JAVA生产者消费者(线程同步)代码学习示例

一、问题描述

生产者消费者问题是一个典型的线程同步问题。生产者生产商品放到容器中，容器有一定的容量（只能顺序放，先放后拿），消费者消费商品，当容器满了后，生产者等待，当容器为空时，消费者等待。当生产者将商品放入容器后，通知消费者；当消费者拿走商品后，通知生产者。

二、解决方案

对容器资源加锁，当取得锁后，才能对互斥资源进行操作。

 

复制代码代码如下:

public class ProducerConsumerTest {

    public static void main(String []args){
        Container con = new Container();
        Producer p = new Producer(con);
        Consumer c = new Consumer(con);
        new Thread(p).start();
        new Thread(c).start();
    }

 

}

class Goods{
    int id;
    public Goods(int id){
        this.id=id;
    }

    public String toString(){
        return "商品"+this.id;
    }
}

class Container{//容器采用栈，先进后出
    private int index = 0;
    Goods[] goods = new Goods[6];

    public synchronized void push(Goods good){
        while(index==goods.length){//当容器满了，生产者等待
            try {
                wait();
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        goods[index]=good;
        index++;
        notifyAll();//当生产者放入商品后通知消费者
    }

    public synchronized Goods pop(){
        while(index==0){//当容器内没有商品是等待
            try {
                wait();
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        index--;
        notifyAll();//当消费者消费了商品后通知生产者
        return goods[index];
    }
}

class Producer implements Runnable{

    Container con = new Container();
    public Producer(Container con){
        this.con=con;
    }

    public void run(){
        for(int i=0; i<20; i++){
            Goods good = new Goods(i);
            con.push(good);
            System.out.println("生产了："+good);
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

}

class Consumer implements Runnable{

    Container con = new Container();
    public Consumer(Container con){
        this.con=con;
    }

    public void run(){
        for(int i=0; i<20; i++){
            Goods good=con.pop();
            System.out.println("消费了："+good);
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    
}