package com.companyname.common.test;

import java.util.ArrayList;
import java.util.Random;

/**
 * @Description 獲取 10 個 1-20 之間的隨機數，要求不能重復
 * @Author Created by shusheng.
 * @Email [email protected]
 * @Date 2018/12/14
 */
public class RandomDemo {

    public static void main(String[] args) {

        Random random 
 
= new Random();

        ArrayList<Integer> arrayList = new ArrayList<Integer>();

        int x=0;

        while(x<10){
            int y = random.nextInt(20);
            if(!arrayList.contains(y)){
                arrayList.add(y);
                x++;
            }
        }

        
 
for(Integer i:arrayList){
            System.out.println(i);
        }

    }
}

【ArrayList：獲取 10 個 1-20 之間的隨機數，要求不能重復】