     * Splits the provided text into an array, separator string specified.
     * Returns a maximum of {@code max} substrings.
     * </p>
     * <p/>
     * <p>
     * The separator(s) will not be included in the returned String array.
     * Adjacent separators are treated as one separator.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. A {@code null}
     * separator splits on whitespace.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.splitByWholeSeparator(null, *, *)               = null
     * StringUtils.splitByWholeSeparator("", *, *)                 = []
     * StringUtils.splitByWholeSeparator("ab de fg", null, 0)      = ["ab", "de", "fg"]
     * StringUtils.splitByWholeSeparator("ab   de fg", null, 0)    = ["ab", "de", "fg"]
     * StringUtils.splitByWholeSeparator("ab:cd:ef", ":", 2)       = ["ab", "cd:ef"]
     * StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-", 5) = ["ab", "cd", "ef"]
     * StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-", 2) = ["ab", "cd-!-ef"]
     * </pre>
     *
     * @param str       the String to parse, may be null
     * @param separator String containing the String to be used as a delimiter,
     *                  {@code null} splits on whitespace
     * @param max       the maximum number of elements to include in the returned
     *                  array. A zero or negative value implies no limit.
     * @return an array of parsed Strings, {@code null} if null String was input
     */
    public static String[] splitByWholeSeparator(String str, String separator, int max) {
        return splitByWholeSeparatorWorker(str, separator, max, false);
    }

    /**
     * <p>
     * Splits the provided text into an array, separator string specified.
     * </p>
     * <p/>
     * <p>
     * The separator is not included in the returned String array. Adjacent
     * separators are treated as separators for empty tokens. For more control
     * over the split use the StrTokenizer class.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. A {@code null}
     * separator splits on whitespace.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.splitByWholeSeparatorPreserveAllTokens(null, *)               = null
     * StringUtils.splitByWholeSeparatorPreserveAllTokens("", *)                 = []
     * StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null)      = ["ab", "de", "fg"]
     * StringUtils.splitByWholeSeparatorPreserveAllTokens("ab   de fg", null)    = ["ab", "", "", "de", "fg"]
     * StringUtils.splitByWholeSeparatorPreserveAllTokens("ab:cd:ef", ":")       = ["ab", "cd", "ef"]
     * StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-") = ["ab", "cd", "ef"]
     * </pre>
     *
     * @param str       the String to parse, may be null
     * @param separator String containing the String to be used as a delimiter,
     *                  {@code null} splits on whitespace
     * @return an array of parsed Strings, {@code null} if null String was input
     * @since 2.4
     */
    public static String[] splitByWholeSeparatorPreserveAllTokens(String str, String separator) {
        return splitByWholeSeparatorWorker(str, separator, -1, true);
    }

    /**
     * <p>
     * Splits the provided text into an array, separator string specified.
     * Returns a maximum of {@code max} substrings.
     * </p>
     * <p/>
     * <p>
     * The separator is not included in the returned String array. Adjacent
     * separators are treated as separators for empty tokens. For more control
     * over the split use the StrTokenizer class.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. A {@code null}
     * separator splits on whitespace.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.splitByWholeSeparatorPreserveAllTokens(null, *, *)               = null
     * StringUtils.splitByWholeSeparatorPreserveAllTokens("", *, *)                 = []
     * StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null, 0)      = ["ab", "de", "fg"]
     * StringUtils.splitByWholeSeparatorPreserveAllTokens("ab   de fg", null, 0)    = ["ab", "", "", "de", "fg"]
     * StringUtils.splitByWholeSeparatorPreserveAllTokens("ab:cd:ef", ":", 2)       = ["ab", "cd:ef"]
     * StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-", 5) = ["ab", "cd", "ef"]
     * StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-", 2) = ["ab", "cd-!-ef"]
     * </pre>
     *
     * @param str       the String to parse, may be null
     * @param separator String containing the String to be used as a delimiter,
     *                  {@code null} splits on whitespace
     * @param max       the maximum number of elements to include in the returned
     *                  array. A zero or negative value implies no limit.
     * @return an array of parsed Strings, {@code null} if null String was input
     * @since 2.4
     */
    public static String[] splitByWholeSeparatorPreserveAllTokens(String str, String separator, int max) {
        return splitByWholeSeparatorWorker(str, separator, max, true);
    }

    /**
     * Performs the logic for the {@code splitByWholeSeparatorPreserveAllTokens}
     * methods.
     *
     * @param str               the String to parse, may be {@code null}
     * @param separator         String containing the String to be used as a delimiter,
     *                          {@code null} splits on whitespace
     * @param max               the maximum number of elements to include in the returned
     *                          array. A zero or negative value implies no limit.
     * @param preserveAllTokens if {@code true}, adjacent separators are treated as empty
     *                          token separators; if {@code false}, adjacent separators are
     *                          treated as one separator.
     * @return an array of parsed Strings, {@code null} if null String input
     * @since 2.4
     */
    private static String[] splitByWholeSeparatorWorker(String str, String separator, int max,
            boolean preserveAllTokens) {
        if (str == null) {
            return new String[0];
        }

        int len = str.length();

        if (len == 0) {
            return EMPTY_STRING_ARRAY;
        }

        if (separator == null || EMPTY.equals(separator)) {
            // Split on whitespace.
            return splitWorker(str, null, max, preserveAllTokens);
        }

        int separatorLength = separator.length();

        ArrayList<String> substrings = new ArrayList<String>();
        int numberOfSubstrings = 0;
        int beg = 0;
        int end = 0;
        while (end < len) {
            end = str.indexOf(separator, beg);

            if (end > -1) {
                if (end > beg) {
                    numberOfSubstrings += 1;

                    if (numberOfSubstrings == max) {
                        end = len;
                        substrings.add(str.substring(beg));
                    } else {
                        // The following is OK, because String.substring( beg,
                        // end ) excludes
                        // the character at the position 'end'.
                        substrings.add(str.substring(beg, end));

                        // Set the starting point for the next search.
                        // The following is equivalent to beg = end +
                        // (separatorLength - 1) + 1,
                        // which is the right calculation:
                        beg = end + separatorLength;
                    }
                } else {
                    // We found a consecutive occurrence of the separator, so
                    // skip it.
                    if (preserveAllTokens) {
                        numberOfSubstrings += 1;
                        if (numberOfSubstrings == max) {
                            end = len;
                            substrings.add(str.substring(beg));
                        } else {
                            substrings.add(EMPTY);
                        }
                    }
                    beg = end + separatorLength;
                }
            } else {
                // String.substring( beg ) goes from 'beg' to the end of the
                // String.
                substrings.add(str.substring(beg));
                end = len;
            }
        }

        return substrings.toArray(new String[substrings.size()]);
    }

    /**
     * <p>
     * Splits the provided text into an array, using whitespace as the
     * separator, preserving all tokens, including empty tokens created by
     * adjacent separators. This is an alternative to using StringTokenizer.
     * Whitespace is defined by {@link Character#isWhitespace(char)}.
     * </p>
     * <p/>
     * <p>
     * The separator is not included in the returned String array. Adjacent
     * separators are treated as separators for empty tokens. For more control
     * over the split use the StrTokenizer class.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.splitPreserveAllTokens(null)       = null
     * StringUtils.splitPreserveAllTokens("")         = []
     * StringUtils.splitPreserveAllTokens("abc def")  = ["abc", "def"]
     * StringUtils.splitPreserveAllTokens("abc  def") = ["abc", "", "def"]
     * StringUtils.splitPreserveAllTokens(" abc ")    = ["", "abc", ""]
     * </pre>
     *
     * @param str the String to parse, may be {@code null}
     * @return an array of parsed Strings, {@code null} if null String input
     * @since 2.1
     */
    public static String[] splitPreserveAllTokens(String str) {
        return splitWorker(str, null, -1, true);
    }

    /**
     * <p>
     * Splits the provided text into an array, separator specified, preserving
     * all tokens, including empty tokens created by adjacent separators. This
     * is an alternative to using StringTokenizer.
     * </p>
     * <p/>
     * <p>
     * The separator is not included in the returned String array. Adjacent
     * separators are treated as separators for empty tokens. For more control
     * over the split use the StrTokenizer class.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.splitPreserveAllTokens(null, *)         = null
     * StringUtils.splitPreserveAllTokens("", *)           = []
     * StringUtils.splitPreserveAllTokens("a.b.c", '.')    = ["a", "b", "c"]
     * StringUtils.splitPreserveAllTokens("a..b.c", '.')   = ["a", "", "b", "c"]
     * StringUtils.splitPreserveAllTokens("a:b:c", '.')    = ["a:b:c"]
     * StringUtils.splitPreserveAllTokens("a\tb\nc", null) = ["a", "b", "c"]
     * StringUtils.splitPreserveAllTokens("a b c", ' ')    = ["a", "b", "c"]
     * StringUtils.splitPreserveAllTokens("a b c ", ' ')   = ["a", "b", "c", ""]
     * StringUtils.splitPreserveAllTokens("a b c  ", ' ')   = ["a", "b", "c", "", ""]
     * StringUtils.splitPreserveAllTokens(" a b c", ' ')   = ["", a", "b", "c"]
     * StringUtils.splitPreserveAllTokens("  a b c", ' ')  = ["", "", a", "b", "c"]
     * StringUtils.splitPreserveAllTokens(" a b c ", ' ')  = ["", a", "b", "c", ""]
     * </pre>
     *
     * @param str           the String to parse, may be {@code null}
     * @param separatorChar the character used as the delimiter, {@code null} splits on
     *                      whitespace
     * @return an array of parsed Strings, {@code null} if null String input
     * @since 2.1
     */
    public static String[] splitPreserveAllTokens(String str, char separatorChar) {
        return splitWorker(str, separatorChar, true);
    }

    /**
     * Performs the logic for the {@code split} and
     * {@code splitPreserveAllTokens} methods that do not return a maximum array
     * length.
     *
     * @param str               the String to parse, may be {@code null}
     * @param separatorChar     the separate character
     * @param preserveAllTokens if {@code true}, adjacent separators are treated as empty
     *                          token separators; if {@code false}, adjacent separators are
     *                          treated as one separator.
     * @return an array of parsed Strings, {@code null} if null String input
     */
    private static String[] splitWorker(String str, char separatorChar, boolean preserveAllTokens) {
        // Performance tuned for 2.0 (JDK1.4)

        if (str == null) {
            return new String[0];
        }
        int len = str.length();
        if (len == 0) {
            return EMPTY_STRING_ARRAY;
        }
        List<String> list = new ArrayList<String>();
        int i = 0, start = 0;
        boolean match = false;
        boolean lastMatch = false;
        while (i < len) {
            if (str.charAt(i) == separatorChar) {
                if (match || preserveAllTokens) {
                    list.add(str.substring(start, i));
                    match = false;
                    lastMatch = true;
                }
                start = ++i;
                continue;
            }
            lastMatch = false;
            match = true;
            i++;
        }
        if (match || preserveAllTokens && lastMatch) {
            list.add(str.substring(start, i));
        }
        return list.toArray(new String[list.size()]);
    }

    /**
     * <p>
     * Splits the provided text into an array, separators specified, preserving
     * all tokens, including empty tokens created by adjacent separators. This
     * is an alternative to using StringTokenizer.
     * </p>
     * <p/>
     * <p>
     * The separator is not included in the returned String array. Adjacent
     * separators are treated as separators for empty tokens. For more control
     * over the split use the StrTokenizer class.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. A {@code null}
     * separatorChars splits on whitespace.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.splitPreserveAllTokens(null, *)           = null
     * StringUtils.splitPreserveAllTokens("", *)             = []
     * StringUtils.splitPreserveAllTokens("abc def", null)   = ["abc", "def"]
     * StringUtils.splitPreserveAllTokens("abc def", " ")    = ["abc", "def"]
     * StringUtils.splitPreserveAllTokens("abc  def", " ")   = ["abc", "", def"]
     * StringUtils.splitPreserveAllTokens("ab:cd:ef", ":")   = ["ab", "cd", "ef"]
     * StringUtils.splitPreserveAllTokens("ab:cd:ef:", ":")  = ["ab", "cd", "ef", ""]
     * StringUtils.splitPreserveAllTokens("ab:cd:ef::", ":") = ["ab", "cd", "ef", "", ""]
     * StringUtils.splitPreserveAllTokens("ab::cd:ef", ":")  = ["ab", "", cd", "ef"]
     * StringUtils.splitPreserveAllTokens(":cd:ef", ":")     = ["", cd", "ef"]
     * StringUtils.splitPreserveAllTokens("::cd:ef", ":")    = ["", "", cd", "ef"]
     * StringUtils.splitPreserveAllTokens(":cd:ef:", ":")    = ["", cd", "ef", ""]
     * </pre>
     *
     * @param str            the String to parse, may be {@code null}
     * @param separatorChars the characters used as the delimiters, {@code null} splits on
     *                       whitespace
     * @return an array of parsed Strings, {@code null} if null String input
     * @since 2.1
     */
    public static String[] splitPreserveAllTokens(String str, String separatorChars) {
        return splitWorker(str, separatorChars, -1, true);
    }

    /**
     * <p>
     * Splits the provided text into an array with a maximum length, separators
     * specified, preserving all tokens, including empty tokens created by
     * adjacent separators.
     * </p>
     * <p/>
     * <p>
     * The separator is not included in the returned String array. Adjacent
     * separators are treated as separators for empty tokens. Adjacent
     * separators are treated as one separator.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}. A {@code null}
     * separatorChars splits on whitespace.
     * </p>
     * <p/>
     * <p>
     * If more than {@code max} delimited substrings are found, the last
     * returned string includes all characters after the first {@code max - 1}
     * returned strings (including separator characters).
     * </p>
     * <p/>
     * <pre>
     * StringUtils.splitPreserveAllTokens(null, *, *)            = null
     * StringUtils.splitPreserveAllTokens("", *, *)              = []
     * StringUtils.splitPreserveAllTokens("ab de fg", null, 0)   = ["ab", "cd", "ef"]
     * StringUtils.splitPreserveAllTokens("ab   de fg", null, 0) = ["ab", "cd", "ef"]
     * StringUtils.splitPreserveAllTokens("ab:cd:ef", ":", 0)    = ["ab", "cd", "ef"]
     * StringUtils.splitPreserveAllTokens("ab:cd:ef", ":", 2)    = ["ab", "cd:ef"]
     * StringUtils.splitPreserveAllTokens("ab   de fg", null, 2) = ["ab", "  de fg"]
     * StringUtils.splitPreserveAllTokens("ab   de fg", null, 3) = ["ab", "", " de fg"]
     * StringUtils.splitPreserveAllTokens("ab   de fg", null, 4) = ["ab", "", "", "de fg"]
     * </pre>
     *
     * @param str            the String to parse, may be {@code null}
     * @param separatorChars the characters used as the delimiters, {@code null} splits on
     *                       whitespace
     * @param max            the maximum number of elements to include in the array. A zero
     *                       or negative value implies no limit
     * @return an array of parsed Strings, {@code null} if null String input
     * @since 2.1
     */
    public static String[] splitPreserveAllTokens(String str, String separatorChars, int max) {
        return splitWorker(str, separatorChars, max, true);
    }

    /**
     * Performs the logic for the {@code split} and
     * {@code splitPreserveAllTokens} methods that return a maximum array
     * length.
     *
     * @param str               the String to parse, may be {@code null}
     * @param separatorChars    the separate character
     * @param max               the maximum number of elements to include in the array. A zero
     *                          or negative value implies no limit.
     * @param preserveAllTokens if {@code true}, adjacent separators are treated as empty
     *                          token separators; if {@code false}, adjacent separators are
     *                          treated as one separator.
     * @return an array of parsed Strings, {@code null} if null String input
     */
    private static String[] splitWorker(String str, String separatorChars, int max, boolean preserveAllTokens) {
        // Performance tuned for 2.0 (JDK1.4)
        // Direct code is quicker than StringTokenizer.
        // Also, StringTokenizer uses isSpace() not isWhitespace()

        if (str == null) {
            return new String[0];
        }
        int len = str.length();
        if (len == 0) {
            return EMPTY_STRING_ARRAY;
        }
        List<String> list = new ArrayList<String>();
        int sizePlus1 = 1;
        int i = 0, start = 0;
        boolean match = false;
        boolean lastMatch = false;
        if (separatorChars == null) {
            // Null separator means use whitespace
            while (i < len) {
                if (Character.isWhitespace(str.charAt(i))) {
                    if (match || preserveAllTokens) {
                        lastMatch = true;
                        if (sizePlus1++ == max) {
                            i = len;
                            lastMatch = false;
                        }
                        list.add(str.substring(start, i));
                        match = false;
                    }
                    start = ++i;
                    continue;
                }
                lastMatch = false;
                match = true;
                i++;
            }
        } else if (separatorChars.length() == 1) {
            // Optimise 1 character case
            char sep = separatorChars.charAt(0);
            while (i < len) {
                if (str.charAt(i) == sep) {
                    if (match || preserveAllTokens) {
                        lastMatch = true;
                        if (sizePlus1++ == max) {
                            i = len;
                            lastMatch = false;
                        }
                        list.add(str.substring(start, i));
                        match = false;
                    }
                    start = ++i;
                    continue;
                }
                lastMatch = false;
                match = true;
                i++;
            }
        } else {
            // standard case
            while (i < len) {
                if (separatorChars.indexOf(str.charAt(i)) >= 0) {
                    if (match || preserveAllTokens) {
                        lastMatch = true;
                        if (sizePlus1++ == max) {
                            i = len;
                            lastMatch = false;
                        }
                        list.add(str.substring(start, i));
                        match = false;
                    }
                    start = ++i;
                    continue;
                }
                lastMatch = false;
                match = true;
                i++;
            }
        }
        if (match || preserveAllTokens && lastMatch) {
            list.add(str.substring(start, i));
        }
        return list.toArray(new String[list.size()]);
    }

    /**
     * <p/>
     * Splits a String by Character type as returned by
     * {@code java.lang.Character.getType(char)}. Groups of contiguous
     * characters of the same type are returned as complete tokens.
     * <p/>
     * <pre>
     * StringUtils.splitByCharacterType(null)         = null
     * StringUtils.splitByCharacterType("")           = []
     * StringUtils.splitByCharacterType("ab de fg")   = ["ab", " ", "de", " ", "fg"]
     * StringUtils.splitByCharacterType("ab   de fg") = ["ab", "   ", "de", " ", "fg"]
     * StringUtils.splitByCharacterType("ab:cd:ef")   = ["ab", ":", "cd", ":", "ef"]
     * StringUtils.splitByCharacterType("number5")    = ["number", "5"]
     * StringUtils.splitByCharacterType("fooBar")     = ["foo", "B", "ar"]
     * StringUtils.splitByCharacterType("foo200Bar")  = ["foo", "200", "B", "ar"]
     * StringUtils.splitByCharacterType("ASFRules")   = ["ASFR", "ules"]
     * </pre>
     *
     * @param str the String to split, may be {@code null}
     * @return an array of parsed Strings, {@code null} if null String input
     * @since 2.4
     */
    public static String[] splitByCharacterType(String str) {
        return splitByCharacterType(str, false);
    }

    /**
     * <p/>
     * Splits a String by Character type as returned by
     * {@code java.lang.Character.getType(char)}. Groups of contiguous
     * characters of the same type are returned as complete tokens, with the
     * following exception: the character of type
     * {@code Character.UPPERCASE_LETTER}, if any, immediately preceding a token
     * of type {@code Character.LOWERCASE_LETTER} will belong to the following
     * token rather than to the preceding, if any,
     * {@code Character.UPPERCASE_LETTER} token.
     * <p/>
     * <pre>
     * StringUtils.splitByCharacterTypeCamelCase(null)         = null
     * StringUtils.splitByCharacterTypeCamelCase("")           = []
     * StringUtils.splitByCharacterTypeCamelCase("ab de fg")   = ["ab", " ", "de", " ", "fg"]
     * StringUtils.splitByCharacterTypeCamelCase("ab   de fg") = ["ab", "   ", "de", " ", "fg"]
     * StringUtils.splitByCharacterTypeCamelCase("ab:cd:ef")   = ["ab", ":", "cd", ":", "ef"]
     * StringUtils.splitByCharacterTypeCamelCase("number5")    = ["number", "5"]
     * StringUtils.splitByCharacterTypeCamelCase("fooBar")     = ["foo", "Bar"]
     * StringUtils.splitByCharacterTypeCamelCase("foo200Bar")  = ["foo", "200", "Bar"]
     * StringUtils.splitByCharacterTypeCamelCase("ASFRules")   = ["ASF", "Rules"]
     * </pre>
     *
     * @param str the String to split, may be {@code null}
     * @return an array of parsed Strings, {@code null} if null String input
     * @since 2.4
     */
    public static String[] splitByCharacterTypeCamelCase(String str) {
        return splitByCharacterType(str, true);
    }

    /**
     * <p/>
     * Splits a String by Character type as returned by
     * {@code java.lang.Character.getType(char)}. Groups of contiguous
     * characters of the same type are returned as complete tokens, with the
     * following exception: if {@code camelCase} is {@code true}, the character
     * of type {@code Character.UPPERCASE_LETTER}, if any, immediately preceding
     * a token of type {@code Character.LOWERCASE_LETTER} will belong to the
     * following token rather than to the preceding, if any,
     * {@code Character.UPPERCASE_LETTER} token.
     *
     * @param str       the String to split, may be {@code null}
     * @param camelCase whether to use so-called "camel-case" for letter types
     * @return an array of parsed Strings, {@code null} if null String input
     * @since 2.4
     */
    private static String[] splitByCharacterType(String str, boolean camelCase) {
        if (str == null) {
            return new String[0];
        }
        if (str.length() == 0) {
            return EMPTY_STRING_ARRAY;
        }
        char[] c = str.toCharArray();
        List<String> list = new ArrayList<String>();
        int tokenStart = 0;
        int currentType = Character.getType(c[tokenStart]);
        for (int pos = tokenStart + 1; pos < c.length; pos++) {
            int type = Character.getType(c[pos]);
            if (type == currentType) {
                continue;
            }
            if (camelCase && type == Character.LOWERCASE_LETTER && currentType == Character.UPPERCASE_LETTER) {
                int newTokenStart = pos - 1;
                if (newTokenStart != tokenStart) {
                    list.add(new String(c, tokenStart, newTokenStart - tokenStart));
                    tokenStart = newTokenStart;
                }
            } else {
                list.add(new String(c, tokenStart, pos - tokenStart));
                tokenStart = pos;
            }
            currentType = type;
        }
        list.add(new String(c, tokenStart, c.length - tokenStart));
        return list.toArray(new String[list.size()]);
    }

    /**
     * <p>
     * Joins the elements of the provided array into a single String containing
     * the provided list of elements.
     * </p>
     * <p/>
     * <p>
     * No separator is added to the joined String. Null objects or empty strings
     * within the array are represented by empty strings.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.join(null)            = null
     * StringUtils.join([])              = ""
     * StringUtils.join([null])          = ""
     * StringUtils.join(["a", "b", "c"]) = "abc"
     * StringUtils.join([null, "", "a"]) = "a"
     * </pre>
     *
     * @param <T>      the specific type of values to join together
     * @param elements the values to join together, may be null
     * @return the joined String, {@code null} if null array input
     * @since 3.0 Changed signature to use varargs
     */
    @SuppressWarnings("unchecked")
    public static <T> String join(T... elements) {
        return join(elements, null);
    }

    /**
     * <p>
     * Joins the elements of the provided array into a single String containing
     * the provided list of elements.
     * </p>
     * <p/>
     * <p>
     * No delimiter is added before or after the list. Null objects or empty
     * strings within the array are represented by empty strings.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.join(null, *)               = null
     * StringUtils.join([], *)                 = ""
     * StringUtils.join([null], *)             = ""
     * StringUtils.join(["a", "b", "c"], ';')  = "a;b;c"
     * StringUtils.join(["a", "b", "c"], null) = "abc"
     * StringUtils.join([null, "", "a"], ';')  = ";;a"
     * </pre>
     *
     * @param array     the array of values to join together, may be null
     * @param separator the separator character to use
     * @return the joined String, {@code null} if null array input
     * @since 2.0
     */
    public static String join(Object[] array, char separator) {
        if (array == null) {
            return null;
        }

        return join(array, separator, 0, array.length);
    }

    /**
     * <p>
     * Joins the elements of the provided array into a single String containing
     * the provided list of elements.
     * </p>
     * <p/>
     * <p>
     * No delimiter is added before or after the list. Null objects or empty
     * strings within the array are represented by empty strings.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.join(null, *)               = null
     * StringUtils.join([], *)                 = ""
     * StringUtils.join([null], *)             = ""
     * StringUtils.join(["a", "b", "c"], ';')  = "a;b;c"
     * StringUtils.join(["a", "b", "c"], null) = "abc"
     * StringUtils.join([null, "", "a"], ';')  = ";;a"
     * </pre>
     *
     * @param array      the array of values to join together, may be null
     * @param separator  the separator character to use
     * @param startIndex the first index to start joining from. It is an error to pass
     *                   in an end index past the end of the array
     * @param endIndex   the index to stop joining from (exclusive). It is an error to
     *                   pass in an end index past the end of the array
     * @return the joined String, {@code null} if null array input
     * @since 2.0
     */
    public static String join(Object[] array, char separator, int startIndex, int endIndex) {
        if (array == null) {
            return null;
        }
        int noOfItems = endIndex - startIndex;
        if (noOfItems <= 0) {
            return EMPTY;
        }

        StringBuilder buf = new StringBuilder(noOfItems * CommonPlatformConstant.LENGTH_16);

        for (int i = startIndex; i < endIndex; i++) {
            if (i > startIndex) {
                buf.append(separator);
            }
            if (array[i] != null) {
                buf.append(array[i]);
            }
        }
        return buf.toString();
    }

    /**
     * <p>
     * Joins the elements of the provided array into a single String containing
     * the provided list of elements.
     * </p>
     * <p/>
     * <p>
     * No delimiter is added before or after the list. A {@code null} separator
     * is the same as an empty String (""). Null objects or empty strings within
     * the array are represented by empty strings.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.join(null, *)                = null
     * StringUtils.join([], *)                  = ""
     * StringUtils.join([null], *)              = ""
     * StringUtils.join(["a", "b", "c"], "--")  = "a--b--c"
     * StringUtils.join(["a", "b", "c"], null)  = "abc"
     * StringUtils.join(["a", "b", "c"], "")    = "abc"
     * StringUtils.join([null, "", "a"], ',')   = ",,a"
     * </pre>
     *
     * @param array     the array of values to join together, may be null
     * @param separator the separator character to use, null treated as ""
     * @return the joined String, {@code null} if null array input
     */
    public static String join(Object[] array, String separator) {
        if (array == null) {
            return null;
        }
        return join(array, separator, 0, array.length);
    }

    /**
     * <p>
     * Joins the elements of the provided array into a single String containing
     * the provided list of elements.
     * </p>
     * <p/>
     * <p>
     * No delimiter is added before or after the list. A {@code null} separator
     * is the same as an empty String (""). Null objects or empty strings within
     * the array are represented by empty strings.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.join(null, *)                = null
     * StringUtils.join([], *)                  = ""
     * StringUtils.join([null], *)              = ""
     * StringUtils.join(["a", "b", "c"], "--")  = "a--b--c"
     * StringUtils.join(["a", "b", "c"], null)  = "abc"
     * StringUtils.join(["a", "b", "c"], "")    = "abc"
     * StringUtils.join([null, "", "a"], ',')   = ",,a"
     * </pre>
     *
     * @param array      the array of values to join together, may be null
     * @param separat    the separator character to use, null treated as ""
     * @param startIndex the first index to start joining from. It is an error to pass
     *                   in an end index past the end of the array
     * @param endIndex   the index to stop joining from (exclusive). It is an error to
     *                   pass in an end index past the end of the array
     * @return the joined String, {@code null} if null array input
     */
    public static String join(Object[] array, String separat, int startIndex, int endIndex) {
        if (array == null) {
            return null;
        }
        String separator = separat;
        if (separator == null) {
            separator = EMPTY;
        }

        // endIndex - startIndex > 0: Len = NofStrings *(len(firstString) +
        // len(separator))
        // (Assuming that all Strings are roughly equally long)
        int noOfItems = endIndex - startIndex;
        if (noOfItems <= 0) {
            return EMPTY;
        }

        StringBuilder buf = new StringBuilder(noOfItems * CommonPlatformConstant.LENGTH_16);

        for (int i = startIndex; i < endIndex; i++) {
            if (i > startIndex) {
                buf.append(separator);
            }
            if (array[i] != null) {
                buf.append(array[i]);
            }
        }
        return buf.toString();
    }

    /**
     * <p>
     * Joins the elements of the provided {@code Iterator} into a single String
     * containing the provided elements.
     * </p>
     * <p/>
     * <p>
     * No delimiter is added before or after the list. Null objects or empty
     * strings within the iteration are represented by empty strings.
     * </p>
     * <p/>
     * <p>
     * See the examples here: {@link #join(Object[], char)}.
     * </p>
     *
     * @param iterator  the {@code Iterator} of values to join together, may be null
     * @param separator the separator character to use
     * @return the joined String, {@code null} if null iterator input
     * @since 2.0
     */
    public static String join(Iterator<?> iterator, char separator) {

        // handle null, zero and one elements before building a buffer
        if (iterator == null) {
            return null;
        }
        if (!iterator.hasNext()) {
            return EMPTY;
        }
        Object first = iterator.next();
        if (!iterator.hasNext()) {
            return first == null ? "" : first.toString();
        }

        // two or more elements
        StringBuilder buf = new StringBuilder(CommonPlatformConstant.LENGTH_256);
        // probably too small
        if (first != null) {
            buf.append(first);
        }

        while (iterator.hasNext()) {
            buf.append(separator);
            Object obj = iterator.next();
            if (obj != null) {
                buf.append(obj);
            }
        }

        return buf.toString();
    }

    /**
     * <p>
     * Joins the elements of the provided {@code Iterator} into a single String
     * containing the provided elements.
     * </p>
     * <p/>
     * <p>
     * No delimiter is added before or after the list. A {@code null} separator
     * is the same as an empty String ("").
     * </p>
     * <p/>
     * <p>
     * See the examples here: {@link #join(Object[], String)}.
     * </p>
     *
     * @param iterator  the {@code Iterator} of values to join together, may be null
     * @param separator the separator character to use, null treated as ""
     * @return the joined String, {@code null} if null iterator input
     */
    public static String join(Iterator<?> iterator, String separator) {

        // handle null, zero and one elements before building a buffer
        if (iterator == null) {
            return null;
        }
        if (!iterator.hasNext()) {
            return EMPTY;
        }
        Object first = iterator.next();
        if (!iterator.hasNext()) {
            return first == null ? "" : first.toString();
        }

        // two or more elements
        StringBuilder buf = new StringBuilder(CommonPlatformConstant.LENGTH_256);
        // probably too small
        if (first != null) {
            buf.append(first);
        }

        while (iterator.hasNext()) {
            if (separator != null) {
                buf.append(separator);
            }
            Object obj = iterator.next();
            if (obj != null) {
                buf.append(obj);
            }
        }
        return buf.toString();
    }

    /**
     * <p>
     * Joins the elements of the provided {@code Iterable} into a single String
     * containing the provided elements.
     * </p>
     * <p/>
     * <p>
     * No delimiter is added before or after the list. Null objects or empty
     * strings within the iteration are represented by empty strings.
     * </p>
     * <p/>
     * <p>
     * See the examples here: {@link #join(Object[], char)}.
     * </p>
     *
     * @param iterable  the {@code Iterable} providing the values to join together,
     *                  may be null
     * @param separator the separator character to use
     * @return the joined String, {@code null} if null iterator input
     * @since 2.3
     */
    public static String join(Iterable<?> iterable, char separator) {
        if (iterable == null) {
            return null;
        }
        return join(iterable.iterator(), separator);
    }

    /**
     * <p>
     * Joins the elements of the provided {@code Iterable} into a single String
     * containing the provided elements.
     * </p>
     * <p/>
     * <p>
     * No delimiter is added before or after the list. A {@code null} separator
     * is the same as an empty String ("").
     * </p>
     * <p/>
     * <p>
     * See the examples here: {@link #join(Object[], String)}.
     * </p>
     *
     * @param iterable  the {@code Iterable} providing the values to join together,
     *                  may be null
     * @param separator the separator character to use, null treated as ""
     * @return the joined String, {@code null} if null iterator input
     * @since 2.3
     */
    public static String join(Iterable<?> iterable, String separator) {
        if (iterable == null) {
            return null;
        }
        return join(iterable.iterator(), separator);
    }

    /**
     * <p>
     * Deletes all whitespaces from a String as defined by
     * {@link Character#isWhitespace(char)}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.deleteWhitespace(null)         = null
     * StringUtils.deleteWhitespace("")           = ""
     * StringUtils.deleteWhitespace("abc")        = "abc"
     * StringUtils.deleteWhitespace("   ab  c  ") = "abc"
     * </pre>
     *
     * @param str the String to delete whitespace from, may be null
     * @return the String without whitespaces, {@code null} if null String input
     */
    public static String deleteWhitespace(String str) {
        if (isEmpty(str)) {
            return str;
        }
        int sz = str.length();
        char[] chs = new char[sz];
        int count = 0;
        for (int i = 0; i < sz; i++) {
            if (!Character.isWhitespace(str.charAt(i))) {
                chs[count++] = str.charAt(i);
            }
        }
        if (count == sz) {
            return str;
        }
        return new String(chs, 0, count);
    }

    /**
     * <p>
     * Removes a substring only if it is at the beginning of a source string,
     * otherwise returns the source string.
     * </p>
     * <p/>
     * <p>
     * A {@code null} source string will return {@code null}. An empty ("")
     * source string will return the empty string. A {@code null} search string
     * will return the source string.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.removeStart(null, *)      = null
     * StringUtils.removeStart("", *)        = ""
     * StringUtils.removeStart(*, null)      = *
     * StringUtils.removeStart("www.domain.com", "www.")   = "domain.com"
     * StringUtils.removeStart("domain.com", "www.")       = "domain.com"
     * StringUtils.removeStart("www.domain.com", "domain") = "www.domain.com"
     * StringUtils.removeStart("abc", "")    = "abc"
     * </pre>
     *
     * @param str    the source String to search, may be null
     * @param remove the String to search for and remove, may be null
     * @return the substring with the string removed if found, {@code null} if
     * null String input
     * @since 2.1
     */
    public static String removeStart(String str, String remove) {
        if (isEmpty(str) || isEmpty(remove)) {
            return str;
        }
        if (str.startsWith(remove)) {
            return str.substring(remove.length());
        }
        return str;
    }

    /**
     * <p>
     * Case insensitive removal of a substring if it is at the beginning of a
     * source string, otherwise returns the source string.
     * </p>
     * <p/>
     * <p>
     * A {@code null} source string will return {@code null}. An empty ("")
     * source string will return the empty string. A {@code null} search string
     * will return the source string.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.removeStartIgnoreCase(null, *)      = null
     * StringUtils.removeStartIgnoreCase("", *)        = ""
     * StringUtils.removeStartIgnoreCase(*, null)      = *
     * StringUtils.removeStartIgnoreCase("www.domain.com", "www.")   = "domain.com"
     * StringUtils.removeStartIgnoreCase("www.domain.com", "WWW.")   = "domain.com"
     * StringUtils.removeStartIgnoreCase("domain.com", "www.")       = "domain.com"
     * StringUtils.removeStartIgnoreCase("www.domain.com", "domain") = "www.domain.com"
     * StringUtils.removeStartIgnoreCase("abc", "")    = "abc"
     * </pre>
     *
     * @param str    the source String to search, may be null
     * @param remove the String to search for (case insensitive) and remove, may be
     *               null
     * @return the substring with the string removed if found, {@code null} if
     * null String input
     * @since 2.4
     */
    public static String removeStartIgnoreCase(String str, String remove) {
        if (isEmpty(str) || isEmpty(remove)) {
            return str;
        }
        if (startsWithIgnoreCase(str, remove)) {
            return str.substring(remove.length());
        }
        return str;
    }

    /**
     * <p>
     * Removes a substring only if it is at the end of a source string,
     * otherwise returns the source string.
     * </p>
     * <p/>
     * <p>
     * A {@code null} source string will return {@code null}. An empty ("")
     * source string will return the empty string. A {@code null} search string
     * will return the source string.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.removeEnd(null, *)      = null
     * StringUtils.removeEnd("", *)        = ""
     * StringUtils.removeEnd(*, null)      = *
     * StringUtils.removeEnd("www.domain.com", ".com.")  = "www.domain.com"
     * StringUtils.removeEnd("www.domain.com", ".com")   = "www.domain"
     * StringUtils.removeEnd("www.domain.com", "domain") = "www.domain.com"
     * StringUtils.removeEnd("abc", "")    = "abc"
     * </pre>
     *
     * @param str    the source String to search, may be null
     * @param remove the String to search for and remove, may be null
     * @return the substring with the string removed if found, {@code null} if
     * null String input
     * @since 2.1
     */
    public static String removeEnd(String str, String remove) {
        if (isEmpty(str) || isEmpty(remove)) {
            return str;
        }
        if (str.endsWith(remove)) {
            return str.substring(0, str.length() - remove.length());
        }
        return str;
    }

    /**
     * <p>
     * Case insensitive removal of a substring if it is at the end of a source
     * string, otherwise returns the source string.
     * </p>
     * <p/>
     * <p>
     * A {@code null} source string will return {@code null}. An empty ("")
     * source string will return the empty string. A {@code null} search string
     * will return the source string.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.removeEndIgnoreCase(null, *)      = null
     * StringUtils.removeEndIgnoreCase("", *)        = ""
     * StringUtils.removeEndIgnoreCase(*, null)      = *
     * StringUtils.removeEndIgnoreCase("www.domain.com", ".com.")  = "www.domain.com"
     * StringUtils.removeEndIgnoreCase("www.domain.com", ".com")   = "www.domain"
     * StringUtils.removeEndIgnoreCase("www.domain.com", "domain") = "www.domain.com"
     * StringUtils.removeEndIgnoreCase("abc", "")    = "abc"
     * StringUtils.removeEndIgnoreCase("www.domain.com", ".COM") = "www.domain")
     * StringUtils.removeEndIgnoreCase("www.domain.COM", ".com") = "www.domain")
     * </pre>
     *
     * @param str    the source String to search, may be null
     * @param remove the String to search for (case insensitive) and remove, may be
     *               null
     * @return the substring with the string removed if found, {@code null} if
     * null String input
     * @since 2.4
     */
    public static String removeEndIgnoreCase(String str, String remove) {
        if (isEmpty(str) || isEmpty(remove)) {
            return str;
        }
        if (endsWithIgnoreCase(str, remove)) {
            return str.substring(0, str.length() - remove.length());
        }
        return str;
    }

    /**
     * <p>
     * Removes all occurrences of a substring from within the source string.
     * </p>
     * <p/>
     * <p>
     * A {@code null} source string will return {@code null}. An empty ("")
     * source string will return the empty string. A {@code null} remove string
     * will return the source string. An empty ("") remove string will return
     * the source string.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.remove(null, *)        = null
     * StringUtils.remove("", *)          = ""
     * StringUtils.remove(*, null)        = *
     * StringUtils.remove(*, "")          = *
     * StringUtils.remove("queued", "ue") = "qd"
     * StringUtils.remove("queued", "zz") = "queued"
     * </pre>
     *
     * @param str    the source String to search, may be null
     * @param remove the String to search for and remove, may be null
     * @return the substring with the string removed if found, {@code null} if
     * null String input
     * @since 2.1
     */
    public static String remove(String str, String remove) {
        if (isEmpty(str) || isEmpty(remove)) {
            return str;
        }
        return replace(str, remove, EMPTY, -1);
    }

    /**
     * <p>
     * Removes all occurrences of a character from within the source string.
     * </p>
     * <p/>
     * <p>
     * A {@code null} source string will return {@code null}. An empty ("")
     * source string will return the empty string.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.remove(null, *)       = null
     * StringUtils.remove("", *)         = ""
     * StringUtils.remove("queued", 'u') = "qeed"
     * StringUtils.remove("queued", 'z') = "queued"
     * </pre>
     *
     * @param str    the source String to search, may be null
     * @param remove the char to search for and remove, may be null
     * @return the substring with the char removed if found, {@code null} if
     * null String input
     * @since 2.1
     */
    public static String remove(String str, char remove) {
        if (isEmpty(str) || str.indexOf(remove) == INDEX_NOT_FOUND) {
            return str;
        }
        char[] chars = str.toCharArray();
        int pos = 0;
        for (int i = 0; i < chars.length; i++) {
            if (chars[i] != remove) {
                chars[pos++] = chars[i];
            }
        }
        return new String(chars, 0, pos);
    }

    /**
     * <p>
     * Replaces a String with another String inside a larger String, once.
     * </p>
     * <p/>
     * <p>
     * A {@code null} reference passed to this method is a no-op.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.replaceOnce(null, *, *)        = null
     * StringUtils.replaceOnce("", *, *)          = ""
     * StringUtils.replaceOnce("any", null, *)    = "any"
     * StringUtils.replaceOnce("any", *, null)    = "any"
     * StringUtils.replaceOnce("any", "", *)      = "any"
     * StringUtils.replaceOnce("aba", "a", null)  = "aba"
     * StringUtils.replaceOnce("aba", "a", "")    = "ba"
     * StringUtils.replaceOnce("aba", "a", "z")   = "zba"
     * </pre>
     *
     * @param text         text to search and replace in, may be null
     * @param searchString the String to search for, may be null
     * @param replacement  the String to replace with, may be null
     * @return the text with any replacements processed, {@code null} if null
     * String input
     * @see #replace(String text, String searchString, String replacement, int
     * max)
     */
    public static String replaceOnce(String text, String searchString, String replacement) {
        return replace(text, searchString, replacement, 1);
    }

    /**
     * <p>
     * Replaces all occurrences of a String within another String.
     * </p>
     * <p/>
     * <p>
     * A {@code null} reference passed to this method is a no-op.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.replace(null, *, *)        = null
     * StringUtils.replace("", *, *)          = ""
     * StringUtils.replace("any", null, *)    = "any"
     * StringUtils.replace("any", *, null)    = "any"
     * StringUtils.replace("any", "", *)      = "any"
     * StringUtils.replace("aba", "a", null)  = "aba"
     * StringUtils.replace("aba", "a", "")    = "b"
     * StringUtils.replace("aba", "a", "z")   = "zbz"
     * </pre>
     *
     * @param text         text to search and replace in, may be null
     * @param searchString the String to search for, may be null
     * @param replacement  the String to replace it with, may be null
     * @return the text with any replacements processed, {@code null} if null
     * String input
     * @see #replace(String text, String searchString, String replacement, int
     * max)
     */
    public static String replace(String text, String searchString, String replacement) {
        return replace(text, searchString, replacement, -1);
    }

    /**
     * <p>
     * Replaces a String with another String inside a larger String, for the
     * first {@code max} values of the search String.
     * </p>
     * <p/>
     * <p>
     * A {@code null} reference passed to this method is a no-op.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.replace(null, *, *, *)         = null
     * StringUtils.replace("", *, *, *)           = ""
     * StringUtils.replace("any", null, *, *)     = "any"
     * StringUtils.replace("any", *, null, *)     = "any"
     * StringUtils.replace("any", "", *, *)       = "any"
     * StringUtils.replace("any", *, *, 0)        = "any"
     * StringUtils.replace("abaa", "a", null, -1) = "abaa"
     * StringUtils.replace("abaa", "a", "", -1)   = "b"
     * StringUtils.replace("abaa", "a", "z", 0)   = "abaa"
     * StringUtils.replace("abaa", "a", "z", 1)   = "zbaa"
     * StringUtils.replace("abaa", "a", "z", 2)   = "zbza"
     * StringUtils.replace("abaa", "a", "z", -1)  = "zbzz"
     * </pre>
     *
     * @param text         text to search and replace in, may be null
     * @param searchString the String to search for, may be null
     * @param replacement  the String to replace it with, may be null
     * @param maximum      maximum number of values to replace, or {@code -1} if no
     *                     maximum
     * @return the text with any replacements processed, {@code null} if null
     * String input
     */
    public static String replace(String text, String searchString, String replacement, int maximum) {
        int max = maximum;
        if (isEmpty(text) || isEmpty(searchString) || replacement == null || max == 0) {
            return text;
        }
        int start = 0;
        int end = text.indexOf(searchString, start);
        if (end == INDEX_NOT_FOUND) {
            return text;
        }
        int replLength = searchString.length();
        int increase = replacement.length() - replLength;
        increase = increase < 0 ? 0 : increase;
        increase *= max < 0 ? CommonPlatformConstant.LENGTH_16
                : max > CommonPlatformConstant.LENGTH_64 ? CommonPlatformConstant.LENGTH_64 : max;
        StringBuilder buf = new StringBuilder(text.length() + increase);
        while (end != INDEX_NOT_FOUND) {
            buf.append(text.substring(start, end)).append(replacement);
            start = end + replLength;
            if (--max == 0) {
                break;
            }
            end = text.indexOf(searchString, start);
        }
        buf.append(text.substring(start));
        return buf.toString();
    }

    /**
     * <p>
     * Replaces all occurrences of Strings within another String.
     * </p>
     * <p/>
     * <p>
     * A {@code null} reference passed to this method is a no-op, or if any
     * "search string" or "string to replace" is null, that replace will be
     * ignored. This will not repeat. For repeating replaces, call the
     * overloaded method.
     * </p>
     * <p/>
     * <pre>
     *  StringUtils.replaceEach(null, *, *)        = null
     *  StringUtils.replaceEach("", *, *)          = ""
     *  StringUtils.replaceEach("aba", null, null) = "aba"
     *  StringUtils.replaceEach("aba", new String[0], null) = "aba"
     *  StringUtils.replaceEach("aba", null, new String[0]) = "aba"
     *  StringUtils.replaceEach("aba", new String[]{"a"}, null)  = "aba"
     *  StringUtils.replaceEach("aba", new String[]{"a"}, new String[]{""})  = "b"
     *  StringUtils.replaceEach("aba", new String[]{null}, new String[]{"a"})  = "aba"
     *  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"w", "t"})  = "wcte"
     *  (example of how it does not repeat)
     *  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "t"})  = "dcte"
     * </pre>
     *
     * @param text            text to search and replace in, no-op if null
     * @param searchList      the Strings to search for, no-op if null
     * @param replacementList the Strings to replace them with, no-op if null
     * @return the text with any replacements processed, {@code null} if null
     * String input
     * @throws IllegalArgumentException if the lengths of the arrays are not the same (null is ok,
     *                                  and/or size 0)
     * @since 2.4
     */
    public static String replaceEach(String text, String[] searchList, String[] replacementList) {
        return replaceEach(text, searchList, replacementList, false, 0);
    }

    /**
     * <p>
     * Replaces all occurrences of Strings within another String.
     * </p>
     * <p/>
     * <p>
     * A {@code null} reference passed to this method is a no-op, or if any
     * "search string" or "string to replace" is null, that replace will be
     * ignored.
     * </p>
     * <p/>
     * <pre>
     *  StringUtils.replaceEach(null, *, *, *) = null
     *  StringUtils.replaceEach("", *, *, *) = ""
     *  StringUtils.replaceEach("aba", null, null, *) = "aba"
     *  StringUtils.replaceEach("aba", new String[0], null, *) = "aba"
     *  StringUtils.replaceEach("aba", null, new String[0], *) = "aba"
     *  StringUtils.replaceEach("aba", new String[]{"a"}, null, *) = "aba"
     *  StringUtils.replaceEach("aba", new String[]{"a"}, new String[]{""}, *) = "b"
     *  StringUtils.replaceEach("aba", new String[]{null}, new String[]{"a"}, *) = "aba"
     *  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"w", "t"}, *) = "wcte"
     *  (example of how it repeats)
     *  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "t"}, false) = "dcte"
     *  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "t"}, true) = "tcte"
     *  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "ab"}, true) = IllegalStateException
     *  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "ab"}, false) = "dcabe"
     * </pre>
     *
     * @param text            text to search and replace in, no-op if null
     * @param searchList      the Strings to search for, no-op if null
     * @param replacementList the Strings to replace them with, no-op if null
     * @return the text with any replacements processed, {@code null} if null
     * String input
     * @throws IllegalStateException    if the search is repeating and there is an endless loop due
     *                                  to outputs of one being inputs to another
     * @throws IllegalArgumentException if the lengths of the arrays are not the same (null is ok,
     *                                  and/or size 0)
     * @since 2.4
     */
    public static String replaceEachRepeatedly(String text, String[] searchList, String[] replacementList) {
        // timeToLive should be 0 if not used or nothing to replace, else it's
        // the length of the replace array
        int timeToLive = searchList == null ? 0 : searchList.length;
        return replaceEach(text, searchList, replacementList, true, timeToLive);
    }

    /**
     * <p>
     * Replaces all occurrences of Strings within another String.
     * </p>
     * <p/>
     * <p>
     * A {@code null} reference passed to this method is a no-op, or if any
     * "search string" or "string to replace" is null, that replace will be
     * ignored.
     * </p>
     * <p/>
     * <pre>
     *  StringUtils.replaceEach(null, *, *, *) = null
     *  StringUtils.replaceEach("", *, *, *) = ""
     *  StringUtils.replaceEach("aba", null, null, *) = "aba"
     *  StringUtils.replaceEach("aba", new String[0], null, *) = "aba"
     *  StringUtils.replaceEach("aba", null, new String[0], *) = "aba"
     *  StringUtils.replaceEach("aba", new String[]{"a"}, null, *) = "aba"
     *  StringUtils.replaceEach("aba", new String[]{"a"}, new String[]{""}, *) = "b"
     *  StringUtils.replaceEach("aba", new String[]{null}, new String[]{"a"}, *) = "aba"
     *  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"w", "t"}, *) = "wcte"
     *  (example of how it repeats)
     *  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "t"}, false) = "dcte"
     *  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "t"}, true) = "tcte"
     *  StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "ab"}, *) = IllegalStateException
     * </pre>
     *
     * @param text            text to search and replace in, no-op if null
     * @param searchList      the Strings to search for, no-op if null
     * @param replacementList the Strings to replace them with, no-op if null
     * @param repeat          if true, then replace repeatedly until there are no more
     *                        possible replacements or timeToLive < 0
     * @param timeToLive      if less than 0 then there is a circular reference and endless
     *                        loop
     * @return the text with any replacements processed, {@code null} if null
     * String input
     * @throws IllegalStateException    if the search is repeating and there is an endless loop due
     *                                  to outputs of one being inputs to another
     * @throws IllegalArgumentException if the lengths of the arrays are not the same (null is ok,
     *                                  and/or size 0)
     * @since 2.4
     */
    private static String replaceEach(String text, String[] searchList, String[] replacementList, boolean repeat,
            int timeToLive) {

        // mchyzer Performance note: This creates very few new objects (one
        // major goal)
        // let me know if there are performance requests, we can create a
        // harness to measure

        if (text == null || text.length() == 0 || searchList == null || searchList.length == 0
                || replacementList == null || replacementList.length == 0) {
            return text;
        }

        // if recursing, this shouldn't be less than 0
        if (timeToLive < 0) {
            throw new IllegalStateException("Aborting to protect against StackOverflowError - "
                    + "output of one loop is the input of another");
        }

        int searchLength = searchList.length;
        int replacementLength = replacementList.length;

        // make sure lengths are ok, these need to be equal
        if (searchLength != replacementLength) {
            throw new IllegalArgumentException(
                    "Search and Replace array lengths don't match: " + searchLength + " vs " + replacementLength);
        }

        // keep track of which still have matches
        boolean[] noMoreMatchesForReplIndex = new boolean[searchLength];

        // index on index that the match was found
        int textIndex = -1;
        int replaceIndex = -1;
        int tempIndex = -1;

        // index of replace array that will replace the search string found
        // NOTE: logic duplicated below START
        for (int i = 0; i < searchLength; i++) {
            if (noMoreMatchesForReplIndex[i] || searchList[i] == null || searchList[i].length() == 0
                    || replacementList[i] == null) {
                continue;
            }
            tempIndex = text.indexOf(searchList[i]);

            // see if we need to keep searching for this
            if (tempIndex == -1) {
                noMoreMatchesForReplIndex[i] = true;
            } else {
                if (textIndex == -1 || tempIndex < textIndex) {
                    textIndex = tempIndex;
                    replaceIndex = i;
                }
            }
        }
        // NOTE: logic mostly below END

        // no search strings found, we are done
        if (textIndex == -1) {
            return text;
        }

        int start = 0;

        // get a good guess on the size of the result buffer so it doesn't have
        // to double if it goes over a bit
        int increase = 0;

        // count the replacement text elements that are larger than their
        // corresponding text being replaced
        for (int i = 0; i < searchList.length; i++) {
            if (searchList[i] == null || replacementList[i] == null) {
                continue;
            }
            int greater = replacementList[i].length() - searchList[i].length();
            if (greater > 0) {
                increase += CommonPlatformConstant.LENGTH_3 * greater;
            }
        }
        // have upper-bound at 20% increase, then let Java take over
        increase = Math.min(increase, text.length() / CommonPlatformConstant.LENGTH_5);

        StringBuilder buf = new StringBuilder(text.length() + increase);

        while (textIndex != -1) {

            for (int i = start; i < textIndex; i++) {
                buf.append(text.charAt(i));
            }
            buf.append(replacementList[replaceIndex]);

            start = textIndex + searchList[replaceIndex].length();

            textIndex = -1;
            replaceIndex = -1;
            tempIndex = -1;
            // find the next earliest match
            // NOTE: logic mostly duplicated above START
            for (int i = 0; i < searchLength; i++) {
                if (noMoreMatchesForReplIndex[i] || searchList[i] == null || searchList[i].length() == 0
                        || replacementList[i] == null) {
                    continue;
                }
                tempIndex = text.indexOf(searchList[i], start);

                // see if we need to keep searching for this
                if (tempIndex == -1) {
                    noMoreMatchesForReplIndex[i] = true;
                } else {
                    if (textIndex == -1 || tempIndex < textIndex) {
                        textIndex = tempIndex;
                        replaceIndex = i;
                    }
                }
            }
            // NOTE: logic duplicated above END

        }
        int textLength = text.length();
        for (int i = start; i < textLength; i++) {
            buf.append(text.charAt(i));
        }
        String result = buf.toString();
        if (!repeat) {
            return result;
        }

        return replaceEach(result, searchList, replacementList, repeat, timeToLive - 1);
    }

    /**
     * <p>
     * Replaces all occurrences of a character in a String with another. This is
     * a null-safe version of {@link String#replace(char, char)}.
     * </p>
     * <p/>
     * <p>
     * A {@code null} string input returns {@code null}. An empty ("") string
     * input returns an empty string.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.replaceChars(null, *, *)        = null
     * StringUtils.replaceChars("", *, *)          = ""
     * StringUtils.replaceChars("abcba", 'b', 'y') = "aycya"
     * StringUtils.replaceChars("abcba", 'z', 'y') = "abcba"
     * </pre>
     *
     * @param str         String to replace characters in, may be null
     * @param searchChar  the character to search for, may be null
     * @param replaceChar the character to replace, may be null
     * @return modified String, {@code null} if null string input
     * @since 2.0
     */
    public static String replaceChars(String str, char searchChar, char replaceChar) {
        if (str == null) {
            return null;
        }
        return str.replace(searchChar, replaceChar);
    }

    /**
     * <p>
     * Replaces multiple characters in a String in one go. This method can also
     * be used to delete characters.
     * </p>
     * <p/>
     * <p>
     * For example:<br />
     * <code>replaceChars(&quot;hello&quot;, &quot;ho&quot;, &quot;jy&quot;) = jelly</code>
     * .
     * </p>
     * <p/>
     * <p>
     * A {@code null} string input returns {@code null}. An empty ("") string
     * input returns an empty string. A null or empty set of search characters
     * returns the input string.
     * </p>
     * <p/>
     * <p>
     * The length of the search characters should normally equal the length of
     * the replace characters. If the search characters is longer, then the
     * extra search characters are deleted. If the search characters is shorter,
     * then the extra replace characters are ignored.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.replaceChars(null, *, *)           = null
     * StringUtils.replaceChars("", *, *)             = ""
     * StringUtils.replaceChars("abc", null, *)       = "abc"
     * StringUtils.replaceChars("abc", "", *)         = "abc"
     * StringUtils.replaceChars("abc", "b", null)     = "ac"
     * StringUtils.replaceChars("abc", "b", "")       = "ac"
     * StringUtils.replaceChars("abcba", "bc", "yz")  = "ayzya"
     * StringUtils.replaceChars("abcba", "bc", "y")   = "ayya"
     * StringUtils.replaceChars("abcba", "bc", "yzx") = "ayzya"
     * </pre>
     *
     * @param str         String to replace characters in, may be null
     * @param searchChars a set of characters to search for, may be null
     * @param replace     a set of characters to replace, may be null
     * @return modified String, {@code null} if null string input
     * @since 2.0
     */
    public static String replaceChars(String str, String searchChars, String replace) {
        if (isEmpty(str) || isEmpty(searchChars)) {
            return str;
        }
        String replaceChars = replace;
        if (replaceChars == null) {
            replaceChars = EMPTY;
        }
        boolean modified = false;
        int replaceCharsLength = replaceChars.length();
        int strLength = str.length();
        StringBuilder buf = new StringBuilder(strLength);
        for (int i = 0; i < strLength; i++) {
            char ch = str.charAt(i);
            int index = searchChars.indexOf(ch);
            if (index >= 0) {
                modified = true;
                if (index < replaceCharsLength) {
                    buf.append(replaceChars.charAt(index));
                }
            } else {
                buf.append(ch);
            }
        }
        if (modified) {
            return buf.toString();
        }
        return str;
    }

    // Overlay
    // -----------------------------------------------------------------------

    /**
     * <p>
     * Overlays part of a String with another String.
     * </p>
     * <p/>
     * <p>
     * A {@code null} string input returns {@code null}. A negative index is
     * treated as zero. An index greater than the string length is treated as
     * the string length. The start index is always the smaller of the two
     * indices.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.overlay(null, *, *, *)            = null
     * StringUtils.overlay("", "abc", 0, 0)          = "abc"
     * StringUtils.overlay("abcdef", null, 2, 4)     = "abef"
     * StringUtils.overlay("abcdef", "", 2, 4)       = "abef"
     * StringUtils.overlay("abcdef", "", 4, 2)       = "abef"
     * StringUtils.overlay("abcdef", "zzzz", 2, 4)   = "abzzzzef"
     * StringUtils.overlay("abcdef", "zzzz", 4, 2)   = "abzzzzef"
     * StringUtils.overlay("abcdef", "zzzz", -1, 4)  = "zzzzef"
     * StringUtils.overlay("abcdef", "zzzz", 2, 8)   = "abzzzz"
     * StringUtils.overlay("abcdef", "zzzz", -2, -3) = "zzzzabcdef"
     * StringUtils.overlay("abcdef", "zzzz", 8, 10)  = "abcdefzzzz"
     * </pre>
     *
     * @param str      the String to do overlaying in, may be null
     * @param over     the String to overlay, may be null
     * @param startPos the position to start overlaying at
     * @param endPos   the position to stop overlaying before
     * @return overlayed String, {@code null} if null String input
     * @since 2.0
     */
    public static String overlay(String str, String over, int startPos, int endPos) {
        if (str == null) {
            return null;
        }
        String overlay = over;
        int start = startPos, end = endPos;
        if (overlay == null) {
            overlay = EMPTY;
        }
        int len = str.length();
        if (start < 0) {
            start = 0;
        }
        if (start > len) {
            start = len;
        }
        if (end < 0) {
            end = 0;
        }
        if (end > len) {
            end = len;
        }
        if (start > end) {
            int temp = start;
            start = end;
            end = temp;
        }
        return new StringBuilder(len + start - end + overlay.length() + 1).append(str.substring(0, start))
                .append(overlay).append(str.substring(end)).toString();
    }

    /**
     * <p>
     * Removes one newline from end of a String if it's there, otherwise leave
     * it alone. A newline is &quot;{@code \n}&quot;, &quot;{@code \r}&quot;, or
     * &quot;{@code \r\n}&quot;.
     * </p>
     * <p/>
     * <p>
     * NOTE: This method changed in 2.0. It now more closely matches Perl chomp.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.chomp(null)          = null
     * StringUtils.chomp("")            = ""
     * StringUtils.chomp("abc \r")      = "abc "
     * StringUtils.chomp("abc\n")       = "abc"
     * StringUtils.chomp("abc\r\n")     = "abc"
     * StringUtils.chomp("abc\r\n\r\n") = "abc\r\n"
     * StringUtils.chomp("abc\n\r")     = "abc\n"
     * StringUtils.chomp("abc\n\rabc")  = "abc\n\rabc"
     * StringUtils.chomp("\r")          = ""
     * StringUtils.chomp("\n")          = ""
     * StringUtils.chomp("\r\n")        = ""
     * </pre>
     *
     * @param str the String to chomp a newline from, may be null
     * @return String without newline, {@code null} if null String input
     */
    public static String chomp(String str) {
        if (isEmpty(str)) {
            return str;
        }

        if (str.length() == 1) {
            char ch = str.charAt(0);
            if (ch == CharUtils.CR || ch == CharUtils.LF) {
                return EMPTY;
            }
            return str;
        }

        int lastIdx = str.length() - 1;
        char last = str.charAt(lastIdx);

        if (last == CharUtils.LF) {
            if (str.charAt(lastIdx - 1) == CharUtils.CR) {
                lastIdx--;
            }
        } else if (last != CharUtils.CR) {
            lastIdx++;
        }
        return str.substring(0, lastIdx);
    }

    /**
     * <p>
     * Removes {@code separator} from the end of {@code str} if it's there,
     * otherwise leave it alone.
     * </p>
     * <p/>
     * <p>
     * NOTE: This method changed in version 2.0. It now more closely matches
     * Perl chomp. For the previous behavior, use
     * {@link #substringBeforeLast(String, String)}. This method uses
     * {@link String#endsWith(String)}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.chomp(null, *)         = null
     * StringUtils.chomp("", *)           = ""
     * StringUtils.chomp("foobar", "bar") = "foo"
     * StringUtils.chomp("foobar", "baz") = "foobar"
     * StringUtils.chomp("foo", "foo")    = ""
     * StringUtils.chomp("foo ", "foo")   = "foo "
     * StringUtils.chomp(" foo", "foo")   = " "
     * StringUtils.chomp("foo", "foooo")  = "foo"
     * StringUtils.chomp("foo", "")       = "foo"
     * StringUtils.chomp("foo", null)     = "foo"
     * </pre>
     *
     * @param str       the String to chomp from, may be null
     * @param separator separator String, may be null
     * @return String without trailing separator, {@code null} if null String
     * input
     * {@link StringUtils#removeEnd(String, String)} instead
     */
    public static String chomp(String str, String separator) {
        return removeEnd(str, separator);
    }

    /**
     * <p>
     * Remove the last character from a String.
     * </p>
     * <p/>
     * <p>
     * If the String ends in {@code \r\n}, then remove both of them.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.chop(null)          = null
     * StringUtils.chop("")            = ""
     * StringUtils.chop("abc \r")      = "abc "
     * StringUtils.chop("abc\n")       = "abc"
     * StringUtils.chop("abc\r\n")     = "abc"
     * StringUtils.chop("abc")         = "ab"
     * StringUtils.chop("abc\nabc")    = "abc\nab"
     * StringUtils.chop("a")           = ""
     * StringUtils.chop("\r")          = ""
     * StringUtils.chop("\n")          = ""
     * StringUtils.chop("\r\n")        = ""
     * </pre>
     *
     * @param str the String to chop last character from, may be null
     * @return String without last character, {@code null} if null String input
     */
    public static String chop(String str) {
        if (str == null) {
            return null;
        }
        int strLen = str.length();
        if (strLen < CommonPlatformConstant.LENGTH_2) {
            return EMPTY;
        }
        int lastIdx = strLen - 1;
        String ret = str.substring(0, lastIdx);
        char last = str.charAt(lastIdx);
        if (last == CharUtils.LF && ret.charAt(lastIdx - 1) == CharUtils.CR) {
            return ret.substring(0, lastIdx - 1);
        }
        return ret;
    }

    /**
     * <p>
     * Repeat a String {@code repeat} times to form a new String.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.repeat(null, 2) = null
     * StringUtils.repeat("", 0)   = ""
     * StringUtils.repeat("", 2)   = ""
     * StringUtils.repeat("a", 3)  = "aaa"
     * StringUtils.repeat("ab", 2) = "abab"
     * StringUtils.repeat("a", -2) = ""
     * </pre>
     *
     * @param str    the String to repeat, may be null
     * @param repeat number of times to repeat str, negative treated as zero
     * @return a new String consisting of the original String repeated,
     * {@code null} if null String input
     */
    public static String repeat(String str, int repeat) {
        // Performance tuned for 2.0 (JDK1.4)

        if (str == null) {
            return null;
        }
        if (repeat <= 0) {
            return EMPTY;
        }
        int inputLength = str.length();
        if (repeat == 1 || inputLength == 0) {
            return str;
        }
        if (inputLength == 1 && repeat <= PAD_LIMIT) {
            return repeat(str.charAt(0), repeat);
        }

        int outputLength = inputLength * repeat;
        switch (inputLength) {
        case 1:
            return repeat(str.charAt(0), repeat);
        case CommonPlatformConstant.LENGTH_2:
            char ch0 = str.charAt(0);
            char ch1 = str.charAt(1);
            char[] output2 = new char[outputLength];
            for (int i = repeat * CommonPlatformConstant.LENGTH_2
                    - CommonPlatformConstant.LENGTH_2; i >= 0; i--, i--) {
                output2[i] = ch0;
                output2[i + 1] = ch1;
            }
            return new String(output2);
        default:
            StringBuilder buf = new StringBuilder(outputLength);
            for (int i = 0; i < repeat; i++) {
                buf.append(str);
            }
            return buf.toString();
        }
    }

    /**
     * <p>
     * Repeat a String {@code repeat} times to form a new String, with a String
     * separator injected each time.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.repeat(null, null, 2) = null
     * StringUtils.repeat(null, "x", 2)  = null
     * StringUtils.repeat("", null, 0)   = ""
     * StringUtils.repeat("", "", 2)     = ""
     * StringUtils.repeat("", "x", 3)    = "xxx"
     * StringUtils.repeat("?", ", ", 3)  = "?, ?, ?"
     * </pre>
     *
     * @param str       the String to repeat, may be null
     * @param separator the String to inject, may be null
     * @param repeat    number of times to repeat str, negative treated as zero
     * @return a new String consisting of the original String repeated,
     * {@code null} if null String input
     * @since 2.5
     */
    public static String repeat(String str, String separator, int repeat) {
        if (str == null || separator == null) {
            return repeat(str, repeat);
        } else {
            // given that repeat(String, int) is quite optimized, better to rely
            // on it than try and splice this into it
            String result = repeat(str + separator, repeat);
            return removeEnd(result, separator);
        }
    }

    /**
     * <p>
     * Returns padding using the specified delimiter repeated to a given length.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.repeat(0, 'e')  = ""
     * StringUtils.repeat(3, 'e')  = "eee"
     * StringUtils.repeat(-2, 'e') = ""
     * </pre>
     * <p/>
     * <p>
     * Note: this method doesn't not support padding with <a
     * href="http://www.unicode.org/glossary/#supplementary_character">Unicode
     * Supplementary Characters</a> as they require a pair of {@code char}s to
     * be represented. If you are needing to support full I18N of your
     * applications consider using {@link #repeat(String, int)} instead.
     * </p>
     *
     * @param ch     character to repeat
     * @param repeat number of times to repeat char, negative treated as zero
     * @return String with repeated character
     * @see #repeat(String, int)
     */
    public static String repeat(char ch, int repeat) {
        char[] buf = new char[repeat];
        for (int i = repeat - 1; i >= 0; i--) {
            buf[i] = ch;
        }
        return new String(buf);
    }

    /**
     * <p>
     * Right pad a String with spaces (' ').
     * </p>
     * <p/>
     * <p>
     * The String is padded to the size of {@code size}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.rightPad(null, *)   = null
     * StringUtils.rightPad("", 3)     = "   "
     * StringUtils.rightPad("bat", 3)  = "bat"
     * StringUtils.rightPad("bat", 5)  = "bat  "
     * StringUtils.rightPad("bat", 1)  = "bat"
     * StringUtils.rightPad("bat", -1) = "bat"
     * </pre>
     *
     * @param str  the String to pad out, may be null
     * @param size the size to pad to
     * @return right padded String or original String if no padding is
     * necessary, {@code null} if null String input
     */
    public static String rightPad(String str, int size) {
        return rightPad(str, size, ' ');
    }

    /**
     * <p>
     * Right pad a String with a specified character.
     * </p>
     * <p/>
     * <p>
     * The String is padded to the size of {@code size}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.rightPad(null, *, *)     = null
     * StringUtils.rightPad("", 3, 'z')     = "zzz"
     * StringUtils.rightPad("bat", 3, 'z')  = "bat"
     * StringUtils.rightPad("bat", 5, 'z')  = "batzz"
     * StringUtils.rightPad("bat", 1, 'z')  = "bat"
     * StringUtils.rightPad("bat", -1, 'z') = "bat"
     * </pre>
     *
     * @param str     the String to pad out, may be null
     * @param size    the size to pad to
     * @param padChar the character to pad with
     * @return right padded String or original String if no padding is
     * necessary, {@code null} if null String input
     * @since 2.0
     */
    public static String rightPad(String str, int size, char padChar) {
        if (str == null) {
            return null;
        }
        int pads = size - str.length();
        if (pads <= 0) {
            return str;
        }
        if (pads > PAD_LIMIT) {
            return rightPad(str, size, String.valueOf(padChar));
        }
        return str.concat(repeat(padChar, pads));
    }

    /**
     * <p>
     * Right pad a String with a specified String.
     * </p>
     * <p/>
     * <p>
     * The String is padded to the size of {@code size}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.rightPad(null, *, *)      = null
     * StringUtils.rightPad("", 3, "z")      = "zzz"
     * StringUtils.rightPad("bat", 3, "yz")  = "bat"
     * StringUtils.rightPad("bat", 5, "yz")  = "batyz"
     * StringUtils.rightPad("bat", 8, "yz")  = "batyzyzy"
     * StringUtils.rightPad("bat", 1, "yz")  = "bat"
     * StringUtils.rightPad("bat", -1, "yz") = "bat"
     * StringUtils.rightPad("bat", 5, null)  = "bat  "
     * StringUtils.rightPad("bat", 5, "")    = "bat  "
     * </pre>
     *
     * @param str  the String to pad out, may be null
     * @param size the size to pad to
     * @param pad  the String to pad with, null or empty treated as single space
     * @return right padded String or original String if no padding is
     * necessary, {@code null} if null String input
     */
    public static String rightPad(String str, int size, String pad) {
        if (str == null) {
            return null;
        }
        String padStr = pad;
        if (isEmpty(padStr)) {
            padStr = " ";
        }
        int padLen = padStr.length();
        int strLen = str.length();
        int pads = size - strLen;
        if (pads <= 0) {
            return str;
        }
        if (padLen == 1 && pads <= PAD_LIMIT) {
            return rightPad(str, size, padStr.charAt(0));
        }

        if (pads == padLen) {
            return str.concat(padStr);
        } else if (pads < padLen) {
            return str.concat(padStr.substring(0, pads));
        } else {
            char[] padding = new char[pads];
            char[] padChars = padStr.toCharArray();
            for (int i = 0; i < pads; i++) {
                padding[i] = padChars[i % padLen];
            }
            return str.concat(new String(padding));
        }
    }

    /**
     * <p>
     * Left pad a String with spaces (' ').
     * </p>
     * <p/>
     * <p>
     * The String is padded to the size of {@code size}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.leftPad(null, *)   = null
     * StringUtils.leftPad("", 3)     = "   "
     * StringUtils.leftPad("bat", 3)  = "bat"
     * StringUtils.leftPad("bat", 5)  = "  bat"
     * StringUtils.leftPad("bat", 1)  = "bat"
     * StringUtils.leftPad("bat", -1) = "bat"
     * </pre>
     *
     * @param str  the String to pad out, may be null
     * @param size the size to pad to
     * @return left padded String or original String if no padding is necessary,
     * {@code null} if null String input
     */
    public static String leftPad(String str, int size) {
        return leftPad(str, size, ' ');
    }

    /**
     * <p>
     * Left pad a String with a specified character.
     * </p>
     * <p/>
     * <p>
     * Pad to a size of {@code size}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.leftPad(null, *, *)     = null
     * StringUtils.leftPad("", 3, 'z')     = "zzz"
     * StringUtils.leftPad("bat", 3, 'z')  = "bat"
     * StringUtils.leftPad("bat", 5, 'z')  = "zzbat"
     * StringUtils.leftPad("bat", 1, 'z')  = "bat"
     * StringUtils.leftPad("bat", -1, 'z') = "bat"
     * </pre>
     *
     * @param str     the String to pad out, may be null
     * @param size    the size to pad to
     * @param padChar the character to pad with
     * @return left padded String or original String if no padding is necessary,
     * {@code null} if null String input
     * @since 2.0
     */
    public static String leftPad(String str, int size, char padChar) {
        if (str == null) {
            return null;
        }
        int pads = size - str.length();
        if (pads <= 0) {
            return str;
        }
        if (pads > PAD_LIMIT) {
            return leftPad(str, size, String.valueOf(padChar));
        }
        return repeat(padChar, pads).concat(str);
    }

    /**
     * <p>
     * Left pad a String with a specified String.
     * </p>
     * <p/>
     * <p>
     * Pad to a size of {@code size}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.leftPad(null, *, *)      = null
     * StringUtils.leftPad("", 3, "z")      = "zzz"
     * StringUtils.leftPad("bat", 3, "yz")  = "bat"
     * StringUtils.leftPad("bat", 5, "yz")  = "yzbat"
     * StringUtils.leftPad("bat", 8, "yz")  = "yzyzybat"
     * StringUtils.leftPad("bat", 1, "yz")  = "bat"
     * StringUtils.leftPad("bat", -1, "yz") = "bat"
     * StringUtils.leftPad("bat", 5, null)  = "  bat"
     * StringUtils.leftPad("bat", 5, "")    = "  bat"
     * </pre>
     *
     * @param str  the String to pad out, may be null
     * @param size the size to pad to
     * @param pad  the String to pad with, null or empty treated as single space
     * @return left padded String or original String if no padding is necessary,
     * {@code null} if null String input
     */
    public static String leftPad(String str, int size, String pad) {
        if (str == null) {
            return null;
        }
        String padStr = pad;
        if (isEmpty(padStr)) {
            padStr = " ";
        }
        int padLen = padStr.length();
        int strLen = str.length();
        int pads = size - strLen;
        if (pads <= 0) {
            return str;
        }
        if (padLen == 1 && pads <= PAD_LIMIT) {
            return leftPad(str, size, padStr.charAt(0));
        }

        if (pads == padLen) {
            return padStr.concat(str);
        } else if (pads < padLen) {
            return padStr.substring(0, pads).concat(str);
        } else {
            char[] padding = new char[pads];
            char[] padChars = padStr.toCharArray();
            for (int i = 0; i < pads; i++) {
                padding[i] = padChars[i % padLen];
            }
            return new String(padding).concat(str);
        }
    }

    /**
     * Gets a CharSequence length or {@code 0} if the CharSequence is
     * {@code null}.
     *
     * @param cs a CharSequence or {@code null}
     * @return CharSequence length or {@code 0} if the CharSequence is
     * {@code null}.
     * @since 3.0 Changed signature from length(String) to length(CharSequence)
     */
    public static int length(CharSequence cs) {
        return cs == null ? 0 : cs.length();
    }

    /**
     * <p>
     * Centers a String in a larger String of size {@code size} using the space
     * character (' ').
     * <p>
     * <p/>
     * <p>
     * If the size is less than the String length, the String is returned. A
     * {@code null} String returns {@code null}. A negative size is treated as
     * zero.
     * </p>
     * <p/>
     * <p>
     * Equivalent to {@code center(str, size, " ")}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.center(null, *)   = null
     * StringUtils.center("", 4)     = "    "
     * StringUtils.center("ab", -1)  = "ab"
     * StringUtils.center("ab", 4)   = " ab "
     * StringUtils.center("abcd", 2) = "abcd"
     * StringUtils.center("a", 4)    = " a  "
     * </pre>
     *
     * @param str  the String to center, may be null
     * @param size the int size of new String, negative treated as zero
     * @return centered String, {@code null} if null String input
     */
    public static String center(String str, int size) {
        return center(str, size, ' ');
    }

    /**
     * <p>
     * Centers a String in a larger String of size {@code size}. Uses a supplied
     * character as the value to pad the String with.
     * </p>
     * <p/>
     * <p>
     * If the size is less than the String length, the String is returned. A
     * {@code null} String returns {@code null}. A negative size is treated as
     * zero.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.center(null, *, *)     = null
     * StringUtils.center("", 4, ' ')     = "    "
     * StringUtils.center("ab", -1, ' ')  = "ab"
     * StringUtils.center("ab", 4, ' ')   = " ab"
     * StringUtils.center("abcd", 2, ' ') = "abcd"
     * StringUtils.center("a", 4, ' ')    = " a  "
     * StringUtils.center("a", 4, 'y')    = "yayy"
     * </pre>
     *
     * @param string  the String to center, may be null
     * @param size    the int size of new String, negative treated as zero
     * @param padChar the character to pad the new String with
     * @return centered String, {@code null} if null String input
     * @since 2.0
     */
    public static String center(String string, int size, char padChar) {
        String str = string;
        if (str == null || size <= 0) {
            return str;
        }
        int strLen = str.length();
        int pads = size - strLen;
        if (pads <= 0) {
            return str;
        }
        str = leftPad(str, strLen + pads / CommonPlatformConstant.LENGTH_2, padChar);
        str = rightPad(str, size, padChar);
        return str;
    }

    /**
     * <p>
     * Centers a String in a larger String of size {@code size}. Uses a supplied
     * String as the value to pad the String with.
     * </p>
     * <p/>
     * <p>
     * If the size is less than the String length, the String is returned. A
     * {@code null} String returns {@code null}. A negative size is treated as
     * zero.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.center(null, *, *)     = null
     * StringUtils.center("", 4, " ")     = "    "
     * StringUtils.center("ab", -1, " ")  = "ab"
     * StringUtils.center("ab", 4, " ")   = " ab"
     * StringUtils.center("abcd", 2, " ") = "abcd"
     * StringUtils.center("a", 4, " ")    = " a  "
     * StringUtils.center("a", 4, "yz")   = "yayz"
     * StringUtils.center("abc", 7, null) = "  abc  "
     * StringUtils.center("abc", 7, "")   = "  abc  "
     * </pre>
     *
     * @param string the String to center, may be null
     * @param size   the int size of new String, negative treated as zero
     * @param pad    the String to pad the new String with, must not be null or
     *               empty
     * @return centered String, {@code null} if null String input
     * @throws IllegalArgumentException if padStr is {@code null} or empty
     */
    public static String center(String string, int size, String pad) {
        String str = string;
        if (str == null || size <= 0) {
            return str;
        }
        String padStr = pad;
        if (isEmpty(padStr)) {
            padStr = " ";
        }
        int strLen = str.length();
        int pads = size - strLen;
        if (pads <= 0) {
            return str;
        }
        str = leftPad(str, strLen + pads / CommonPlatformConstant.LENGTH_2, padStr);
        str = rightPad(str, size, padStr);
        return str;
    }

    /**
     * <p>
     * Converts a String to upper case as per {@link String#toUpperCase()}.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.upperCase(null)  = null
     * StringUtils.upperCase("")    = ""
     * StringUtils.upperCase("aBc") = "ABC"
     * </pre>
     * <p/>
     * <p>
     * <strong>Note:</strong> As described in the documentation for
     * {@link String#toUpperCase()}, the result of this method is affected by
     * the current locale. For platform-independent case transformations, the
     * method {@link #lowerCase(String, Locale)} should be used with a specific
     * locale (e.g. {@link Locale#ENGLISH}).
     * </p>
     *
     * @param str the String to upper case, may be null
     * @return the upper cased String, {@code null} if null String input
     */
    public static String upperCase(String str) {
        if (str == null) {
            return null;
        }
        return str.toUpperCase();
    }

    /**
     * <p>
     * Converts a String to upper case as per {@link String#toUpperCase(Locale)}
     * .
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.upperCase(null, Locale.ENGLISH)  = null
     * StringUtils.upperCase("", Locale.ENGLISH)    = ""
     * StringUtils.upperCase("aBc", Locale.ENGLISH) = "ABC"
     * </pre>
     *
     * @param str    the String to upper case, may be null
     * @param locale the locale that defines the case transformation rules, must
     *               not be null
     * @return the upper cased String, {@code null} if null String input
     * @since 2.5
     */
    public static String upperCase(String str, Locale locale) {
        if (str == null) {
            return null;
        }
        return str.toUpperCase(locale);
    }

    /**
     * <p>
     * Converts a String to lower case as per {@link String#toLowerCase()}.
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.lowerCase(null)  = null
     * StringUtils.lowerCase("")    = ""
     * StringUtils.lowerCase("aBc") = "abc"
     * </pre>
     * <p/>
     * <p>
     * <strong>Note:</strong> As described in the documentation for
     * {@link String#toLowerCase()}, the result of this method is affected by
     * the current locale. For platform-independent case transformations, the
     * method {@link #lowerCase(String, Locale)} should be used with a specific
     * locale (e.g. {@link Locale#ENGLISH}).
     * </p>
     *
     * @param str the String to lower case, may be null
     * @return the lower cased String, {@code null} if null String input
     */
    public static String lowerCase(String str) {
        if (str == null) {
            return null;
        }
        return str.toLowerCase();
    }

    /**
     * <p>
     * Converts a String to lower case as per {@link String#toLowerCase(Locale)}
     * .
     * </p>
     * <p/>
     * <p>
     * A {@code null} input String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.lowerCase(null, Locale.ENGLISH)  = null
     * StringUtils.lowerCase("", Locale.ENGLISH)    = ""
     * StringUtils.lowerCase("aBc", Locale.ENGLISH) = "abc"
     * </pre>
     *
     * @param str    the String to lower case, may be null
     * @param locale the locale that defines the case transformation rules, must
     *               not be null
     * @return the lower cased String, {@code null} if null String input
     * @since 2.5
     */
    public static String lowerCase(String str, Locale locale) {
        if (str == null) {
            return null;
        }
        return str.toLowerCase(locale);
    }

    /**
     * <p>
     * Capitalizes a String changing the first letter to title case as per
     * {@link Character#toTitleCase(char)}. No other letters are changed.
     * </p>
     * <p/>
     * <p>
     * For a word based algorithm, see
     * {@link org.apache.commons.lang3.text.WordUtils#capitalize(String)}. A
     * {@code null} input String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.capitalize(null)  = null
     * StringUtils.capitalize("")    = ""
     * StringUtils.capitalize("cat") = "Cat"
     * StringUtils.capitalize("cAt") = "CAt"
     * </pre>
     *
     * @param str the String to capitalize, may be null
     * @return the capitalized String, {@code null} if null String input
     * @see org.apache.commons.lang3.text.WordUtils#capitalize(String)
     * @see #uncapitalize(String)
     * @since 2.0
     */
    public static String capitalize(String str) {
        int strLen;
        if (str == null || (strLen = str.length()) == 0) {
            return str;
        }
        return new StringBuilder(strLen).append(Character.toTitleCase(str.charAt(0))).append(str.substring(1))
                .toString();
    }

    /**
     * <p>
     * Uncapitalizes a String changing the first letter to title case as per
     * {@link Character#toLowerCase(char)}. No other letters are changed.
     * </p>
     * <p/>
     * <p>
     * For a word based algorithm, see
     * {@link org.apache.commons.lang3.text.WordUtils#uncapitalize(String)}. A
     * {@code null} input String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.uncapitalize(null)  = null
     * StringUtils.uncapitalize("")    = ""
     * StringUtils.uncapitalize("Cat") = "cat"
     * StringUtils.uncapitalize("CAT") = "cAT"
     * </pre>
     *
     * @param str the String to uncapitalize, may be null
     * @return the uncapitalized String, {@code null} if null String input
     * @see org.apache.commons.lang3.text.WordUtils#uncapitalize(String)
     * @see #capitalize(String)
     * @since 2.0
     */
    public static String uncapitalize(String str) {
        int strLen;
        if (str == null || (strLen = str.length()) == 0) {
            return str;
        }
        return new StringBuilder(strLen).append(Character.toLowerCase(str.charAt(0))).append(str.substring(1))
                .toString();
    }

    /**
     * <p>
     * Swaps the case of a String changing upper and title case to lower case,
     * and lower case to upper case.
     * </p>
     * <p/>
     * <ul>
     * <li>Upper case character converts to Lower case</li>
     * <li>Title case character converts to Lower case</li>
     * <li>Lower case character converts to Upper case</li>
     * </ul>
     * <p/>
     * <p>
     * For a word based algorithm, see
     * {@link org.apache.commons.lang3.text.WordUtils#swapCase(String)}. A
     * {@code null} input String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.swapCase(null)                 = null
     * StringUtils.swapCase("")                   = ""
     * StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"
     * </pre>
     * <p/>
     * <p>
     * NOTE: This method changed in Lang version 2.0. It no longer performs a
     * word based algorithm. If you only use ASCII, you will notice no change.
     * That functionality is available in
     * org.apache.commons.lang3.text.WordUtils.
     * </p>
     *
     * @param str the String to swap case, may be null
     * @return the changed String, {@code null} if null String input
     */
    public static String swapCase(String str) {
        if (StringUtils.isEmpty(str)) {
            return str;
        }

        char[] buffer = str.toCharArray();

        for (int i = 0; i < buffer.length; i++) {
            char ch = buffer[i];
            if (Character.isUpperCase(ch)) {
                buffer[i] = Character.toLowerCase(ch);
            } else if (Character.isTitleCase(ch)) {
                buffer[i] = Character.toLowerCase(ch);
            } else if (Character.isLowerCase(ch)) {
                buffer[i] = Character.toUpperCase(ch);
            }
        }
        return new String(buffer);
    }

    /**
     * <p>
     * Counts how many times the substring appears in the larger string.
     * </p>
     * <p/>
     * <p>
     * A {@code null} or empty ("") String input returns {@code 0}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.countMatches(null, *)       = 0
     * StringUtils.countMatches("", *)         = 0
     * StringUtils.countMatches("abba", null)  = 0
     * StringUtils.countMatches("abba", "")    = 0
     * StringUtils.countMatches("abba", "a")   = 2
     * StringUtils.countMatches("abba", "ab")  = 1
     * StringUtils.countMatches("abba", "xxx") = 0
     * </pre>
     *
     * @param str the CharSequence to check, may be null
     * @param sub the substring to count, may be null
     * @return the number of occurrences, 0 if either CharSequence is
     * {@code null}
     * @since 3.0 Changed signature from countMatches(String, String) to
     * countMatches(CharSequence, CharSequence)
     */
    public static int countMatches(CharSequence str, CharSequence sub) {
        if (isEmpty(str) || isEmpty(sub)) {
            return 0;
        }
        int count = 0;
        int idx = 0;
        while ((idx = CharSequenceUtils.indexOf(str, sub, idx)) != INDEX_NOT_FOUND) {
            count++;
            idx += sub.length();
        }
        return count;
    }

    /**
     * <p>
     * Checks if the CharSequence contains only Unicode letters.
     * </p>
     * <p/>
     * <p>
     * {@code null} will return {@code false}. An empty CharSequence
     * (length()=0) will return {@code false}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isAlpha(null)   = false
     * StringUtils.isAlpha("")     = false
     * StringUtils.isAlpha("  ")   = false
     * StringUtils.isAlpha("abc")  = true
     * StringUtils.isAlpha("ab2c") = false
     * StringUtils.isAlpha("ab-c") = false
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if only contains letters, and is non-null
     * @since 3.0 Changed "" to return false and not true
     */
    public static boolean isAlpha(CharSequence cs) {
        if (cs == null || cs.length() == 0) {
            return false;
        }
        int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (!Character.isLetter(cs.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * <p>
     * Checks if the CharSequence contains only Unicode letters and space (' ').
     * </p>
     * <p/>
     * <p>
     * {@code null} will return {@code false} An empty CharSequence (length()=0)
     * will return {@code true}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isAlphaSpace(null)   = false
     * StringUtils.isAlphaSpace("")     = true
     * StringUtils.isAlphaSpace("  ")   = true
     * StringUtils.isAlphaSpace("abc")  = true
     * StringUtils.isAlphaSpace("ab c") = true
     * StringUtils.isAlphaSpace("ab2c") = false
     * StringUtils.isAlphaSpace("ab-c") = false
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if only contains letters and space, and is non-null
     * @since 3.0 Changed signature from isAlphaSpace(String) to
     * isAlphaSpace(CharSequence)
     */
    public static boolean isAlphaSpace(CharSequence cs) {
        if (cs == null) {
            return false;
        }
        int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (!Character.isLetter(cs.charAt(i)) && cs.charAt(i) != ' ') {
                return false;
            }
        }
        return true;
    }

    /**
     * <p>
     * Checks if the CharSequence contains only Unicode letters or digits.
     * </p>
     * <p/>
     * <p>
     * {@code null} will return {@code false}. An empty CharSequence
     * (length()=0) will return {@code false}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isAlphanumeric(null)   = false
     * StringUtils.isAlphanumeric("")     = false
     * StringUtils.isAlphanumeric("  ")   = false
     * StringUtils.isAlphanumeric("abc")  = true
     * StringUtils.isAlphanumeric("ab c") = false
     * StringUtils.isAlphanumeric("ab2c") = true
     * StringUtils.isAlphanumeric("ab-c") = false
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if only contains letters or digits, and is non-null
     * @since 3.0 Changed "" to return false and not true
     */
    public static boolean isAlphanumeric(CharSequence cs) {
        if (cs == null || cs.length() == 0) {
            return false;
        }
        int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (!Character.isLetterOrDigit(cs.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * <p>
     * Checks if the CharSequence contains only Unicode letters, digits or space
     * ({@code ' '}).
     * </p>
     * <p/>
     * <p>
     * {@code null} will return {@code false}. An empty CharSequence
     * (length()=0) will return {@code true}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isAlphanumericSpace(null)   = false
     * StringUtils.isAlphanumericSpace("")     = true
     * StringUtils.isAlphanumericSpace("  ")   = true
     * StringUtils.isAlphanumericSpace("abc")  = true
     * StringUtils.isAlphanumericSpace("ab c") = true
     * StringUtils.isAlphanumericSpace("ab2c") = true
     * StringUtils.isAlphanumericSpace("ab-c") = false
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if only contains letters, digits or space, and is
     * non-null
     * @since 3.0 Changed signature from isAlphanumericSpace(String) to
     * isAlphanumericSpace(CharSequence)
     */
    public static boolean isAlphanumericSpace(CharSequence cs) {
        if (cs == null) {
            return false;
        }
        int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (!Character.isLetterOrDigit(cs.charAt(i)) && cs.charAt(i) != ' ') {
                return false;
            }
        }
        return true;
    }

    /**
     * <p>
     * Checks if the CharSequence contains only ASCII printable characters.
     * </p>
     * <p/>
     * <p>
     * {@code null} will return {@code false}. An empty CharSequence
     * (length()=0) will return {@code true}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isAsciiPrintable(null)     = false
     * StringUtils.isAsciiPrintable("")       = true
     * StringUtils.isAsciiPrintable(" ")      = true
     * StringUtils.isAsciiPrintable("Ceki")   = true
     * StringUtils.isAsciiPrintable("ab2c")   = true
     * StringUtils.isAsciiPrintable("!ab-c~") = true
     * StringUtils.isAsciiPrintable("\u0020") = true
     * StringUtils.isAsciiPrintable("\u0021") = true
     * StringUtils.isAsciiPrintable("\u007e") = true
     * StringUtils.isAsciiPrintable("\u007f") = false
     * StringUtils.isAsciiPrintable("Ceki G\u00fclc\u00fc") = false
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if every character is in the range 32 thru 126
     * @since 3.0 Changed signature from isAsciiPrintable(String) to
     * isAsciiPrintable(CharSequence)
     */
    public static boolean isAsciiPrintable(CharSequence cs) {
        if (cs == null) {
            return false;
        }
        int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (!CharUtils.isAsciiPrintable(cs.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * <p>
     * Checks if the CharSequence contains only Unicode digits. A decimal point
     * is not a Unicode digit and returns false.
     * </p>
     * <p/>
     * <p>
     * {@code null} will return {@code false}. An empty CharSequence
     * (length()=0) will return {@code false}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isNumeric(null)   = false
     * StringUtils.isNumeric("")     = false
     * StringUtils.isNumeric("  ")   = false
     * StringUtils.isNumeric("123")  = true
     * StringUtils.isNumeric("12 3") = false
     * StringUtils.isNumeric("ab2c") = false
     * StringUtils.isNumeric("12-3") = false
     * StringUtils.isNumeric("12.3") = false
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if only contains digits, and is non-null
     * @since 3.0 Changed "" to return false and not true
     */
    public static boolean isNumeric(CharSequence cs) {
        if (cs == null || cs.length() == 0) {
            return false;
        }
        int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (!Character.isDigit(cs.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * <p>
     * Checks if the CharSequence contains only Unicode digits or space (
     * {@code ' '}). A decimal point is not a Unicode digit and returns false.
     * </p>
     * <p/>
     * <p>
     * {@code null} will return {@code false}. An empty CharSequence
     * (length()=0) will return {@code true}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isNumericSpace(null)   = false
     * StringUtils.isNumericSpace("")     = true
     * StringUtils.isNumericSpace("  ")   = true
     * StringUtils.isNumericSpace("123")  = true
     * StringUtils.isNumericSpace("12 3") = true
     * StringUtils.isNumericSpace("ab2c") = false
     * StringUtils.isNumericSpace("12-3") = false
     * StringUtils.isNumericSpace("12.3") = false
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if only contains digits or space, and is non-null
     * @since 3.0 Changed signature from isNumericSpace(String) to
     * isNumericSpace(CharSequence)
     */
    public static boolean isNumericSpace(CharSequence cs) {
        if (cs == null) {
            return false;
        }
        int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (!Character.isDigit(cs.charAt(i)) && cs.charAt(i) != ' ') {
                return false;
            }
        }
        return true;
    }

    /**
     * <p>
     * Checks if the CharSequence contains only whitespace.
     * </p>
     * <p/>
     * <p>
     * {@code null} will return {@code false}. An empty CharSequence
     * (length()=0) will return {@code true}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isWhitespace(null)   = false
     * StringUtils.isWhitespace("")     = true
     * StringUtils.isWhitespace("  ")   = true
     * StringUtils.isWhitespace("abc")  = false
     * StringUtils.isWhitespace("ab2c") = false
     * StringUtils.isWhitespace("ab-c") = false
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if only contains whitespace, and is non-null
     * @since 3.0 Changed signature from isWhitespace(String) to
     * isWhitespace(CharSequence)
     */
    public static boolean isWhitespace(CharSequence cs) {
        if (cs == null) {
            return false;
        }
        int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (!Character.isWhitespace(cs.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * <p>
     * Checks if the CharSequence contains only lowercase characters.
     * </p>
     * <p/>
     * <p>
     * {@code null} will return {@code false}. An empty CharSequence
     * (length()=0) will return {@code false}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isAllLowerCase(null)   = false
     * StringUtils.isAllLowerCase("")     = false
     * StringUtils.isAllLowerCase("  ")   = false
     * StringUtils.isAllLowerCase("abc")  = true
     * StringUtils.isAllLowerCase("abC") = false
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if only contains lowercase characters, and is
     * non-null
     * @since 3.0 Changed signature from isAllLowerCase(String) to
     * isAllLowerCase(CharSequence)
     */
    public static boolean isAllLowerCase(CharSequence cs) {
        if (cs == null || isEmpty(cs)) {
            return false;
        }
        int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (!Character.isLowerCase(cs.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * <p>
     * Checks if the CharSequence contains only uppercase characters.
     * </p>
     * <p/>
     * <p>
     * {@code null} will return {@code false}. An empty String (length()=0) will
     * return {@code false}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.isAllUpperCase(null)   = false
     * StringUtils.isAllUpperCase("")     = false
     * StringUtils.isAllUpperCase("  ")   = false
     * StringUtils.isAllUpperCase("ABC")  = true
     * StringUtils.isAllUpperCase("aBC") = false
     * </pre>
     *
     * @param cs the CharSequence to check, may be null
     * @return {@code true} if only contains uppercase characters, and is
     * non-null
     * @since 3.0 Changed signature from isAllUpperCase(String) to
     * isAllUpperCase(CharSequence)
     */
    public static boolean isAllUpperCase(CharSequence cs) {
        if (cs == null || isEmpty(cs)) {
            return false;
        }
        int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (!Character.isUpperCase(cs.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * <p>
     * Returns either the passed in String, or if the String is {@code null}, an
     * empty String ("").
     * </p>
     * <p/>
     * <pre>
     * StringUtils.defaultString(null)  = ""
     * StringUtils.defaultString("")    = ""
     * StringUtils.defaultString("bat") = "bat"
     * </pre>
     *
     * @param str the String to check, may be null
     * @return the passed in String, or the empty String if it was {@code null}
     * @see String#valueOf(Object)
     */
    public static String defaultString(String str) {
        return str == null ? EMPTY : str;
    }

    /**
     * <p>
     * Returns either the passed in String, or if the String is {@code null},
     * the value of {@code defaultStr}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.defaultString(null, "NULL")  = "NULL"
     * StringUtils.defaultString("", "NULL")    = ""
     * StringUtils.defaultString("bat", "NULL") = "bat"
     * </pre>
     *
     * @param str        the String to check, may be null
     * @param defaultStr the default String to return if the input is {@code null}, may
     *                   be null
     * @return the passed in String, or the default if it was {@code null}
     * @see String#valueOf(Object)
     */
    public static String defaultString(String str, String defaultStr) {
        return str == null ? defaultStr : str;
    }

    /**
     * <p>
     * Returns either the passed in CharSequence, or if the CharSequence is
     * whitespace, empty ("") or {@code null}, the value of {@code defaultStr}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.defaultIfBlank(null, "NULL")  = "NULL"
     * StringUtils.defaultIfBlank("", "NULL")    = "NULL"
     * StringUtils.defaultIfBlank(" ", "NULL")   = "NULL"
     * StringUtils.defaultIfBlank("bat", "NULL") = "bat"
     * StringUtils.defaultIfBlank("", null)      = null
     * </pre>
     *
     * @param <T>        the specific kind of CharSequence
     * @param str        the CharSequence to check, may be null
     * @param defaultStr the default CharSequence to return if the input is whitespace,
     *                   empty ("") or {@code null}, may be null
     * @return the passed in CharSequence, or the default
     * @see StringUtils#defaultString(String, String)
     */
    public static <T extends CharSequence> T defaultIfBlank(T str, T defaultStr) {
        return StringUtils.isBlank(str) ? defaultStr : str;
    }

    /**
     * <p>
     * Returns either the passed in CharSequence, or if the CharSequence is
     * empty or {@code null}, the value of {@code defaultStr}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.defaultIfEmpty(null, "NULL")  = "NULL"
     * StringUtils.defaultIfEmpty("", "NULL")    = "NULL"
     * StringUtils.defaultIfEmpty(" ", "NULL")   = " "
     * StringUtils.defaultIfEmpty("bat", "NULL") = "bat"
     * StringUtils.defaultIfEmpty("", null)      = null
     * </pre>
     *
     * @param <T>        the specific kind of CharSequence
     * @param str        the CharSequence to check, may be null
     * @param defaultStr the default CharSequence to return if the input is empty ("")
     *                   or {@code null}, may be null
     * @return the passed in CharSequence, or the default
     * @see StringUtils#defaultString(String, String)
     */
    public static <T extends CharSequence> T defaultIfEmpty(T str, T defaultStr) {
        return StringUtils.isEmpty(str) ? defaultStr : str;
    }

    /**
     * <p>
     * Reverses a String as per {@link StringBuilder#reverse()}.
     * </p>
     * <p/>
     * <p>
     * A {@code null} String returns {@code null}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.reverse(null)  = null
     * StringUtils.reverse("")    = ""
     * StringUtils.reverse("bat") = "tab"
     * </pre>
     *
     * @param str the String to reverse, may be null
     * @return the reversed String, {@code null} if null String input
     */
    public static String reverse(String str) {
        if (str == null) {
            return null;
        }
        return new StringBuilder(str).reverse().toString();
    }

    /**
     * <p>
     * Reverses a String that is delimited by a specific character.
     * </p>
     * <p/>
     * <p>
     * The Strings between the delimiters are not reversed. Thus
     * java.lang.String becomes String.lang.java (if the delimiter is
     * {@code '.'}).
     * </p>
     * <p/>
     * <pre>
     * StringUtils.reverseDelimited(null, *)      = null
     * StringUtils.reverseDelimited("", *)        = ""
     * StringUtils.reverseDelimited("a.b.c", 'x') = "a.b.c"
     * StringUtils.reverseDelimited("a.b.c", ".") = "c.b.a"
     * </pre>
     *
     * @param str           the String to reverse, may be null
     * @param separatorChar the separator character to use
     * @return the reversed String, {@code null} if null String input
     * @since 2.0
     */
    public static String reverseDelimited(String str, char separatorChar) {
        if (str == null) {
            return null;
        }
        // could implement manually, but simple way is to reuse other,
        // probably slower, methods.
        String[] strs = split(str, separatorChar);

        int i = 0;
        int j = strs.length - 1;
        String tmp;
        while (j > i) {
            tmp = strs[j];
            strs[j] = strs[i];
            strs[i] = tmp;
            j--;
            i++;
        }

        return join(strs, separatorChar);
    }

    /**
     * <p>
     * Abbreviates a String using ellipses. This will turn
     * "Now is the time for all good men" into "Now is the time for..."
     * </p>
     * <p/>
     * <p>
     * Specifically:
     * <ul>
     * <li>If {@code str} is less than {@code maxWidth} characters long, return
     * it.</li>
     * <li>Else abbreviate it to {@code (substring(str, 0, max-3) + "...")}.</li>
     * <li>If {@code maxWidth} is less than {@code 4}, throw an
     * {@code IllegalArgumentException}.</li>
     * <li>In no case will it return a String of length greater than
     * {@code maxWidth}.</li>
     * </ul>
     * </p>
     * <p/>
     * <pre>
     * StringUtils.abbreviate(null, *)      = null
     * StringUtils.abbreviate("", 4)        = ""
     * StringUtils.abbreviate("abcdefg", 6) = "abc..."
     * StringUtils.abbreviate("abcdefg", 7) = "abcdefg"
     * StringUtils.abbreviate("abcdefg", 8) = "abcdefg"
     * StringUtils.abbreviate("abcdefg", 4) = "a..."
     * StringUtils.abbreviate("abcdefg", 3) = IllegalArgumentException
     * </pre>
     *
     * @param str      the String to check, may be null
     * @param maxWidth maximum length of result String, must be at least 4
     * @return abbreviated String, {@code null} if null String input
     * @throws IllegalArgumentException if the width is too small
     * @since 2.0
     */
    public static String abbreviate(String str, int maxWidth) {
        return abbreviate(str, 0, maxWidth);
    }

    /**
     * <p>
     * Abbreviates a String using ellipses. This will turn
     * "Now is the time for all good men" into "...is the time for..."
     * </p>
     * <p/>
     * <p>
     * Works like {@code abbreviate(String, int)}, but allows you to specify a
     * "left edge" offset. Note that this left edge is not necessarily going to
     * be the leftmost character in the result, or the first character following
     * the ellipses, but it will appear somewhere in the result.
     * <p/>
     * <p>
     * In no case will it return a String of length greater than
     * {@code maxWidth}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.abbreviate(null, *, *)                = null
     * StringUtils.abbreviate("", 0, 4)                  = ""
     * StringUtils.abbreviate("abcdefghijklmno", -1, 10) = "abcdefg..."
     * StringUtils.abbreviate("abcdefghijklmno", 0, 10)  = "abcdefg..."
     * StringUtils.abbreviate("abcdefghijklmno", 1, 10)  = "abcdefg..."
     * StringUtils.abbreviate("abcdefghijklmno", 4, 10)  = "abcdefg..."
     * StringUtils.abbreviate("abcdefghijklmno", 5, 10)  = "...fghi..."
     * StringUtils.abbreviate("abcdefghijklmno", 6, 10)  = "...ghij..."
     * StringUtils.abbreviate("abcdefghijklmno", 8, 10)  = "...ijklmno"
     * StringUtils.abbreviate("abcdefghijklmno", 10, 10) = "...ijklmno"
     * StringUtils.abbreviate("abcdefghijklmno", 12, 10) = "...ijklmno"
     * StringUtils.abbreviate("abcdefghij", 0, 3)        = IllegalArgumentException
     * StringUtils.abbreviate("abcdefghij", 5, 6)        = IllegalArgumentException
     * </pre>
     *
     * @param str      the String to check, may be null
     * @param start    left edge of source String
     * @param maxWidth maximum length of result String, must be at least 4
     * @return abbreviated String, {@code null} if null String input
     * @throws IllegalArgumentException if the width is too small
     * @since 2.0
     */
    public static String abbreviate(String str, int start, int maxWidth) {
        if (str == null) {
            return null;
        }
        if (maxWidth < CommonPlatformConstant.LENGTH_4) {
            throw new IllegalArgumentException("Minimum abbreviation width is 4");
        }
        if (str.length() <= maxWidth) {
            return str;
        }
        int offset = start;
        if (offset > str.length()) {
            offset = str.length();
        }
        if (str.length() - offset < maxWidth - CommonPlatformConstant.LENGTH_3) {
            offset = str.length() - (maxWidth - CommonPlatformConstant.LENGTH_3);
        }
        final String abrevMarker = "...";
        if (offset <= CommonPlatformConstant.LENGTH_4) {
            return str.substring(0, maxWidth - CommonPlatformConstant.LENGTH_3) + abrevMarker;
        }
        if (maxWidth < CommonPlatformConstant.LENGTH_7) {
            throw new IllegalArgumentException("Minimum abbreviation width with offset is 7");
        }
        if (offset + maxWidth - CommonPlatformConstant.LENGTH_3 < str.length()) {
            return abrevMarker + abbreviate(str.substring(offset), maxWidth - CommonPlatformConstant.LENGTH_3);
        }
        return abrevMarker + str.substring(str.length() - (maxWidth - CommonPlatformConstant.LENGTH_3));
    }

    /**
     * <p>
     * Abbreviates a String to the length passed, replacing the middle
     * characters with the supplied replacement String.
     * </p>
     * <p/>
     * <p>
     * This abbreviation only occurs if the following criteria is met:
     * <ul>
     * <li>Neither the String for abbreviation nor the replacement String are
     * null or empty</li>
     * <li>The length to truncate to is less than the length of the supplied
     * String</li>
     * <li>The length to truncate to is greater than 0</li>
     * <li>The abbreviated String will have enough room for the length supplied
     * replacement String and the first and last characters of the supplied
     * String for abbreviation</li>
     * </ul>
     * Otherwise, the returned String will be the same as the supplied String
     * for abbreviation.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.abbreviateMiddle(null, null, 0)      = null
     * StringUtils.abbreviateMiddle("abc", null, 0)      = "abc"
     * StringUtils.abbreviateMiddle("abc", ".", 0)      = "abc"
     * StringUtils.abbreviateMiddle("abc", ".", 3)      = "abc"
     * StringUtils.abbreviateMiddle("abcdef", ".", 4)     = "ab.f"
     * </pre>
     *
     * @param str    the String to abbreviate, may be null
     * @param middle the String to replace the middle characters with, may be null
     * @param length the length to abbreviate {@code str} to.
     * @return the abbreviated String if the above criteria is met, or the
     * original String supplied for abbreviation.
     * @since 2.5
     */
    public static String abbreviateMiddle(String str, String middle, int length) {
        if (isEmpty(str) || isEmpty(middle)) {
            return str;
        }

        if (length >= str.length() || length < middle.length() + CommonPlatformConstant.LENGTH_2) {
            return str;
        }

        int targetSting = length - middle.length();
        int startOffset = targetSting / CommonPlatformConstant.LENGTH_2
                + targetSting % CommonPlatformConstant.LENGTH_2;
        int endOffset = str.length() - targetSting / CommonPlatformConstant.LENGTH_2;

        StringBuilder builder = new StringBuilder(length);
        builder.append(str.substring(0, startOffset));
        builder.append(middle);
        builder.append(str.substring(endOffset));

        return builder.toString();
    }

    /**
     * <p>
     * Compares two Strings, and returns the portion where they differ. (More
     * precisely, return the remainder of the second String, starting from where
     * it's different from the first.)
     * </p>
     * <p/>
     * <p>
     * For example,
     * {@code difference("i am a machine", "i am a robot") -> "robot"}.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.difference(null, null) = null
     * StringUtils.difference("", "") = ""
     * StringUtils.difference("", "abc") = "abc"
     * StringUtils.difference("abc", "") = ""
     * StringUtils.difference("abc", "abc") = ""
     * StringUtils.difference("ab", "abxyz") = "xyz"
     * StringUtils.difference("abcde", "abxyz") = "xyz"
     * StringUtils.difference("abcde", "xyz") = "xyz"
     * </pre>
     *
     * @param str1 the first String, may be null
     * @param str2 the second String, may be null
     * @return the portion of str2 where it differs from str1; returns the empty
     * String if they are equal
     * @since 2.0
     */
    public static String difference(String str1, String str2) {
        if (str1 == null) {
            return str2;
        }
        if (str2 == null) {
            return str1;
        }
        int at = indexOfDifference(str1, str2);
        if (at == INDEX_NOT_FOUND) {
            return EMPTY;
        }
        return str2.substring(at);
    }

    /**
     * <p>
     * Compares two CharSequences, and returns the index at which the
     * CharSequences begin to differ.
     * </p>
     * <p/>
     * <p>
     * For example,
     * {@code indexOfDifference("i am a machine", "i am a robot") -> 7}
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOfDifference(null, null) = -1
     * StringUtils.indexOfDifference("", "") = -1
     * StringUtils.indexOfDifference("", "abc") = 0
     * StringUtils.indexOfDifference("abc", "") = 0
     * StringUtils.indexOfDifference("abc", "abc") = -1
     * StringUtils.indexOfDifference("ab", "abxyz") = 2
     * StringUtils.indexOfDifference("abcde", "abxyz") = 2
     * StringUtils.indexOfDifference("abcde", "xyz") = 0
     * </pre>
     *
     * @param cs1 the first CharSequence, may be null
     * @param cs2 the second CharSequence, may be null
     * @return the index where cs1 and cs2 begin to differ; -1 if they are equal
     * @since 3.0 Changed signature from indexOfDifference(String, String) to
     * indexOfDifference(CharSequence, CharSequence)
     */
    public static int indexOfDifference(CharSequence cs1, CharSequence cs2) {
        if (cs1 == cs2) {
            return INDEX_NOT_FOUND;
        }
        if (cs1 == null || cs2 == null) {
            return 0;
        }
        int i;
        for (i = 0; i < cs1.length() && i < cs2.length(); ++i) {
            if (cs1.charAt(i) != cs2.charAt(i)) {
                break;
            }
        }
        if (i < cs2.length() || i < cs1.length()) {
            return i;
        }
        return INDEX_NOT_FOUND;
    }

    /**
     * <p>
     * Compares all CharSequences in an array and returns the index at which the
     * CharSequences begin to differ.
     * </p>
     * <p/>
     * <p>
     * For example,
     * <code>indexOfDifference(new String[] {"i am a machine", "i am a robot"}) -> 7</code>
     * </p>
     * <p/>
     * <pre>
     * StringUtils.indexOfDifference(null) = -1
     * StringUtils.indexOfDifference(new String[] {}) = -1
     * StringUtils.indexOfDifference(new String[] {"abc"}) = -1
     * StringUtils.indexOfDifference(new String[] {null, null}) = -1
     * StringUtils.indexOfDifference(new String[] {"", ""}) = -1
     * StringUtils.indexOfDifference(new String[] {"", null}) = 0
     * StringUtils.indexOfDifference(new String[] {"abc", null, null}) = 0
     * StringUtils.indexOfDifference(new String[] {null, null, "abc"}) = 0
     * StringUtils.indexOfDifference(new String[] {"", "abc"}) = 0
     * StringUtils.indexOfDifference(new String[] {"abc", ""}) = 0
     * StringUtils.indexOfDifference(new String[] {"abc", "abc"}) = -1
     * StringUtils.indexOfDifference(new String[] {"abc", "a"}) = 1
     * StringUtils.indexOfDifference(new String[] {"ab", "abxyz"}) = 2
     * StringUtils.indexOfDifference(new String[] {"abcde", "abxyz"}) = 2
     * StringUtils.indexOfDifference(new String[] {"abcde", "xyz"}) = 0
     * StringUtils.indexOfDifference(new String[] {"xyz", "abcde"}) = 0
     * StringUtils.indexOfDifference(new String[] {"i am a machine", "i am a robot"}) = 7
     * </pre>
     *
     * @param css array of CharSequences, entries may be null
     * @return the index where the strings begin to differ; -1 if they are all
     * equal
     * @since 3.0 Changed signature from indexOfDifference(String...) to
     * indexOfDifference(CharSequence...)
     */
    public static int indexOfDifference(CharSequence... css) {
        if (css == null || css.length <= 1) {
            return INDEX_NOT_FOUND;
        }
        boolean anyStringNull = false;
        boolean allStringsNull = true;
        int arrayLen = css.length;
        int shortestStrLen = Integer.MAX_VALUE;
        int longestStrLen = 0;

        // find the min and max string lengths; this avoids checking to make
        // sure we are not exceeding the length of the string each time through
        // the bottom loop.
        for (int i = 0; i < arrayLen; i++) {
            if (css[i] == null) {
                anyStringNull = true;
                shortestStrLen = 0;
            } else {
                allStringsNull = false;
                shortestStrLen = Math.min(css[i].length(), shortestStrLen);
                longestStrLen = Math.max(css[i].length(), longestStrLen);
            }
        }

        // handle lists containing all nulls or all empty strings
        if (allStringsNull || longestStrLen == 0 && !anyStringNull) {
            return INDEX_NOT_FOUND;
        }

        // handle lists containing some nulls or some empty strings
        if (shortestStrLen == 0) {
            return 0;
        }

        // find the position with the first difference across all strings
        int firstDiff = -1;
        for (int stringPos = 0; stringPos < shortestStrLen; stringPos++) {
            char comparisonChar = css[0].charAt(stringPos);
            for (int arrayPos = 1; arrayPos < arrayLen; arrayPos++) {
                if (css[arrayPos].charAt(stringPos) != comparisonChar) {
                    firstDiff = stringPos;
                    break;
                }
            }
            if (firstDiff != -1) {
                break;
            }
        }

        if (firstDiff == -1 && shortestStrLen != longestStrLen) {
            // we compared all of the characters up to the length of the
            // shortest string and didn't find a match, but the string lengths
            // vary, so return the length of the shortest string.
            return shortestStrLen;
        }
        return firstDiff;
    }

    /**
     * <p>
     * Compares all Strings in an array and returns the initial sequence of
     * characters that is common to all of them.
     * </p>
     * <p/>
     * <p>
     * For example,
     * <code>getCommonPrefix(new String[] {"i am a machine", "i am a robot"}) -> "i am a "</code>
     * </p>
     * <p/>
     * <pre>
     * StringUtils.getCommonPrefix(null) = ""
     * StringUtils.getCommonPrefix(new String[] {}) = ""
     * StringUtils.getCommonPrefix(new String[] {"abc"}) = "abc"
     * StringUtils.getCommonPrefix(new String[] {null, null}) = ""
     * StringUtils.getCommonPrefix(new String[] {"", ""}) = ""
     * StringUtils.getCommonPrefix(new String[] {"", null}) = ""
     * StringUtils.getCommonPrefix(new String[] {"abc", null, null}) = ""
     * StringUtils.getCommonPrefix(new String[] {null, null, "abc"}) = ""
     * StringUtils.getCommonPrefix(new String[] {"", "abc"}) = ""
     * StringUtils.getCommonPrefix(new String[] {"abc", ""}) = ""
     * StringUtils.getCommonPrefix(new String[] {"abc", "abc"}) = "abc"
     * StringUtils.getCommonPrefix(new String[] {"abc", "a"}) = "a"
     * StringUtils.getCommonPrefix(new String[] {"ab", "abxyz"}) = "ab"
     * StringUtils.getCommonPrefix(new String[] {"abcde", "abxyz"}) = "ab"
     * StringUtils.getCommonPrefix(new String[] {"abcde", "xyz"}) = ""
     * StringUtils.getCommonPrefix(new String[] {"xyz", "abcde"}) = ""
     * StringUtils.getCommonPrefix(new String[] {"i am a machine", "i am a robot"}) = "i am a "
     * </pre>
     *
     * @param strs array of String objects, entries may be null
     * @return the initial sequence of characters that are common to all Strings
     * in the array; empty String if the array is null, the elements are
     * all null or if there is no common prefix.
     * @since 2.4
     */
    public static String getCommonPrefix(String... strs) {
        if (strs == null || strs.length == 0) {
            return EMPTY;
        }
        int smallestIndexOfDiff = indexOfDifference(strs);
        if (smallestIndexOfDiff == INDEX_NOT_FOUND) {
            // all strings were identical
            if (strs[0] == null) {
                return EMPTY;
            }
            return strs[0];
        } else if (smallestIndexOfDiff == 0) {
            // there were no common initial characters
            return EMPTY;
        } else {
            // we found a common initial character sequence
            return strs[0].substring(0, smallestIndexOfDiff);
        }
    }

    /**
     * <p>
     * Find the Levenshtein distance between two Strings.
     * </p>
     * <p/>
     * <p>
     * This is the number of changes needed to change one String into another,
     * where each change is a single character modification (deletion, insertion
     * or substitution).
     * </p>
     * <p/>
     * <p>
     * The previous implementation of the Levenshtein distance algorithm was
     * from <a
     * href="http://www.merriampark.com/ld.htm">http://www.merriampark.com
     * /ld.htm</a>
     * </p>
     * <p/>
     * <p>
     * Chas Emerick has written an implementation in Java, which avoids an
     * OutOfMemoryError which can occur when my Java implementation is used with
     * very large strings.<br>
     * This implementation of the Levenshtein distance algorithm is from <a
     * href="http://www.merriampark.com/ldjava.htm">http://www.merriampark.com/
     * ldjava.htm</a>
     * </p>
     * <p/>
     * <pre>
     * StringUtils.getLevenshteinDistance(null, *)             = IllegalArgumentException
     * StringUtils.getLevenshteinDistance(*, null)             = IllegalArgumentException
     * StringUtils.getLevenshteinDistance("","")               = 0
     * StringUtils.getLevenshteinDistance("","a")              = 1
     * StringUtils.getLevenshteinDistance("aaapppp", "")       = 7
     * StringUtils.getLevenshteinDistance("frog", "fog")       = 1
     * StringUtils.getLevenshteinDistance("fly", "ant")        = 3
     * StringUtils.getLevenshteinDistance("elephant", "hippo") = 7
     * StringUtils.getLevenshteinDistance("hippo", "elephant") = 7
     * StringUtils.getLevenshteinDistance("hippo", "zzzzzzzz") = 8
     * StringUtils.getLevenshteinDistance("hello", "hallo")    = 1
     * </pre>
     *
     * @param ss the first String, must not be null
     * @param tt the second String, must not be null
     * @return result distance
     * @throws IllegalArgumentException if either String input {@code null}
     * @since 3.0 Changed signature from getLevenshteinDistance(String, String)
     * to getLevenshteinDistance(CharSequence, CharSequence)
     */
    public static int getLevenshteinDistance(CharSequence ss, CharSequence tt) {
        CharSequence s = ss, t = tt;
        if (s == null || t == null) {
            throw new IllegalArgumentException("Strings must not be null");
        }

        /**
         * The difference between this impl. and the previous is that, rather
         * than creating and retaining a matrix of size s.length() + 1 by
         * t.length() + 1, we maintain two single-dimensional arrays of length
         * s.length() + 1. The first, d, is the 'current working' distance array
         * that maintains the newest distance cost counts as we iterate through
         * the characters of String s. Each time we increment the index of
         * String t we are comparing, d is copied to p, the second int[]. Doing
         * so allows us to retain the previous cost counts as required by the
         * algorithm (taking the minimum of the cost count to the left, up one,
         * and diagonally up and to the left of the current cost count being
         * calculated). (Note that the arrays aren't really copied anymore, just
         * switched...this is clearly much better than cloning an array or doing
         * a System.arraycopy() each time through the outer loop.)
         *
         * Effectively, the difference between the two implementations is this
         * one does not cause an out of memory condition when calculating the LD
         * over two very large strings.
         */

        int n = s.length();
        int m = t.length();

        if (n == 0) {
            return m;
        } else if (m == 0) {
            return n;
        }

        if (n > m) {
            // swap the input strings to consume less memory
            CharSequence tmp = s;
            s = t;
            t = tmp;
            n = m;
            m = t.length();
        }

        int[] p = new int[n + 1];
        int[] d = new int[n + 1];
        int[] pd;
        // indexes into strings s and t
        int i;
        int j;

        char tj;

        int cost;

        for (i = 0; i <= n; i++) {
            p[i] = i;
        }

        for (j = 1; j <= m; j++) {
            tj = t.charAt(j - 1);
            d[0] = j;

            for (i = 1; i <= n; i++) {
                cost = s.charAt(i - 1) == tj ? 0 : 1;
                // minimum of cell to the left+1, to the top+1, diagonally left
                // and up +cost
                d[i] = Math.min(Math.min(d[i - 1] + 1, p[i] + 1), p[i - 1] + cost);
            }

            // copy current distance counts to 'previous row' distance counts
            pd = p;
            p = d;
            d = pd;
        }

        // our last action in the above loop was to switch d and p, so p now
        // actually has the most recent cost counts
        return p[n];
    }

    /**
     * <p>
     * Find the Levenshtein distance between two Strings if it's less than or
     * equal to a given threshold.
     * </p>
     * <p/>
     * <p>
     * This is the number of changes needed to change one String into another,
     * where each change is a single character modification (deletion, insertion
     * or substitution).
     * </p>
     * <p/>
     * <p>
     * This implementation follows from Algorithms on Strings, Trees and
     * Sequences by Dan Gusfield and Chas Emerick's implementation of the
     * Levenshtein distance algorithm from <a
     * href="http://www.merriampark.com/ld.htm"
     * >http://www.merriampark.com/ld.htm</a>
     * </p>
     * <p/>
     * <pre>
     * StringUtils.getLevenshteinDistance(null, *, *)             = IllegalArgumentException
     * StringUtils.getLevenshteinDistance(*, null, *)             = IllegalArgumentException
     * StringUtils.getLevenshteinDistance(*, *, -1)               = IllegalArgumentException
     * StringUtils.getLevenshteinDistance("","", 0)               = 0
     * StringUtils.getLevenshteinDistance("aaapppp", "", 8)       = 7
     * StringUtils.getLevenshteinDistance("aaapppp", "", 7)       = 7
     * StringUtils.getLevenshteinDistance("aaapppp", "", 6))      = -1
     * StringUtils.getLevenshteinDistance("elephant", "hippo", 7) = 7
     * StringUtils.getLevenshteinDistance("elephant", "hippo", 6) = -1
     * StringUtils.getLevenshteinDistance("hippo", "elephant", 7) = 7
     * StringUtils.getLevenshteinDistance("hippo", "elephant", 6) = -1
     * </pre>
     *
     * @param ss        the first String, must not be null
     * @param tt        the second String, must not be null
     * @param threshold the target threshold, must not be negative
     * @return result distance, or {@code -1} if the distance would be greater
     * than the threshold
     * @throws IllegalArgumentException if either String input {@code null} or negative threshold
     */
    public static int getLevenshteinDistance(CharSequence ss, CharSequence tt, int threshold) {
        CharSequence s = ss, t = tt;
        if (s == null || t == null) {
            throw new IllegalArgumentException("Strings must not be null");
        }
        if (threshold < 0) {
            throw new IllegalArgumentException("Threshold must not be negative");
        }

        /**
         * This implementation only computes the distance if it's less than or
         * equal to the threshold value, returning -1 if it's greater. The
         * advantage is performance: unbounded distance is O(nm), but a bound of
         * k allows us to reduce it to O(km) time by only computing a diagonal
         * stripe of width 2k + 1 of the cost table. It is also possible to use
         * this to compute the unbounded Levenshtein distance by starting the
         * threshold at 1 and doubling each time until the distance is found;
         * this is O(dm), where d is the distance.
         *
         * One subtlety comes from needing to ignore entries on the border of
         * our stripe eg. p[] = |#|#|#|* d[] = *|#|#|#| We must ignore the entry
         * to the left of the leftmost member We must ignore the entry above the
         * rightmost member
         *
         * Another subtlety comes from our stripe running off the matrix if the
         * strings aren't of the same size. Since string s is always swapped to
         * be the shorter of the two, the stripe will always run off to the
         * upper right instead of the lower left of the matrix.
         *
         * As a concrete example, suppose s is of length 5, t is of length 7,
         * and our threshold is 1. In this case we're going to walk a stripe of
         * length 3. The matrix would look like so:
         *
         * 1 2 3 4 5 1 |#|#| | | | 2 |#|#|#| | | 3 | |#|#|#| | 4 | | |#|#|#| 5 |
         * | | |#|#| 6 | | | | |#| 7 | | | | | |
         *
         * Note how the stripe leads off the table as there is no possible way
         * to turn a string of length 5 into one of length 7 in edit distance of
         * 1.
         *
         * Additionally, this implementation decreases memory usage by using two
         * single-dimensional arrays and swapping them back and forth instead of
         * allocating an entire n by m matrix. This requires a few minor
         * changes, such as immediately returning when it's detected that the
         * stripe has run off the matrix and initially filling the arrays with
         * large values so that entries we don't compute are ignored.
         *
         * See Algorithms on Strings, Trees and Sequences by Dan Gusfield for
         * some discussion.
         */

        int n = s.length();
        int m = t.length();

        // if one string is empty, the edit distance is necessarily the length
        // of the other
        if (n == 0) {
            return m <= threshold ? m : -1;
        } else if (m == 0) {
            return n <= threshold ? n : -1;
        }

        if (n > m) {
            // swap the two strings to consume less memory
            CharSequence tmp = s;
            s = t;
            t = tmp;
            n = m;
            m = t.length();
        }

        int[] p = new int[n + 1];
        int[] d = new int[n + 1];
        int[] pd;

        // fill in starting table values
        int boundary = Math.min(n, threshold) + 1;
        for (int i = 0; i < boundary; i++) {
            p[i] = i;
        }
        // these fills ensure that the value above the rightmost entry of our
        // stripe will be ignored in following loop iterations
        Arrays.fill(p, boundary, p.length, Integer.MAX_VALUE);
        Arrays.fill(d, Integer.MAX_VALUE);

        // iterates through t
        for (int j = 1; j <= m; j++) {
            char tj = t.charAt(j - 1);
            d[0] = j;

            // compute stripe indices, constrain to array size
            int min = Math.max(1, j - threshold);
            int max = Math.min(n, j + threshold);

            // the stripe may lead off of the table if s and t are of different
            // sizes
            if (min > max) {
                return -1;
            }

            // ignore entry left of leftmost
            if (min > 1) {
                d[min - 1] = Integer.MAX_VALUE;
            }

            // iterates through [min, max] in s
            for (int i = min; i <= max; i++) {
                if (s.charAt(i - 1) == tj) {
                    // diagonally left and up
                    d[i] = p[i - 1];
                } else {
                    // 1 + minimum of cell to the left, to the top, diagonally
                    // left and up
                    d[i] = 1 + Math.min(Math.min(d[i - 1], p[i]), p[i - 1]);
                }
            }

            // copy current distance counts to 'previous row' distance counts
            pd = p;
            p = d;
            d = pd;
        }

        // if p[n] is greater than the threshold, there's no guarantee on it
        // being the correct
        // distance
        if (p[n] <= threshold) {
            return p[n];
        } else {
            return -1;
        }
    }

    /**
     * <p>
     * Check if a CharSequence starts with a specified prefix.
     * </p>
     * <p/>
     * <p>
     * {@code null}s are handled without exceptions. Two {@code null} references
     * are considered to be equal. The comparison is case sensitive.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.startsWith(null, null)      = true
     * StringUtils.startsWith(null, "abc")     = false
     * StringUtils.startsWith("abcdef", null)  = false
     * StringUtils.startsWith("abcdef", "abc") = true
     * StringUtils.startsWith("ABCDEF", "abc") = false
     * </pre>
     *
     * @param str    the CharSequence to check, may be null
     * @param prefix the prefix to find, may be null
     * @return {@code true} if the CharSequence starts with the prefix, case
     * sensitive, or both {@code null}
     * @see java.lang.String#startsWith(String)
     * @since 3.0 Changed signature from startsWith(String, String) to
     * startsWith(CharSequence, CharSequence)
     */
    public static boolean startsWith(CharSequence str, CharSequence prefix) {
        return startsWith(str, prefix, false);
    }

    /**
     * <p>
     * Case insensitive check if a CharSequence starts with a specified prefix.
     * </p>
     * <p/>
     * <p>
     * {@code null}s are handled without exceptions. Two {@code null} references
     * are considered to be equal. The comparison is case insensitive.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.startsWithIgnoreCase(null, null)      = true
     * StringUtils.startsWithIgnoreCase(null, "abc")     = false
     * StringUtils.startsWithIgnoreCase("abcdef", null)  = false
     * StringUtils.startsWithIgnoreCase("abcdef", "abc") = true
     * StringUtils.startsWithIgnoreCase("ABCDEF", "abc") = true
     * </pre>
     *
     * @param str    the CharSequence to check, may be null
     * @param prefix the prefix to find, may be null
     * @return {@code true} if the CharSequence starts with the prefix, case
     * insensitive, or both {@code null}
     * @see java.lang.String#startsWith(String)
     * @since 3.0 Changed signature from startsWithIgnoreCase(String, String) to
     * startsWithIgnoreCase(CharSequence, CharSequence)
     */
    public static boolean startsWithIgnoreCase(CharSequence str, CharSequence prefix) {
        return startsWith(str, prefix, true);
    }

    /**
     * <p>
     * Check if a CharSequence starts with a specified prefix (optionally case
     * insensitive).
     * </p>
     *
     * @param str        the CharSequence to check, may be null
     * @param prefix     the prefix to find, may be null
     * @param ignoreCase indicates whether the compare should ignore case (case
     *                   insensitive) or not.
     * @return {@code true} if the CharSequence starts with the prefix or both
     * {@code null}
     * @see java.lang.String#startsWith(String)
     */
    private static boolean startsWith(CharSequence str, CharSequence prefix, boolean ignoreCase) {
        if (str == null || prefix == null) {
            return str == null && prefix == null;
        }
        if (prefix.length() > str.length()) {
            return false;
        }
        return CharSequenceUtils.regionMatches(str, ignoreCase, 0, prefix, 0, prefix.length());
    }

    /**
     * <p>
     * Check if a CharSequence starts with any of an array of specified strings.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.startsWithAny(null, null)      = false
     * StringUtils.startsWithAny(null, new String[] {"abc"})  = false
     * StringUtils.startsWithAny("abcxyz", null)     = false
     * StringUtils.startsWithAny("abcxyz", new String[] {""}) = false
     * StringUtils.startsWithAny("abcxyz", new String[] {"abc"}) = true
     * StringUtils.startsWithAny("abcxyz", new String[] {null, "xyz", "abc"}) = true
     * </pre>
     *
     * @param string        the CharSequence to check, may be null
     * @param searchStrings the CharSequences to find, may be null or empty
     * @return {@code true} if the CharSequence starts with any of the the
     * prefixes, case insensitive, or both {@code null}
     * @since 3.0 Changed signature from startsWithAny(String, String[]) to
     * startsWithAny(CharSequence, CharSequence...)
     */
    public static boolean startsWithAny(CharSequence string, CharSequence... searchStrings) {
        if (isEmpty(string) || searchStrings == null) {
            return false;
        }
        for (CharSequence searchString : searchStrings) {
            if (StringUtils.startsWith(string, searchString)) {
                return true;
            }
        }
        return false;
    }

    /**
     * <p>
     * Check if a CharSequence ends with a specified suffix.
     * </p>
     * <p/>
     * <p>
     * {@code null}s are handled without exceptions. Two {@code null} references
     * are considered to be equal. The comparison is case sensitive.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.endsWith(null, null)      = true
     * StringUtils.endsWith(null, "def")     = false
     * StringUtils.endsWith("abcdef", null)  = false
     * StringUtils.endsWith("abcdef", "def") = true
     * StringUtils.endsWith("ABCDEF", "def") = false
     * StringUtils.endsWith("ABCDEF", "cde") = false
     * </pre>
     *
     * @param str    the CharSequence to check, may be null
     * @param suffix the suffix to find, may be null
     * @return {@code true} if the CharSequence ends with the suffix, case
     * sensitive, or both {@code null}
     * @see java.lang.String#endsWith(String)
     * @since 3.0 Changed signature from endsWith(String, String) to
     * endsWith(CharSequence, CharSequence)
     */
    public static boolean endsWith(CharSequence str, CharSequence suffix) {
        return endsWith(str, suffix, false);
    }

    /**
     * <p>
     * Case insensitive check if a CharSequence ends with a specified suffix.
     * </p>
     * <p/>
     * <p>
     * {@code null}s are handled without exceptions. Two {@code null} references
     * are considered to be equal. The comparison is case insensitive.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.endsWithIgnoreCase(null, null)      = true
     * StringUtils.endsWithIgnoreCase(null, "def")     = false
     * StringUtils.endsWithIgnoreCase("abcdef", null)  = false
     * StringUtils.endsWithIgnoreCase("abcdef", "def") = true
     * StringUtils.endsWithIgnoreCase("ABCDEF", "def") = true
     * StringUtils.endsWithIgnoreCase("ABCDEF", "cde") = false
     * </pre>
     *
     * @param str    the CharSequence to check, may be null
     * @param suffix the suffix to find, may be null
     * @return {@code true} if the CharSequence ends with the suffix, case
     * insensitive, or both {@code null}
     * @see java.lang.String#endsWith(String)
     * @since 3.0 Changed signature from endsWithIgnoreCase(String, String) to
     * endsWithIgnoreCase(CharSequence, CharSequence)
     */
    public static boolean endsWithIgnoreCase(CharSequence str, CharSequence suffix) {
        return endsWith(str, suffix, true);
    }

    /**
     * <p>
     * Check if a CharSequence ends with a specified suffix (optionally case
     * insensitive).
     * </p>
     *
     * @param str        the CharSequence to check, may be null
     * @param suffix     the suffix to find, may be null
     * @param ignoreCase indicates whether the compare should ignore case (case
     *                   insensitive) or not.
     * @return {@code true} if the CharSequence starts with the prefix or both
     * {@code null}
     * @see java.lang.String#endsWith(String)
     */
    private static boolean endsWith(CharSequence str, CharSequence suffix, boolean ignoreCase) {
        if (str == null || suffix == null) {
            return str == null && suffix == null;
        }
        if (suffix.length() > str.length()) {
            return false;
        }
        int strOffset = str.length() - suffix.length();
        return CharSequenceUtils.regionMatches(str, ignoreCase, strOffset, suffix, 0, suffix.length());
    }

    /**
     * <p>
     * Similar to <a
     * href="http://www.w3.org/TR/xpath/#function-normalize-space">
     * http://www.w3.org/TR/xpath/#function-normalize -space</a>
     * </p>
     * <p>
     * The function returns the argument string with whitespace normalized by
     * using <code>{@link #trim(String)}</code> to remove leading and trailing
     * whitespace and then replacing sequences of whitespace characters by a
     * single space.
     * </p>
     * In XML Whitespace characters are the same as those allowed by the <a
     * href="http://www.w3.org/TR/REC-xml/#NT-S">S</a> production, which is S
     * ::= (#x20 | #x9 | #xD | #xA)+
     * <p>
     * Java's regexp pattern \s defines whitespace as [ \t\n\x0B\f\r]
     * <p>
     * For reference:
     * <ul>
     * <li>\x0B = vertical tab</li>
     * <li>\f = #xC = form feed</li>
     * <li>#x20 = space</li>
     * <li>#x9 = \t</li>
     * <li>#xA = \n</li>
     * <li>#xD = \r</li>
     * </ul>
     * </p>
     * <p>
     * The difference is that Java's whitespace includes vertical tab and form
     * feed, which this functional will also normalize. Additionally
     * <code>{@link #trim(String)}</code> removes control characters (char &lt;=
     * 32) from both ends of this String.
     * </p>
     *
     * @param str the source String to normalize whitespaces from, may be null
     * @return the modified string with whitespace normalized, {@code null} if
     * null String input
     * @see Pattern
     * @see #trim(String)
     * @see <a
     * href="http://www.w3.org/TR/xpath/#function-normalize-space">http://www.w3.org/TR/xpath/#function-normalize-space</a>
     * @since 3.0
     */
    public static String normalizeSpace(String str) {
        if (str == null) {
            return null;
        }
        return WHITESPACE_BLOCK.matcher(trim(str)).replaceAll(" ");
    }

    /**
     * <p>
     * Check if a CharSequence ends with any of an array of specified strings.
     * </p>
     * <p/>
     * <pre>
     * StringUtils.endsWithAny(null, null)      = false
     * StringUtils.endsWithAny(null, new String[] {"abc"})  = false
     * StringUtils.endsWithAny("abcxyz", null)     = false
     * StringUtils.endsWithAny("abcxyz", new String[] {""}) = true
     * StringUtils.endsWithAny("abcxyz", new String[] {"xyz"}) = true
     * StringUtils.endsWithAny("abcxyz", new String[] {null, "xyz", "abc"}) = true
     * </pre>
     *
     * @param string        the CharSequence to check, may be null
     * @param searchStrings the CharSequences to find, may be null or empty
     * @return {@code true} if the CharSequence ends with any of the the
     * prefixes, case insensitive, or both {@code null}
     * @since 3.0
     */
    public static boolean endsWithAny(CharSequence string, CharSequence... searchStrings) {
        if (isEmpty(string) || searchStrings == null) {
            return false;
        }
        for (CharSequence searchString : searchStrings) {
            if (StringUtils.endsWith(string, searchString)) {
                return true;
            }
        }
        return false;
    }

    /**
     * Converts a <code>byte[]</code> to a String using the specified character
     * encoding.
     *
     * @param bytes       the byte array to read from
     * @param charsetName the encoding to use, if null then use the platform default
     * @return a new String
     * @throws UnsupportedEncodingException If the named charset is not supported
     * @throws NullPointerException         if the input is null
     * @since 3.1
     */
    public static String toString(byte[] bytes, String charsetName) throws UnsupportedEncodingException {
        return charsetName == null ? new String(bytes) : new String(bytes, charsetName);
    }
}