package com.example.demo1.service.impl;

import lombok.Data;

import java.time.LocalDateTime;
import java.time.temporal.ChronoUnit;
import java.util.Date;

@Data
public class User {

    //用户id
    private Integer id;

    //姓名
    private String name;

    //插入的时间
    private LocalDateTime date;


}

package com.example.demo1.service.impl;


import java.time.LocalDateTime;
import java.time.temporal.ChronoUnit;
import java.util.Random;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * 排队任务
 * 5秒内随机进来1个用户
 */
public class PaiDuiTask implements Runnable{

    private AtomicInteger atomicInteger;

    private BlockingQueue<User> blockingQueue;

    public PaiDuiTask(BlockingQueue<User> blockingQueue){
        this.blockingQueue=blockingQueue;
        atomicInteger=new AtomicInteger(0);
    }

    @Override
    public void run() {
        while (true){
            //设置每个用户的随机进来的时间
            int next=new Random().nextInt(5);
            try {
                Thread.sleep(1000*next);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            User user=new User();
            //用户id 自增
            user.setId(atomicInteger.getAndIncrement());
            user.setName("用户"+user.getId());
            //当前时间
            user.setDate(LocalDateTime.now());

            long miao=0;
            if(blockingQueue.peek()!=null){
                //获取队列中第一个元素的时间
                LocalDateTime oneTime=blockingQueue.peek().getDate();
                //当前时间减去队列中的时间 就是需要等待的时间
                miao = ChronoUnit.SECONDS.between(oneTime, user.getDate());
            }
            System.out.println(user.getName()+"进入排队中,需要等待"+miao+"秒");
            //把用户加入到队列中
            try {
                blockingQueue.put(user);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }

        }

    }
}

package com.example.demo1.service.impl;

import java.util.Random;
import java.util.concurrent.BlockingQueue;

/**
 * 抢手机的任务
 * 从队列中取出数据
 */
public class QiangTask implements Runnable{
    private BlockingQueue<User> blockingQueue;
    public QiangTask(BlockingQueue<User> blockingQueue){
        this.blockingQueue=blockingQueue;
    }

    @Override
    public void run() {
        while (true){
            //从队列中取出用户信息
            User user = null;
            try {
                //如果队列是空的 就会一直阻塞
                user = blockingQueue.take();
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            System.out.println(user.getName()+"正在处理");
            try {
                //假设每个用户处理间隔 随机5秒内
                int next=new Random().nextInt(5);
                Thread.sleep(1000*next);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            System.out.println(user.getName()+"处理完成");
        }

    }
}

测试类 定义线程池 把2个任务 放入线程池去执行

一边模拟用户进来，一边模拟用户进行抢购

package com.example.demo1.service.impl;

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class Test {

    //自定义线程池
    public static ThreadPoolExecutor threadPoolExecutor(){
        //核心线程数
        int corePoolSize=20;
        //最大线程数
        int maximumPoolSize=100;
        //存活时间
        long keepAliveTime=60;
        //存活时间单位
        TimeUnit unit=TimeUnit.SECONDS;
        //阻塞队列
        BlockingQueue<Runnable> workQueu=new LinkedBlockingQueue<>(100);
        return new ThreadPoolExecutor(corePoolSize,maximumPoolSize,keepAliveTime,unit,workQueu);
    }

    public static void main(String[] args) {
        //获取线程池
        ThreadPoolExecutor executor=threadPoolExecutor();
        //链表阻塞队列
        BlockingQueue<User> blockingQueue=new LinkedBlockingQueue<>(100);
        //执行排队线程
        executor.execute(new PaiDuiTask(blockingQueue));
        //执行消费任务 抢购手机
        executor.execute(new QiangTask(blockingQueue));

    }
}

 可以看到，在用户等待的时候，会显示需要等待多少秒之后 才能抢到