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;
    }

}