多线程笔试题目专题

一、基于阻塞队列实现生产者和消费者循环生产消费。

1、解题思路基于自定义线程+ArrayBlockQuery实现

  1.1 生产者

package com.boot.skywalk.util.queue;

import java.util.concurrent.BlockingQueue;

public class Producer implements Runnable{
    private BlockingQueue<Menu> blockingQueue;

    public Producer(BlockingQueue blockingQueue){
        this.blockingQueue=blockingQueue;
    }

    @Override
    public void run() {
        for(int i=1;i<=100;i++){
            Menu menu = new Menu(i + "code");
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            try {
                blockingQueue.put(menu);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            System.out.println("生产商品:"+menu.getMessage());
        }
        // 作为退出标记
        Menu exit = new Menu("exit");
        try {
            blockingQueue.put(exit);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
    }
}

  1.2 消费者

package com.boot.skywalk.util.queue;

import java.util.concurrent.BlockingQueue;

public class Consumer implements Runnable{
    private BlockingQueue<Menu> blockingQueue;

    public Consumer(BlockingQueue blockingQueue){
        this.blockingQueue=blockingQueue;
    }
    @Override
    public void run() {
        Menu menu;
        try {
            while(!(menu=blockingQueue.take()).getMessage().equals("exit")){
                 Thread.sleep(100);
                System.out.println("消费商品:"+menu.getMessage());
            }
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
    }
}

  1.3 测试代码

package com.boot.skywalk.util.queue;

public class Menu {
    private String message;

    public Menu(String message) {
        this.message = message;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

package com.boot.skywalk.util.queue;

import java.util.concurrent.ArrayBlockingQueue;

public class Client {
    public static void main(String[] args) throws InterruptedException {
        ArrayBlockingQueue<Object> blockingQueue = new ArrayBlockingQueue<>(10);
        Producer producer = new Producer(blockingQueue);
        Consumer consumer = new Consumer(blockingQueue);
        System.out.println("消费开始");
        Thread produceThread = new Thread(producer);
        Thread consumerThread = new Thread(consumer);
        produceThread.start();
        consumerThread.start();
        produceThread.join();
        consumerThread.join();
        System.out.println("消费结束");
    }
}

 运行结果

二、多个线程顺序执行

1、解题思路基于CountDownLatch的countDown和await实现.

package co