Java Random String generateRandomString(final String pattern)

Description

generate Random String

License

Open Source License

Declaration

public static String generateRandomString(final String pattern) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

public class Main {
    private static final char[] LOWER_ALPHA_CHARS = ("abcdefghijklmnopqrstuvwxyz").toCharArray();
    private static final char[] UPPER_ALPHA_CHARS = ("ABCDEFGHIJKLMNOPQRSTUVWXYZ").toCharArray();
    private static final char[] NUMERIC_CHARS = ("0123456789").toCharArray();
    private static final char[] SPECIAL_CHARS = ("!@#$%^&*()").toCharArray();
    private static final char[] ALL_CHARS = ("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
            .toCharArray();/*  ww w  .  j  a  va 2s  .c  o  m*/

    public static String generateRandomString(final String pattern) {

        if ((pattern == null) || (pattern.length() == 0)) {
            return "";
        }
        final char[] patternChars = pattern.toCharArray();
        final StringBuilder retVal = new StringBuilder(pattern.length());
        final java.util.Random rndGen = new java.util.Random();
        for (char patternChar : patternChars) {
            if (patternChar == '#') {
                retVal.append(NUMERIC_CHARS[rndGen.nextInt(NUMERIC_CHARS.length)]);
            } else if (patternChar == 'L') {
                retVal.append(LOWER_ALPHA_CHARS[rndGen.nextInt(LOWER_ALPHA_CHARS.length)]);
            } else if (patternChar == 'U') {
                retVal.append(UPPER_ALPHA_CHARS[rndGen.nextInt(UPPER_ALPHA_CHARS.length)]);
            } else if (patternChar == 'S') {
                retVal.append(SPECIAL_CHARS[rndGen.nextInt(SPECIAL_CHARS.length)]);
            } else if (patternChar == '*') {
                retVal.append(ALL_CHARS[rndGen.nextInt(ALL_CHARS.length)]);
            }
        }
        return retVal.toString();
    }
}

Related

1. generateRandomString()
2. generateRandomString()
3. generateRandomString()
4. generateRandomString()
5. generateRandomString(final int minCharLen, final int maxCharLen)
6. generateRandomString(int count)
7. generateRandomString(int len)
8. generateRandomString(int length)
9. generateRandomString(int length)