Java Random String randomString(int length)

Description

random String

License

Open Source License

Declaration

public static final String randomString(int length) 

Method Source Code

//package com.java2s;
/*//from   w  ww.  j  a va 2 s. c  o  m
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

import java.util.*;

public class Main {
    /**
     * Pseudo-random number generator object for use with randomString(). The
     * Random class is not considered to be cryptographically secure, so only
     * use these random Strings for low to medium security applications.
     */
    private static Random randGen = new Random();
    /**
     * Array of numbers and letters of mixed case. Numbers appear in the list
     * twice so that there is a more equal chance that a number will be picked.
     * We can use the array to get a random number or letter by picking a random
     * array index.
     */
    private static char[] numbersAndLetters = ("0123456789abcdefghijklmnopqrstuvwxyz"
            + "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ").toCharArray();

    public static final String randomString(int length) {
        if (length < 1) {
            return null;
        }
        // Create a char buffer to put random letters and numbers in.
        char[] randBuffer = new char[length];
        for (int i = 0; i < randBuffer.length; i++) {
            randBuffer[i] = numbersAndLetters[randGen.nextInt(71)];
        }
        return new String(randBuffer);
    }

    public static final String randomString(final String prefix, int length) {
        return (prefix + randomString(length));
    }
}

Related

1. randomString()
2. randomString(final int length)
3. randomString(int len)
4. randomString(int length)
5. randomString(int length)
6. randomString(int length)
7. randomString(int length)
8. randomString(int length)
9. randomstring(int lo, int hi)