java线程中典型的生产者与消费者模式

模型描述：
    java线程中典型的生产者与消费者模式，综合运用到thread中的notify()和wait();
仓库Godown的固定的容量大小max_size,同时有多个生产者向仓库生产放他产品，同时又有多个消费都从仓库取出产品，这就涉及到生产和消费过程中的同步问题，利用多线程技术可以很好的解决这个问题

1、生产者模型，定义为一个线程即实现Thread类

package com.leiht.thread.waitnotify;

public class Producer extends Thread {
	
	private int needNum;
	private Godown godown;
	
	public Producer(int needNum, Godown godown) {
		this.needNum = needNum;
		this.godown = godown;
	}
	

	@Override
	public void run() {
		godown.produce(needNum);
	}
	

	public int getNeedNum() {
		return needNum;
	}

	public void setNeedNum(int needNum) {
		this.needNum = needNum;
	}

	public Godown getGodown() {
		return godown;
	}

	public void setGodown(Godown godown) {
		this.godown = godown;
	}

}

2、消费模型

package com.leiht.thread.waitnotify;

public class Consumer extends Thread {
	
	private int needNum;
	private Godown godown;
	
	public Consumer(int needNum, Godown godown) {
		this.needNum = needNum;
		this.godown = godown;
	}
	
	@Override
	public void run() {
		godown.consume(needNum);
	}
	
	
	public int getNeedNum() {
		return needNum;
	}

	public void setNeedNum(int needNum) {
		this.needNum = needNum;
	}

	public Godown getGodown() {
		return godown;
	}

	public void setGodown(Godown godown) {
		this.godown = godown;
	}
	
}

仓库模型（核心代码）

package com.leiht.thread.waitnotify;

public class Godown {

	public int current_size;
	public static final int max_size = 100;

	public static int getMaxSize() {
		return max_size;
	}
	
	public Godown(int current_size) {
		this.current_size = current_size;
	}
	
	/*
	 * 生产方法
	 */
	public synchronized void produce(int needNum) {
		//可以生产
		if((needNum + current_size) < max_size) { 
			System.out.println("开始生产");
			current_size = current_size + needNum;
			System.out.println("生产完成");
			notifyAll();
			
		}else { //不能生产 将当前线程挂到this（当前）对象上
			try {
				System.out.println("当前库存过大，挂起等待");
				wait();
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
	}
	
	/*
	 * 消费方法
	 */
	public synchronized void consume(int needNum) {
		
		if(needNum > current_size) {
			try {
				System.out.println("当前商品不足，等等待");
				wait();
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
		System.out.println("开始消费");
		current_size = current_size - needNum;
		System.out.println("结束消费");
		notifyAll();
		
	}

}

测试代码

package com.leiht.thread.waitnotify;

public class Test  {
	public static void main(String[] args) {
		Godown godown = new Godown(30);
		Consumer c1 = new Consumer(50, godown);
		Consumer c2 = new Consumer(20, godown);
		Consumer c3 = new Consumer(30, godown);
		Producer p1 = new Producer(10, godown);
		Producer p2 = new Producer(10, godown);
		Producer p3 = new Producer(10, godown);
		Producer p4 = new Producer(10, godown);
		Producer p5 = new Producer(10, godown);
		Producer p6 = new Producer(10, godown);
		Producer p7 = new Producer(80, godown);
		c1.start();
		c2.start();
		c3.start();
		p1.start();
		p2.start();
		p3.start();
		p4.start();
		p5.start();
		p6.start();
		p7.start();
	}
}

评论

1 楼 sql_861365880 2015-11-02