import java.util.ArrayList;

 import java.util.Collections;

 import java.util.Random;

 public class raffle {

     private ArrayList<Integer> list;

     private void deal(){

         //向list容器中顺序添加指定数量num的整数

         if (list==null) {

             list = new ArrayList<Integer>();

             for (int i = 1; i < 1000; i++) {

                 list.add(i);

             }

         }

         //打乱list中元素顺序

         Collections.shuffle(list);

     }

     //抽奖的方法：抽出指定数量的奖项

     public void draw(){

         Random rdom = new Random();

         int index = rdom.nextInt(list.size());

         System.out.println("一等奖："+list.get(index));

         list.remove(index);

         Collections.shuffle(list);

         for (int i = 0; i < 2; i++) {

             int index2 = rdom.nextInt(list.size());

             System.out.println("二等奖："+list .get(index2));

             list.remove(index2);

         }

         Collections.shuffle(list);

         for (int i = 0; i < 3; i++) {

             int index3 = rdom.nextInt(list.size());

             System.out.println("三等奖："+list .get(index3));

             list.remove(index3);

         }

         Collections.shuffle(list);

     }

     public static void main(String[] args) {

         // TODO Auto-generated method stub

         raffle rf = new raffle();

         rf.deal();

         rf.draw();

     }

 }