java 多线程生产者与消费者

 1.主要使用notifyAll和wait完成线程之间的通信

2.使用注意事项notifyAll和wait必须在同步代码块中使用,也可以是同步方法并且notifyAll和wait必须使用同一个锁对象进行操作,wait不能用if判断必须用while循环判断 防止虚假唤醒

1.首先创建一个共享仓库,仓库里存储的是手机

import java.util.ArrayList;
import java.util.List;

public class Depository {
    private List<Phone> phoneList = new ArrayList();


    public List<Phone> getPhoneList() {

        return phoneList;
    }

    public void setPhoneList(List<Phone> phoneList) {
        this.phoneList = phoneList;
    }

    @Override
    public String toString() {
        return "PhoneDepository{" +
                "phoneList=" + phoneList +
                '}';
    }

    public class Phone{
        private String name;
        private float price;

        public Phone(String name, float price) {
            this.name = name;
            this.price = price;
        }

        @Override
        public String toString() {
            return "Phone{" +
                    "name='" + name + '\'' +
                    ", price='" + price + '\'' +
                    '}';
        }
    }
}

2.创建一个生产者

package com.yujie.pool.producer;

import com.yujie.pool.utils.Sleep;

import java.util.List;
import java.util.Random;


public class Producer implements Runnable{
    private Depository depository;

    public Producer(Depository depository) {
        if(depository == null){
            throw new NullPointerException("仓库不能为空");
        }
        this.depository = depository;
    }

    @Override
    public void run() {
        List<Depository.Phone> phoneList = depository.getPhoneList();
        while (true){
            synchronized (depository) {
                //这里不能用if防止虚假唤醒,如果有库存就等待
                while (phoneList.size() != 0){
                    try {
                        depository.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
                Depository depository = new Depository();
                phoneList.add(depository.new Phone("小米5",new Random().nextInt(1888)));
                phoneList.add(depository.new Phone("苹果6",new Random().nextInt(1888)));
                for (Depository.Phone phone : phoneList) {
                    System.out.println("生产手机:"+phone);
                }
                System.out.println("生产手机,目前生产数量:" + phoneList.size());
                System.out.println("==============生产结束================");
                this.depository.notifyAll();

            }
        }
    }
}

3.创建一个消费者

package com.yujie.pool.producer;

import com.yujie.pool.utils.Sleep;

import java.util.List;

public class Consumer implements Runnable {
    private Depository depository;

     Consumer(Depository depository) {
         if(depository == null){
             throw new NullPointerException("仓库不能为空");
         }
        this.depository = depository;
    }

    @Override
    public void run() {
        List<Depository.Phone> phoneList = depository.getPhoneList();
        while (true){
            synchronized (depository) {
                //这里不能用if防止虚假唤醒,如果没有库存就等待
                while (phoneList.size() == 0){
                    try {
                        depository.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
                for (Depository.Phone phone : phoneList) {
                    System.out.println("卖出:"+phone);
                }
                System.out.println("------------卖出结束------------");
                this.depository.notifyAll();
                phoneList.clear();
            }
        }
    }
}

4.测试

public class TestProducer {
    public static void main(String[] args) {
        Depository depository = new Depository();
        Producer producer = new Producer(depository);
        Consumer consumer = new Consumer(depository);

        new Thread(producer).start();
        new Thread(consumer).start();
    }
}

生产手机:Phone{name='小米5', price='774.0'}
生产手机:Phone{name='苹果6', price='1337.0'}
生产手机,目前生产数量:2
==============生产结束================
卖出:Phone{name='小米5', price='774.0'}
卖出:Phone{name='苹果6', price='1337.0'}
------------卖出结束------------
生产手机:Phone{name='小米5', price='1099.0'}
生产手机:Phone{name='苹果6', price='857.0'}
生产手机,目前生产数量:2
==============生产结束================
卖出:Phone{name='小米5', price='1099.0'}
卖出:Phone{name='苹果6', price='857.0'}
------------卖出结束------------
生产手机:Phone{name='小米5', price='515.0'}
生产手机:Phone{name='苹果6', price='255.0'}
生产手机,目前生产数量:2
==============生产结束================
卖出:Phone{name='小米5', price='515.0'}
卖出:Phone{name='苹果6', price='255.0'}
------------卖出结束------------