1.java生成随机不重复10位字符串

 package org.changneng.util;

 import java.util.Random;
 public class A {
     public static void main(String args[]){
              for(int i=0;i<100;i++){
                  System.out.println(GetRandomString(10));
              }
     }

     public static String GetRandomString(int Len) {

         String[] baseString={"0","1","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","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"};
         Random random = new Random();
         int length=baseString.length;
         String randomString="";
         for(int i=0;i<length;i++){
             randomString+=baseString[random.nextInt(length)];
         }
         random = new Random(System.currentTimeMillis());
         String resultStr="";
         for (int i = 0; i < Len; i++) {
             resultStr += randomString.charAt(random.nextInt(randomString.length()-1));
         }
         return resultStr;
     }

 }