生成隨機密碼,密碼規則符合：大寫字母、小寫字母、數字、特殊字符應選三種或以上

package com.payegis.thunder.webapp.admin.util;

import java.util.Random;

public class RandomPasswordUtil {

	/**
	 * 大寫字母、小寫字母、數字、特殊字符彙總
	 * @return
	 */
	public static char[] getChar() {
		char[] passwordLit = new char[67];
		char fword = 'A';
		char mword = 'a';
		char bword = '0';
		for (int i = 0; i < 62; i++) {
			if (i < 26) {
				passwordLit[i] = fword;
				fword++;
			} else if (i < 52) {
				passwordLit[i] = mword;
				mword++;
			} else {
				passwordLit[i] = bword;
				bword++;
			}
		}
		passwordLit[62] = '!';
		passwordLit[63] = '@';
		passwordLit[64] = '#';
		passwordLit[65] = '$';
		passwordLit[66] = '&';

		return passwordLit;
	}

	/**
	 * 生成隨機密碼，密碼規則符合：大寫字母、小寫字母、數字、特殊字符應選三種或以上
	 * @param length
	 * @return
	 */
	public static String getRandomPwdByCondition(int length) {
		char[] r = getChar();
		while (true) {
			String randomPwd = getRandomPwd(r, length);
			int count = 0;
			if (randomPwd.matches(".*[a-z]{1,}.*")){
				++count;
			}
			if (randomPwd.matches(".*[A-Z]{1,}.*")){
				++count;
			}
			if (randomPwd.matches(".*\\d{1,}.*")){
				++count;
			}
			if (randomPwd.matches(".*[!@#$&]{1,}.*")){
				++count;
			}
			if (count >= 3){
				return randomPwd;
			}
		}
	}

	public static String getRandomPwd(char[] r, int length) {
		Random rr = new Random();
		char[] pw = new char[length];
		for (int i = 0; i < pw.length; i++) {
			int num = rr.nextInt(67);
			pw[i] = r[num];
		}

		return String.valueOf(pw);
	}

	public static String getRandomPwd(int length) {
		char[] r = getChar();
		Random rr = new Random();
		char[] pw = new char[length];
		for (int i = 0; i < pw.length; i++) {
			int num = rr.nextInt(67);
			pw[i] = r[num];
		}

		return String.valueOf(pw);
	}

	public static void main(String[] args) {
		System.out.println(getRandomPwdByCondition(8));
	}

}