Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;

import java.util.ArrayList;
import java.util.Collections;

import java.util.List;
import java.util.Random;

public class Main {
    /**
     * This method generates a random n digit password, which contains at least one number, lower case alphabet, upper
     * case alphabet and as special character.
     */
    public static String generatePassword(int n) {

        Random rd = new Random();

        char lowerChars[] = "abcdefghijklmnopqrstuvwxyz".toCharArray();
        char upperChars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
        char numbers[] = "0123456789".toCharArray();
        char specialChars[] = "~!@#$%^&*()-_=+[{]}|;:<>/?".toCharArray();

        List<Character> pwdLst = new ArrayList<Character>();
        for (int g = 0; g < 4; g++) {
            for (int z = 0; z < 1; z++) {
                if (g == 0) {
                    pwdLst.add(numbers[rd.nextInt(10)]);
                } else if (g == 1) {
                    pwdLst.add(lowerChars[rd.nextInt(26)]);
                } else if (g == 2) {
                    pwdLst.add(upperChars[rd.nextInt(26)]);
                } else if (g == 3) {
                    pwdLst.add(specialChars[rd.nextInt(26)]);
                }
            }
            if (pwdLst.size() == n) {
                break;
            }
            if (g + 1 == 4) {
                g = (int) Math.random() * 5;

            }
        }
        StringBuilder password = new StringBuilder();
        Collections.shuffle(pwdLst);
        for (int c = 0; c < pwdLst.size(); c++) {
            password.append(pwdLst.get(c));
        }
        return password.toString();
    }
}