java 多线程-信号灯法

借助标志位

public class light {
public static void main(String[]args)
{
	Tv tv=new Tv();
	new Player(tv).start();
	new Watcher(tv).start();
}

}
//生产者 演员
class Player extends Thread{
Tv tv;
public Player(Tv tv)
{
	this.tv=tv;
}
public void run()
{
	for(int i=0;i<20;i++)
	{
		if(i%2==0)
		{
			this.tv.play("偶不变");
		}else
		{
			this.tv.play("奇变");
		}
	}
}
}
//消费者 观众
class Watcher extends Thread{
Tv tv;
public Watcher(Tv tv)
{
	this.tv=tv;
}
public void run()
{
	for(int i=0;i<20;i++)
	{
		this.tv.watch("无聊");
	}
}
}
//同一个资源 电视
	class Tv {

String voice;
//信号灯
//为真则演员表演，观众等待
//为假则观众观看，演员等待

boolean flag=true;

//表演
public synchronized void play(String voice)
{
	if(!flag)
	{
		try {
			this.wait();
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	System.out.println("表演了:"+voice);
	this.voice=voice;
	
	//表演后
	this.notifyAll();
	this.flag=!this.flag;
}

public void watch(String string) {
	// TODO Auto-generated method stub
	
}

//观看
public synchronized void watch()
{
	if(flag)
	{
		try {
			this.wait();
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	System.out.println("听到了:"+voice);
	
	//观看后:
	this.notifyAll();
	this.flag=!this.flag;
}
}