生產者消費者模式

生產者消費者模式見上圖所示。

blog宗旨:用圖說話。

代碼示例：

package com.huan;


public class ProduceConsumer {
	public static void main(String[] args) {
		Middleware middleware = new Middleware();
		
		new Thread(new Producer(middleware)).start();
		
		new Thread(new Consumer(middleware)).start();
	}
}

class Producer implements Runnable{
	private Middleware middleware;
	public Producer(Middleware middleware){
		this.middleware = middleware;
	}
	
	public void produce() throws Exception{
		while(true){
			middleware.put();
		}
	}

	@Override
	public void run() {
		try {
			produce();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

class Consumer implements Runnable{
	private Middleware middleware;
	public Consumer(Middleware middleware){
		this.middleware = middleware;
	}
	
	public void consume() throws Exception{
		while(true){
			middleware.get();
		}
	}

	@Override
	public void run() {
		try {
			consume();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

class Middleware{
	private static final int MAX_SIZE = 10;
	private int[] storage = new int[MAX_SIZE];
	private int index = 0;
	
	public synchronized void put() throws Exception{
		if(index == MAX_SIZE){
			wait();
		}
		storage[index] = index;
		System.out.println("生產了:" + index);
		index++;
		notify();
	}
	
	public synchronized void get() throws Exception{
		if(index == 0){
			wait();
		}
		index--;
		System.out.println("消費了:" + storage[index]);
		notify();
	}
}

代碼缺陷：當多個消費者時，或者多個生產者時，上例代碼需要完善。