Java tutorial
/* * Copyright (c) 2012-2013, Batu Alp Ceylan * * This copyrighted material is made available to anyone wishing to use, modify, * copy, or redistribute it subject to the terms and conditions of the GNU * Lesser General Public License, as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License * for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this distribution; if not, write to: * Free Software Foundation, Inc. * 51 Franklin Street, Fifth Floor * Boston, MA 02110-1301 USA */ package org.batoo.common.util; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.Enumeration; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.Locale; import java.util.Properties; import java.util.Set; import java.util.StringTokenizer; import java.util.TreeSet; /** * Miscellaneous {@link String} utility methods. * * <p> * Mainly for internal use within the framework; consider <a href="http://jakarta.apache.org/commons/lang/">Jakarta's Commons Lang</a> for a * more comprehensive suite of String utilities. * * <p> * This class delivers some simple functionality that should really be provided by the core Java <code>String</code> and * {@link StringBuilder} classes, such as the ability to {@link #replace} all occurrences of a given substring in a target string. It also * provides easy-to-use methods to convert between delimited strings, such as CSV strings, and collections and arrays. * * @author hceylan * @see org.apache.commons.lang.StringUtils */ public abstract class StringUtils { private static final String FOLDER_SEPARATOR = "/"; private static final String WINDOWS_FOLDER_SEPARATOR = "\\"; private static final String TOP_PATH = ".."; private static final String CURRENT_PATH = "."; private static final char EXTENSION_SEPARATOR = '.'; /** * Append the given String to the given String array, returning a new array consisting of the input array contents plus the given * String. * * @param array * the array to append to (can be <code>null</code>) * @param str * the String to append * @return the new array (never <code>null</code>) */ public static String[] addStringToArray(String[] array, String str) { if (ObjectUtils.isEmpty(array)) { return new String[] { str }; } final String[] newArr = new String[array.length + 1]; System.arraycopy(array, 0, newArr, 0, array.length); newArr[array.length] = str; return newArr; } /** * Apply the given relative path to the given path, assuming standard Java folder separation (i.e. "/" separators). * * @param path * the path to start from (usually a full file path) * @param relativePath * the relative path to apply (relative to the full file path above) * @return the full file path that results from applying the relative path */ public static String applyRelativePath(String path, String relativePath) { final int separatorIndex = path.lastIndexOf(StringUtils.FOLDER_SEPARATOR); if (separatorIndex != -1) { String newPath = path.substring(0, separatorIndex); if (!relativePath.startsWith(StringUtils.FOLDER_SEPARATOR)) { newPath += StringUtils.FOLDER_SEPARATOR; } return newPath + relativePath; } else { return relativePath; } } /** * Convenience method to return a String array as a CSV String. E.g. useful for <code>toString()</code> implementations. * * @param arr * the array to display * @return the delimited String */ public static String arrayToCommaDelimitedString(Object[] arr) { return StringUtils.arrayToDelimitedString(arr, ","); } /** * Convenience method to return a String array as a delimited (e.g. CSV) String. E.g. useful for <code>toString()</code> * implementations. * * @param arr * the array to display * @param delim * the delimiter to use (probably a ",") * @return the delimited String */ public static String arrayToDelimitedString(Object[] arr, String delim) { if (ObjectUtils.isEmpty(arr)) { return ""; } if (arr.length == 1) { return ObjectUtils.nullSafeToString(arr[0]); } final StringBuilder sb = new StringBuilder(); for (int i = 0; i < arr.length; i++) { if (i > 0) { sb.append(delim); } sb.append(arr[i]); } return sb.toString(); } /** * Capitalize a <code>String</code>, changing the first letter to upper case as per {@link Character#toUpperCase(char)}. No other * letters are changed. * * @param str * the String to capitalize, may be <code>null</code> * @return the capitalized String, <code>null</code> if null */ public static String capitalize(String str) { return StringUtils.changeFirstCharacterCase(str, true); } private static String changeFirstCharacterCase(String str, boolean capitalize) { if ((str == null) || (str.length() == 0)) { return str; } final StringBuilder sb = new StringBuilder(str.length()); if (capitalize) { sb.append(Character.toUpperCase(str.charAt(0))); } else { sb.append(Character.toLowerCase(str.charAt(0))); } sb.append(str.substring(1)); return sb.toString(); } /** * Normalize the path by suppressing sequences like "path/.." and inner simple dots. * <p> * The result is convenient for path comparison. For other uses, notice that Windows separators ("\") are replaced by simple slashes. * * @param path * the original path * @return the normalized path */ public static String cleanPath(String path) { if (path == null) { return null; } String pathToUse = StringUtils.replace(path, StringUtils.WINDOWS_FOLDER_SEPARATOR, StringUtils.FOLDER_SEPARATOR); // Strip prefix from path to analyze, to not treat it as part of the // first path element. This is necessary to correctly parse paths like // "file:core/../core/io/Resource.class", where the ".." should just // strip the first "core" directory while keeping the "file:" prefix. final int prefixIndex = pathToUse.indexOf(":"); String prefix = ""; if (prefixIndex != -1) { prefix = pathToUse.substring(0, prefixIndex + 1); pathToUse = pathToUse.substring(prefixIndex + 1); } if (pathToUse.startsWith(StringUtils.FOLDER_SEPARATOR)) { prefix = prefix + StringUtils.FOLDER_SEPARATOR; pathToUse = pathToUse.substring(1); } final String[] pathArray = StringUtils.delimitedListToStringArray(pathToUse, StringUtils.FOLDER_SEPARATOR); final List<String> pathElements = new LinkedList<String>(); int tops = 0; for (int i = pathArray.length - 1; i >= 0; i--) { final String element = pathArray[i]; if (StringUtils.CURRENT_PATH.equals(element)) { // Points to current directory - drop it. } else if (StringUtils.TOP_PATH.equals(element)) { // Registering top path found. tops++; } else { if (tops > 0) { // Merging path element with element corresponding to top path. tops--; } else { // Normal path element found. pathElements.add(0, element); } } } // Remaining top paths need to be retained. for (int i = 0; i < tops; i++) { pathElements.add(0, StringUtils.TOP_PATH); } return prefix + StringUtils.collectionToDelimitedString(pathElements, StringUtils.FOLDER_SEPARATOR); } /** * Convenience method to return a Collection as a CSV String. E.g. useful for <code>toString()</code> implementations. * * @param coll * the Collection to display * @return the delimited String */ public static String collectionToCommaDelimitedString(Collection<?> coll) { return StringUtils.collectionToDelimitedString(coll, ","); } /** * Convenience method to return a Collection as a delimited (e.g. CSV) String. E.g. useful for <code>toString()</code> implementations. * * @param coll * the Collection to display * @param delim * the delimiter to use (probably a ",") * @return the delimited String */ public static String collectionToDelimitedString(Collection<?> coll, String delim) { return StringUtils.collectionToDelimitedString(coll, delim, "", ""); } /** * Convenience method to return a Collection as a delimited (e.g. CSV) String. E.g. useful for <code>toString()</code> implementations. * * @param coll * the Collection to display * @param delim * the delimiter to use (probably a ",") * @param prefix * the String to start each element with * @param suffix * the String to end each element with * @return the delimited String */ public static String collectionToDelimitedString(Collection<?> coll, String delim, String prefix, String suffix) { if (CollectionUtils.isEmpty(coll)) { return ""; } final StringBuilder sb = new StringBuilder(); final Iterator<?> it = coll.iterator(); while (it.hasNext()) { sb.append(prefix).append(it.next()).append(suffix); if (it.hasNext()) { sb.append(delim); } } return sb.toString(); } /** * Convenience method to convert a CSV string list to a set. Note that this will suppress duplicates. * * @param str * the input String * @return a Set of String entries in the list */ public static Set<String> commaDelimitedListToSet(String str) { final Set<String> set = new TreeSet<String>(); final String[] tokens = StringUtils.commaDelimitedListToStringArray(str); for (final String token : tokens) { set.add(token); } return set; } /** * Convert a CSV list into an array of Strings. * * @param str * the input String * @return an array of Strings, or the empty array in case of empty input */ public static String[] commaDelimitedListToStringArray(String str) { return StringUtils.delimitedListToStringArray(str, ","); } /** * Concatenate the given String arrays into one, with overlapping array elements included twice. * <p> * The order of elements in the original arrays is preserved. * * @param array1 * the first array (can be <code>null</code>) * @param array2 * the second array (can be <code>null</code>) * @return the new array (<code>null</code> if both given arrays were <code>null</code>) */ public static String[] concatenateStringArrays(String[] array1, String[] array2) { if (ObjectUtils.isEmpty(array1)) { return array2; } if (ObjectUtils.isEmpty(array2)) { return array1; } final String[] newArr = new String[array1.length + array2.length]; System.arraycopy(array1, 0, newArr, 0, array1.length); System.arraycopy(array2, 0, newArr, array1.length, array2.length); return newArr; } /** * Check whether the given CharSequence contains any whitespace characters. * * @param str * the CharSequence to check (may be <code>null</code>) * @return <code>true</code> if the CharSequence is not empty and contains at least 1 whitespace character * @see java.lang.Character#isWhitespace */ public static boolean containsWhitespace(CharSequence str) { if (!StringUtils.hasLength(str)) { return false; } final int strLen = str.length(); for (int i = 0; i < strLen; i++) { if (Character.isWhitespace(str.charAt(i))) { return true; } } return false; } /** * Check whether the given String contains any whitespace characters. * * @param str * the String to check (may be <code>null</code>) * @return <code>true</code> if the String is not empty and contains at least 1 whitespace character * @see #containsWhitespace(CharSequence) */ public static boolean containsWhitespace(String str) { return StringUtils.containsWhitespace((CharSequence) str); } /** * Count the occurrences of the substring in string s. * * @param str * string to search in. Return 0 if this is null. * @param sub * string to search for. Return 0 if this is null. * @return the count */ public static int countOccurrencesOf(String str, String sub) { if ((str == null) || (sub == null) || (str.length() == 0) || (sub.length() == 0)) { return 0; } int count = 0; int pos = 0; int idx; while ((idx = str.indexOf(sub, pos)) != -1) { ++count; pos = idx + sub.length(); } return count; } /** * Delete all occurrences of the given substring. * * @param inString * the original String * @param pattern * the pattern to delete all occurrences of * @return the resulting String */ public static String delete(String inString, String pattern) { return StringUtils.replace(inString, pattern, ""); } /** * Delete any character in a given String. * * @param inString * the original String * @param charsToDelete * a set of characters to delete. E.g. "az\n" will delete 'a's, 'z's and new lines. * @return the resulting String */ public static String deleteAny(String inString, String charsToDelete) { if (!StringUtils.hasLength(inString) || !StringUtils.hasLength(charsToDelete)) { return inString; } final StringBuilder sb = new StringBuilder(); for (int i = 0; i < inString.length(); i++) { final char c = inString.charAt(i); if (charsToDelete.indexOf(c) == -1) { sb.append(c); } } return sb.toString(); } /** * Take a String which is a delimited list and convert it to a String array. * <p> * A single delimiter can consists of more than one character: It will still be considered as single delimiter string, rather than as * bunch of potential delimiter characters - in contrast to <code>tokenizeToStringArray</code>. * * @param str * the input String * @param delimiter * the delimiter between elements (this is a single delimiter, rather than a bunch individual delimiter characters) * @return an array of the tokens in the list * @see #tokenizeToStringArray */ public static String[] delimitedListToStringArray(String str, String delimiter) { return StringUtils.delimitedListToStringArray(str, delimiter, null); } /** * Take a String which is a delimited list and convert it to a String array. * <p> * A single delimiter can consists of more than one character: It will still be considered as single delimiter string, rather than as * bunch of potential delimiter characters - in contrast to <code>tokenizeToStringArray</code>. * * @param str * the input String * @param delimiter * the delimiter between elements (this is a single delimiter, rather than a bunch individual delimiter characters) * @param charsToDelete * a set of characters to delete. Useful for deleting unwanted line breaks: e.g. "\r\n\f" will delete all new lines and line * feeds in a String. * @return an array of the tokens in the list * @see #tokenizeToStringArray */ public static String[] delimitedListToStringArray(String str, String delimiter, String charsToDelete) { if (str == null) { return new String[0]; } if (delimiter == null) { return new String[] { str }; } final List<String> result = new ArrayList<String>(); if ("".equals(delimiter)) { for (int i = 0; i < str.length(); i++) { result.add(StringUtils.deleteAny(str.substring(i, i + 1), charsToDelete)); } } else { int pos = 0; int delPos; while ((delPos = str.indexOf(delimiter, pos)) != -1) { result.add(StringUtils.deleteAny(str.substring(pos, delPos), charsToDelete)); pos = delPos + delimiter.length(); } if ((str.length() > 0) && (pos <= str.length())) { // Add rest of String, but not in case of empty input. result.add(StringUtils.deleteAny(str.substring(pos), charsToDelete)); } } return StringUtils.toStringArray(result); } /** * Test if the given String ends with the specified suffix, ignoring upper/lower case. * * @param str * the String to check * @param suffix * the suffix to look for * @return <code>true</code> if given String ends with the specified suffix, <code>false</code> otherwise * @see java.lang.String#endsWith */ public static boolean endsWithIgnoreCase(String str, String suffix) { if ((str == null) || (suffix == null)) { return false; } if (str.endsWith(suffix)) { return true; } if (str.length() < suffix.length()) { return false; } final String lcStr = str.substring(str.length() - suffix.length()).toLowerCase(); final String lcSuffix = suffix.toLowerCase(); return lcStr.equals(lcSuffix); } // --------------------------------------------------------------------- // Convenience methods for working with formatted Strings // --------------------------------------------------------------------- /** * Extract the filename from the given path, e.g. "mypath/myfile.txt" -> "myfile.txt". * * @param path * the file path (may be <code>null</code>) * @return the extracted filename, or <code>null</code> if none */ public static String getFilename(String path) { if (path == null) { return null; } final int separatorIndex = path.lastIndexOf(StringUtils.FOLDER_SEPARATOR); return (separatorIndex != -1 ? path.substring(separatorIndex + 1) : path); } /** * Extract the filename extension from the given path, e.g. "mypath/myfile.txt" -> "txt". * * @param path * the file path (may be <code>null</code>) * @return the extracted filename extension, or <code>null</code> if none */ public static String getFilenameExtension(String path) { if (path == null) { return null; } final int extIndex = path.lastIndexOf(StringUtils.EXTENSION_SEPARATOR); if (extIndex == -1) { return null; } final int folderIndex = path.lastIndexOf(StringUtils.FOLDER_SEPARATOR); if (folderIndex > extIndex) { return null; } return path.substring(extIndex + 1); } /** * Check that the given CharSequence is neither <code>null</code> nor of length 0. Note: Will return <code>true</code> for a * CharSequence that purely consists of whitespace. * <p> * * <pre> * StringUtils.hasLength(null) = false * StringUtils.hasLength("") = false * StringUtils.hasLength(" ") = true * StringUtils.hasLength("Hello") = true * </pre> * * @param str * the CharSequence to check (may be <code>null</code>) * @return <code>true</code> if the CharSequence is not null and has length * @see #hasText(String) */ public static boolean hasLength(CharSequence str) { return ((str != null) && (str.length() > 0)); } /** * Check that the given String is neither <code>null</code> nor of length 0. Note: Will return <code>true</code> for a String that * purely consists of whitespace. * * @param str * the String to check (may be <code>null</code>) * @return <code>true</code> if the String is not null and has length * @see #hasLength(CharSequence) */ public static boolean hasLength(String str) { return StringUtils.hasLength((CharSequence) str); } /** * Check whether the given CharSequence has actual text. More specifically, returns <code>true</code> if the string not * <code>null</code>, its length is greater than 0, and it contains at least one non-whitespace character. * <p> * * <pre> * StringUtils.hasText(null) = false * StringUtils.hasText("") = false * StringUtils.hasText(" ") = false * StringUtils.hasText("12345") = true * StringUtils.hasText(" 12345 ") = true * </pre> * * @param str * the CharSequence to check (may be <code>null</code>) * @return <code>true</code> if the CharSequence is not <code>null</code>, its length is greater than 0, and it does not contain * whitespace only * @see java.lang.Character#isWhitespace */ public static boolean hasText(CharSequence str) { if (!StringUtils.hasLength(str)) { return false; } final int strLen = str.length(); for (int i = 0; i < strLen; i++) { if (!Character.isWhitespace(str.charAt(i))) { return true; } } return false; } /** * Check whether the given String has actual text. More specifically, returns <code>true</code> if the string not <code>null</code>, its * length is greater than 0, and it contains at least one non-whitespace character. * * @param str * the String to check (may be <code>null</code>) * @return <code>true</code> if the String is not <code>null</code>, its length is greater than 0, and it does not contain whitespace * only * @see #hasText(CharSequence) */ public static boolean hasText(String str) { return StringUtils.hasText((CharSequence) str); } /** * <p> * Checks if a String is whitespace, empty ("") or null. * </p> * * <pre> * StringUtils.isBlank(null) = true * StringUtils.isBlank("") = true * StringUtils.isBlank(" ") = true * StringUtils.isBlank("bob") = false * StringUtils.isBlank(" bob ") = false * </pre> * * @param str * the String to check, may be null * @return <code>true</code> if the String is null, empty or whitespace * @since 2.0 */ public static boolean isBlank(String str) { int strLen; if ((str == null) || ((strLen = str.length()) == 0)) { return true; } for (int i = 0; i < strLen; i++) { if ((Character.isWhitespace(str.charAt(i)) == false)) { return false; } } return true; } /** * <p> * Checks if a String is not empty (""), not null and not whitespace only. * </p> * * <pre> * StringUtils.isNotBlank(null) = false * StringUtils.isNotBlank("") = false * StringUtils.isNotBlank(" ") = false * StringUtils.isNotBlank("bob") = true * StringUtils.isNotBlank(" bob ") = true * </pre> * * @param str * the String to check, may be null * @return <code>true</code> if the String is not empty and not null and not whitespace * @since 2.0 */ public static boolean isNotBlank(String str) { return !StringUtils.isBlank(str); } /** * Merge the given String arrays into one, with overlapping array elements only included once. * <p> * The order of elements in the original arrays is preserved (with the exception of overlapping elements, which are only included on * their first occurrence). * * @param array1 * the first array (can be <code>null</code>) * @param array2 * the second array (can be <code>null</code>) * @return the new array (<code>null</code> if both given arrays were <code>null</code>) */ public static String[] mergeStringArrays(String[] array1, String[] array2) { if (ObjectUtils.isEmpty(array1)) { return array2; } if (ObjectUtils.isEmpty(array2)) { return array1; } final List<String> result = new ArrayList<String>(); result.addAll(Arrays.asList(array1)); for (final String str : array2) { if (!result.contains(str)) { result.add(str); } } return StringUtils.toStringArray(result); } /** * Parse the given <code>localeString</code> value into a {@link Locale}. * <p> * This is the inverse operation of {@link Locale#toString Locale's toString}. * * @param localeString * the locale string, following <code>Locale's</code> <code>toString()</code> format ("en", "en_UK", etc); also accepts * spaces as separators, as an alternative to underscores * @return a corresponding <code>Locale</code> instance */ public static Locale parseLocaleString(String localeString) { final String[] parts = StringUtils.tokenizeToStringArray(localeString, "_ ", false, false); final String language = (parts.length > 0 ? parts[0] : ""); final String country = (parts.length > 1 ? parts[1] : ""); StringUtils.validateLocalePart(language); StringUtils.validateLocalePart(country); String variant = ""; if (parts.length >= 2) { // There is definitely a variant, and it is everything after the country // code sans the separator between the country code and the variant. final int endIndexOfCountryCode = localeString.lastIndexOf(country) + country.length(); // Strip off any leading '_' and whitespace, what's left is the variant. variant = StringUtils.trimLeadingWhitespace(localeString.substring(endIndexOfCountryCode)); if (variant.startsWith("_")) { variant = StringUtils.trimLeadingCharacter(variant, '_'); } } return (language.length() > 0 ? new Locale(language, country, variant) : null); } /** * Compare two paths after normalization of them. * * @param path1 * first path for comparison * @param path2 * second path for comparison * @return whether the two paths are equivalent after normalization */ public static boolean pathEquals(String path1, String path2) { return StringUtils.cleanPath(path1).equals(StringUtils.cleanPath(path2)); } /** * Quote the given String with single quotes. * * @param str * the input String (e.g. "myString") * @return the quoted String (e.g. "'myString'"), or <code>null<code> if the input was <code>null</code> */ public static String quote(String str) { return (str != null ? "'" + str + "'" : null); } /** * Turn the given Object into a String with single quotes if it is a String; keeping the Object as-is else. * * @param obj * the input Object (e.g. "myString") * @return the quoted String (e.g. "'myString'"), or the input object as-is if not a String */ public static Object quoteIfString(Object obj) { return (obj instanceof String ? StringUtils.quote((String) obj) : obj); } /** * Remove duplicate Strings from the given array. Also sorts the array, as it uses a TreeSet. * * @param array * the String array * @return an array without duplicates, in natural sort order */ public static String[] removeDuplicateStrings(String[] array) { if (ObjectUtils.isEmpty(array)) { return array; } final Set<String> set = new TreeSet<String>(); for (final String element : array) { set.add(element); } return StringUtils.toStringArray(set); } /** * Replace all occurences of a substring within a string with another string. * * @param inString * String to examine * @param oldPattern * String to replace * @param newPattern * String to insert * @return a String with the replacements */ public static String replace(String inString, String oldPattern, String newPattern) { if (!StringUtils.hasLength(inString) || !StringUtils.hasLength(oldPattern) || (newPattern == null)) { return inString; } final StringBuilder sb = new StringBuilder(); int pos = 0; // our position in the old string int index = inString.indexOf(oldPattern); // the index of an occurrence we've found, or -1 final int patLen = oldPattern.length(); while (index >= 0) { sb.append(inString.substring(pos, index)); sb.append(newPattern); pos = index + patLen; index = inString.indexOf(oldPattern, pos); } sb.append(inString.substring(pos)); // remember to append any characters to the right of a match return sb.toString(); } /** * Turn given source String array into sorted array. * * @param array * the source array * @return the sorted array (never <code>null</code>) */ public static String[] sortStringArray(String[] array) { if (ObjectUtils.isEmpty(array)) { return new String[0]; } Arrays.sort(array); return array; } // --------------------------------------------------------------------- // Convenience methods for working with String arrays // --------------------------------------------------------------------- /** * Split a String at the first occurrence of the delimiter. Does not include the delimiter in the result. * * @param toSplit * the string to split * @param delimiter * to split the string up with * @return a two element array with index 0 being before the delimiter, and index 1 being after the delimiter (neither element includes * the delimiter); or <code>null</code> if the delimiter wasn't found in the given input String */ public static String[] split(String toSplit, String delimiter) { if (!StringUtils.hasLength(toSplit) || !StringUtils.hasLength(delimiter)) { return null; } final int offset = toSplit.indexOf(delimiter); if (offset < 0) { return null; } final String beforeDelimiter = toSplit.substring(0, offset); final String afterDelimiter = toSplit.substring(offset + delimiter.length()); return new String[] { beforeDelimiter, afterDelimiter }; } /** * Take an array Strings and split each element based on the given delimiter. A <code>Properties</code> instance is then generated, with * the left of the delimiter providing the key, and the right of the delimiter providing the value. * <p> * Will trim both the key and value before adding them to the <code>Properties</code> instance. * * @param array * the array to process * @param delimiter * to split each element using (typically the equals symbol) * @return a <code>Properties</code> instance representing the array contents, or <code>null</code> if the array to process was null or * empty */ public static Properties splitArrayElementsIntoProperties(String[] array, String delimiter) { return StringUtils.splitArrayElementsIntoProperties(array, delimiter, null); } /** * Take an array Strings and split each element based on the given delimiter. A <code>Properties</code> instance is then generated, with * the left of the delimiter providing the key, and the right of the delimiter providing the value. * <p> * Will trim both the key and value before adding them to the <code>Properties</code> instance. * * @param array * the array to process * @param delimiter * to split each element using (typically the equals symbol) * @param charsToDelete * one or more characters to remove from each element prior to attempting the split operation (typically the quotation mark * symbol), or <code>null</code> if no removal should occur * @return a <code>Properties</code> instance representing the array contents, or <code>null</code> if the array to process was * <code>null</code> or empty */ public static Properties splitArrayElementsIntoProperties(String[] array, String delimiter, String charsToDelete) { if (ObjectUtils.isEmpty(array)) { return null; } final Properties result = new Properties(); for (String element : array) { if (charsToDelete != null) { element = StringUtils.deleteAny(element, charsToDelete); } final String[] splittedElement = StringUtils.split(element, delimiter); if (splittedElement == null) { continue; } result.setProperty(splittedElement[0].trim(), splittedElement[1].trim()); } return result; } /** * Test if the given String starts with the specified prefix, ignoring upper/lower case. * * @param str * the String to check * @param prefix * the prefix to look for * @return <code>true</code> if given String starts with the specified suffix, <code>false</code> otherwise * @see java.lang.String#startsWith */ public static boolean startsWithIgnoreCase(String str, String prefix) { if ((str == null) || (prefix == null)) { return false; } if (str.startsWith(prefix)) { return true; } if (str.length() < prefix.length()) { return false; } final String lcStr = str.substring(0, prefix.length()).toLowerCase(); final String lcPrefix = prefix.toLowerCase(); return lcStr.equals(lcPrefix); } /** * Strip the filename extension from the given path, e.g. "mypath/myfile.txt" -> "mypath/myfile". * * @param path * the file path (may be <code>null</code>) * @return the path with stripped filename extension, or <code>null</code> if none */ public static String stripFilenameExtension(String path) { if (path == null) { return null; } final int extIndex = path.lastIndexOf(StringUtils.EXTENSION_SEPARATOR); if (extIndex == -1) { return path; } final int folderIndex = path.lastIndexOf(StringUtils.FOLDER_SEPARATOR); if (folderIndex > extIndex) { return path; } return path.substring(0, extIndex); } /** * Test whether the given string matches the given substring at the given index. * * @param str * the original string (or StringBuilder) * @param index * the index in the original string to start matching against * @param substring * the substring to match at the given index * @return <code>true</code> if the given string matches the given substring at the given index, <code>false</code> otherwise */ public static boolean substringMatch(CharSequence str, int index, CharSequence substring) { for (int j = 0; j < substring.length(); j++) { final int i = index + j; if ((i >= str.length()) || (str.charAt(i) != substring.charAt(j))) { return false; } } return true; } /** * Tokenize the given String into a String array via a StringTokenizer. Trims tokens and omits empty tokens. * <p> * The given delimiters string is supposed to consist of any number of delimiter characters. Each of those characters can be used to * separate tokens. A delimiter is always a single character; for multi-character delimiters, consider using * <code>delimitedListToStringArray</code> * * @param str * the String to tokenize * @param delimiters * the delimiter characters, assembled as String (each of those characters is individually considered as delimiter). * @return an array of the tokens * @see java.util.StringTokenizer * @see java.lang.String#trim() * @see #delimitedListToStringArray */ public static String[] tokenizeToStringArray(String str, String delimiters) { return StringUtils.tokenizeToStringArray(str, delimiters, true, true); } /** * Tokenize the given String into a String array via a StringTokenizer. * <p> * The given delimiters string is supposed to consist of any number of delimiter characters. Each of those characters can be used to * separate tokens. A delimiter is always a single character; for multi-character delimiters, consider using * <code>delimitedListToStringArray</code> * * @param str * the String to tokenize * @param delimiters * the delimiter characters, assembled as String (each of those characters is individually considered as delimiter) * @param trimTokens * trim the tokens via String's <code>trim</code> * @param ignoreEmptyTokens * omit empty tokens from the result array (only applies to tokens that are empty after trimming; StringTokenizer will not * consider subsequent delimiters as token in the first place). * @return an array of the tokens (<code>null</code> if the input String was <code>null</code>) * @see java.util.StringTokenizer * @see java.lang.String#trim() * @see #delimitedListToStringArray */ public static String[] tokenizeToStringArray(String str, String delimiters, boolean trimTokens, boolean ignoreEmptyTokens) { if (str == null) { return null; } final StringTokenizer st = new StringTokenizer(str, delimiters); final List<String> tokens = new ArrayList<String>(); while (st.hasMoreTokens()) { String token = st.nextToken(); if (trimTokens) { token = token.trim(); } if (!ignoreEmptyTokens || (token.length() > 0)) { tokens.add(token); } } return StringUtils.toStringArray(tokens); } /** * Determine the RFC 3066 compliant language tag, as used for the HTTP "Accept-Language" header. * * @param locale * the Locale to transform to a language tag * @return the RFC 3066 compliant language tag as String */ public static String toLanguageTag(Locale locale) { return locale.getLanguage() + (StringUtils.hasText(locale.getCountry()) ? "-" + locale.getCountry() : ""); } /** * Copy the given Collection into a String array. The Collection must contain String elements only. * * @param collection * the Collection to copy * @return the String array (<code>null</code> if the passed-in Collection was <code>null</code>) */ public static String[] toStringArray(Collection<String> collection) { if (collection == null) { return null; } return collection.toArray(new String[collection.size()]); } /** * Copy the given Enumeration into a String array. The Enumeration must contain String elements only. * * @param enumeration * the Enumeration to copy * @return the String array (<code>null</code> if the passed-in Enumeration was <code>null</code>) */ public static String[] toStringArray(Enumeration<String> enumeration) { if (enumeration == null) { return null; } final List<String> list = Collections.list(enumeration); return list.toArray(new String[list.size()]); } /** * Trim <i>all</i> whitespace from the given String: leading, trailing, and inbetween characters. * * @param str * the String to check * @return the trimmed String * @see java.lang.Character#isWhitespace */ public static String trimAllWhitespace(String str) { if (!StringUtils.hasLength(str)) { return str; } final StringBuilder sb = new StringBuilder(str); int index = 0; while (sb.length() > index) { if (Character.isWhitespace(sb.charAt(index))) { sb.deleteCharAt(index); } else { index++; } } return sb.toString(); } /** * Trim the elements of the given String array, calling <code>String.trim()</code> on each of them. * * @param array * the original String array * @return the resulting array (of the same size) with trimmed elements */ public static String[] trimArrayElements(String[] array) { if (ObjectUtils.isEmpty(array)) { return new String[0]; } final String[] result = new String[array.length]; for (int i = 0; i < array.length; i++) { final String element = array[i]; result[i] = (element != null ? element.trim() : null); } return result; } /** * Trim all occurences of the supplied leading character from the given String. * * @param str * the String to check * @param leadingCharacter * the leading character to be trimmed * @return the trimmed String */ public static String trimLeadingCharacter(String str, char leadingCharacter) { if (!StringUtils.hasLength(str)) { return str; } final StringBuilder sb = new StringBuilder(str); while ((sb.length() > 0) && (sb.charAt(0) == leadingCharacter)) { sb.deleteCharAt(0); } return sb.toString(); } /** * Trim leading whitespace from the given String. * * @param str * the String to check * @return the trimmed String * @see java.lang.Character#isWhitespace */ public static String trimLeadingWhitespace(String str) { if (!StringUtils.hasLength(str)) { return str; } final StringBuilder sb = new StringBuilder(str); while ((sb.length() > 0) && Character.isWhitespace(sb.charAt(0))) { sb.deleteCharAt(0); } return sb.toString(); } /** * Trim all occurences of the supplied trailing character from the given String. * * @param str * the String to check * @param trailingCharacter * the trailing character to be trimmed * @return the trimmed String */ public static String trimTrailingCharacter(String str, char trailingCharacter) { if (!StringUtils.hasLength(str)) { return str; } final StringBuilder sb = new StringBuilder(str); while ((sb.length() > 0) && (sb.charAt(sb.length() - 1) == trailingCharacter)) { sb.deleteCharAt(sb.length() - 1); } return sb.toString(); } /** * Trim trailing whitespace from the given String. * * @param str * the String to check * @return the trimmed String * @see java.lang.Character#isWhitespace */ public static String trimTrailingWhitespace(String str) { if (!StringUtils.hasLength(str)) { return str; } final StringBuilder sb = new StringBuilder(str); while ((sb.length() > 0) && Character.isWhitespace(sb.charAt(sb.length() - 1))) { sb.deleteCharAt(sb.length() - 1); } return sb.toString(); } /** * Trim leading and trailing whitespace from the given String. * * @param str * the String to check * @return the trimmed String * @see java.lang.Character#isWhitespace */ public static String trimWhitespace(String str) { if (!StringUtils.hasLength(str)) { return str; } final StringBuilder sb = new StringBuilder(str); while ((sb.length() > 0) && Character.isWhitespace(sb.charAt(0))) { sb.deleteCharAt(0); } while ((sb.length() > 0) && Character.isWhitespace(sb.charAt(sb.length() - 1))) { sb.deleteCharAt(sb.length() - 1); } return sb.toString(); } /** * Uncapitalize a <code>String</code>, changing the first letter to lower case as per {@link Character#toLowerCase(char)}. No other * letters are changed. * * @param str * the String to uncapitalize, may be <code>null</code> * @return the uncapitalized String, <code>null</code> if null */ public static String uncapitalize(String str) { return StringUtils.changeFirstCharacterCase(str, false); } /** * Unqualify a string qualified by a '.' dot character. For example, "this.name.is.qualified", returns "qualified". * * @param qualifiedName * the qualified name * @return the unqualified version of the string */ public static String unqualify(String qualifiedName) { return StringUtils.unqualify(qualifiedName, '.'); } /** * Unqualify a string qualified by a separator character. For example, "this:name:is:qualified" returns "qualified" if using a ':' * separator. * * @param qualifiedName * the qualified name * @param separator * the separator * @return the unqualified version of the string */ public static String unqualify(String qualifiedName, char separator) { return qualifiedName.substring(qualifiedName.lastIndexOf(separator) + 1); } private static void validateLocalePart(String localePart) { for (int i = 0; i < localePart.length(); i++) { final char ch = localePart.charAt(i); if ((ch != '_') && (ch != ' ') && !Character.isLetterOrDigit(ch)) { throw new IllegalArgumentException( "Locale part \"" + localePart + "\" contains invalid characters"); } } } }