java生成随机短信验证码的工具类

public class yanzhengma {
public static void main(String[] args) {
   String[] beforeShuffle = new String[] { "1","2", "3", "4", "5", "6", "7",  
  "8", "9", "0" };  
     List list = Arrays.asList(beforeShuffle); //将数组转成List
     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(3, 9);  
    System.out .print(result) ;
    }
}