Example usage for java.lang Character isLetter

Introduction

In this page you can find the example usage for java.lang Character isLetter.

Prototype

public static boolean isLetter(int codePoint)

Source Link

Document

Determines if the specified character (Unicode code point) is a letter.

Usage

From source file:bfile.util.StringUtils.java

/**
 * <p>Checks if the CharSequence contains only Unicode letters.</p>
 *
 * <p>{@code null} will return {@code false}.
 * An empty CharSequence (length()=0) will return {@code false}.</p>
 *
 * <pre>/* w w w . ja  v  a  2  s. co m*/
 * 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 signature from isAlpha(String) to isAlpha(CharSequence)
 * @since 3.0 Changed "" to return false and not true
 */
public static boolean isAlpha(final CharSequence cs) {
    if (isEmpty(cs)) {
        return false;
    }
    final int sz = cs.length();
    for (int i = 0; i < sz; i++) {
        if (Character.isLetter(cs.charAt(i)) == false) {
            return false;
        }
    }
    return true;
}

From source file:bfile.util.StringUtils.java

/**
 * <p>Checks if the CharSequence contains only Unicode letters and
 * space (' ').</p>// ww  w .  j ava 2 s  .  c  o  m
 *
 * <p>{@code null} will return {@code false}
 * An empty CharSequence (length()=0) will return {@code true}.</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(final CharSequence cs) {
    if (cs == null) {
        return false;
    }
    final int sz = cs.length();
    for (int i = 0; i < sz; i++) {
        if (Character.isLetter(cs.charAt(i)) == false && cs.charAt(i) != ' ') {
            return false;
        }
    }
    return true;
}

From source file:com.clark.func.Functions.java

/**
 * <p>/*from  w  ww .  ja  v a 2  s .c  o m*/
 * Creates a random string based on a variety of options, using supplied
 * source of randomness.
 * </p>
 * 
 * <p>
 * If start and end are both <code>0</code>, start and end are set to
 * <code>' '</code> and <code>'z'</code>, the ASCII printable characters,
 * will be used, unless letters and numbers are both <code>false</code>, in
 * which case, start and end are set to <code>0</code> and
 * <code>Integer.MAX_VALUE</code>.
 * 
 * <p>
 * If set is not <code>null</code>, characters between start and end are
 * chosen.
 * </p>
 * 
 * <p>
 * This method accepts a user-supplied {@link Random} instance to use as a
 * source of randomness. By seeding a single {@link Random} instance with a
 * fixed seed and using it for each call, the same random sequence of
 * strings can be generated repeatedly and predictably.
 * </p>
 * 
 * @param count
 *            the length of random string to create
 * @param start
 *            the position in set of chars to start at
 * @param end
 *            the position in set of chars to end before
 * @param letters
 *            only allow letters?
 * @param numbers
 *            only allow numbers?
 * @param chars
 *            the set of chars to choose randoms from. If <code>null</code>,
 *            then it will use the set of all chars.
 * @param random
 *            a source of randomness.
 * @return the random string
 * @throws ArrayIndexOutOfBoundsException
 *             if there are not <code>(end - start) + 1</code> characters in
 *             the set array.
 * @throws IllegalArgumentException
 *             if <code>count</code> &lt; 0.
 * @since 2.0
 */
public static String random(int count, int start, int end, boolean letters, boolean numbers, char[] chars,
        Random random) {
    if (count == 0) {
        return "";
    } else if (count < 0) {
        throw new IllegalArgumentException("Requested random string length " + count + " is less than 0.");
    }
    if ((start == 0) && (end == 0)) {
        end = 'z' + 1;
        start = ' ';
        if (!letters && !numbers) {
            start = 0;
            end = Integer.MAX_VALUE;
        }
    }

    char[] buffer = new char[count];
    int gap = end - start;

    while (count-- != 0) {
        char ch;
        if (chars == null) {
            ch = (char) (random.nextInt(gap) + start);
        } else {
            ch = chars[random.nextInt(gap) + start];
        }
        if ((letters && Character.isLetter(ch)) || (numbers && Character.isDigit(ch))
                || (!letters && !numbers)) {
            if (ch >= 56320 && ch <= 57343) {
                if (count == 0) {
                    count++;
                } else {
                    // low surrogate, insert high surrogate after putting it
                    // in
                    buffer[count] = ch;
                    count--;
                    buffer[count] = (char) (55296 + random.nextInt(128));
                }
            } else if (ch >= 55296 && ch <= 56191) {
                if (count == 0) {
                    count++;
                } else {
                    // high surrogate, insert low surrogate before putting
                    // it in
                    buffer[count] = (char) (56320 + random.nextInt(128));
                    count--;
                    buffer[count] = ch;
                }
            } else if (ch >= 56192 && ch <= 56319) {
                // private high surrogate, no effing clue, so skip it
                count++;
            } else {
                buffer[count] = ch;
            }
        } else {
            count++;
        }
    }
    return new String(buffer);
}