Java: Method Radom String - Reset radom password

Radom method

Java 2016

package com.giaima;

import java.security.SecureRandom;

public class RadomString {

    static final String AB = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
    static SecureRandom rnd = new SecureRandom();

    String randomString(int len) {
        StringBuilder sb = new StringBuilder(len);
        for (int i = 0; i < len; i++) {
            sb.append(AB.charAt(rnd.nextInt(AB.length())));
        }
        return sb.toString();
    }
    //Test
    public static void main(String[] args) {
        RadomString r = new RadomString();
        System.out.println(r.randomString(6));
    }
}