Java Using Apache Jar : Random String from specific characters

Apache came with implementation in creating a random value using the RandomStringUtils class.

 RandomStringUtils : Operations for random Strings.

Creates a random string whose length is the number of characters specified.


public static String random(int count, String chars)

Creates a random string whose length is the number of characters specified. Characters will be chosen from the set of characters specified.

Parameters:

count - the length of random string to create

chars - the String containing the set of characters to use, may be null

Returns:

the random string

Throws:

IllegalArgumentException - if count < 0.

Example: RandomStringUtils.random(6, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890+-*/!@#$%^&*()");

The above example gives the random string whose length is 6.

Refer the URL for more details http://commons.apache.org/lang/api-2.4/org/apache/commons/lang/RandomStringUtils.html