package com.test;import java.util.Random;
import java.util.UUID;
import java.util.concurrent.ThreadLocalRandom;public class M1001{public static void main(String[] args) {System.out.println("-----------产生5个随机数的验证码----------------");String code = UUID.randomUUID().toString().substring(0, 5);System.out.println(code);System.out.println("------------产生指定的随机数---------------");String str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";str += str.toLowerCase();str += "0123456789";StringBuilder sb = new StringBuilder(5);for(int i=0; i < 5; i++){char ch = str.charAt(new Random().nextInt(str.length()));sb.append(ch);}System.out.println(sb);}
}