Here you can find the source of generatePassword()
public static String generatePassword()
//package com.java2s; //License from project: Apache License import java.util.Random; public class Main { public static String generatePassword() { int[] array = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }; Random rand = new Random(); for (int i = 10; i > 1; i--) { int index = rand.nextInt(i); int tmp = array[index]; array[index] = array[i - 1]; array[i - 1] = tmp;// w w w . j a v a2 s. c om } int result = 0; for (int i = 0; i < 6; i++) result = result * 10 + array[i]; return String.valueOf(result); } }