学步园

原文：java随机生成4位短信验证码工具类分享

源代码下载：http://www.zuidaima.com/share/1550463418092544.htm

package com.zuidaima.random,util;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;

/**
*@author www.zuidaima.com
**/
public class RandomTest { 
public static void main(String[] args) { 
	 String[] beforeShuffle = new String[] { "2", "3", "4", "5", "6", "7",  
             "8", "9", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J",  
             "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",  
             "W", "X", "Y", "Z" };  
     List list = Arrays.asList(beforeShuffle);  
     Collections.shuffle(list);  
     StringBuilder sb = new StringBuilder();  
     for (int i = 0; i < list.size(); i++) {  
         sb.append(list.get(i));  
     }  
     String afterShuffle = sb.toString();  
     String result = afterShuffle.substring(5, 9);  
    System.out .print(result) ;
}}