how to generate random string in java

/**
 * @author lautturi.com 
 * Java example: generate a random string in java
 */

import java.util.*;

public class Lautturi {
	
	public static void main(String[] args) {
		String chars = "0123456789"
                + "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                + "abcdefghijklmnopqrstuvwxyz"
                + "!@#$%&-=+";
		int len = 15;
		
        Random rnd = new Random();
        String randomString = "";
        for (int i = 0; i < len; i++)
        	randomString += chars.charAt(rnd.nextInt(chars.length()));
	        // or
	        // randomString += chars.toCharArray()[rnd.nextInt(chars.length())];
		System.out.println("random string:"+ randomString);
	}
}

output:

random string:o8#j6!9n3RDgoF&