随机产生20个字符串并且字符串不能重复 且进行排序

package com.test.kaoshi;

import java.util.HashSet;

import java.util.Iterator;

import java.util.Random;

import java.util.Set;

import java.util.TreeSet;

public class RadomDemo {

/**

* 随机产生20个字符串并且字符串不能重复 且进行排序

* @param random

* @param len

* @return

*/

public Set getChar(){

Set numberSet01 = new HashSet();

Random rdm = new Random();

char ch;

while(numberSet01.size()<20){

int rdGet = Math.abs(rdm.nextInt())%26+97;//产生97到122的随机数a-z值

ch=(char)rdGet;

numberSet01.add(ch);

//Set中是不能放进重复的值的，当它有20个时，就满足你的条件了

}

return numberSet01;

}

public static void main(String[] args) {

RadomDemo rd = new RadomDemo();

Set numberSet01=rd.getChar();

Set numberSet = new TreeSet();

numberSet.addAll(numberSet01);

for(Iterator it=numberSet01.iterator();it.hasNext();){

System.out.print(it.next());

}

System.out.println();

for(Iterator it=numberSet.iterator();it.hasNext();){

System.out.print(it.next());

}

}

}