Java多线程学习——wait方法（信号灯法/生产者消费者模式）

信号灯法：以一个标志位来判断是否执行还是等待

 

public class TV {
    private String voice;   //内容
    private boolean flag=false;  //信号灯,true表示观众可以看电视啦,false表示演员可以表演啦
    //演员表演
    public synchronized void play(String voice){
        if(flag==true){   //true表示演员等待,观众观看
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        //可以表演,此时flag=false
        System.out.println("表演了"+voice);
        this.voice=voice;
        flag=!flag; //表演完毕,改变flag=true,通知观众观看,同时让演员停止表演
        this.notifyAll();   //通知观众观看
    }
    //观众观看
    public synchronized void watch(){
        if(flag==false){    //false,观众不能观看
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        //可以观看,此时flag=true;
        System.out.println("观看了"+voice);
        flag=!flag; //观看完毕,改变flag=false
        this.notifyAll();
    }
}

 

public class Player implements Runnable{
    private TV tv;

    public Player(TV tv) {
        this.tv = tv;
    }

    @Override
    public void run() {
        for (int i = 0; i < 20; i++) {
            if(i%2==0){
                tv.play("中国好声音:"+i);
            }else{
                tv.play("中国有嘻哈:"+i);
            }
        }
    }
}

 

public class Audience implements Runnable{
    private TV tv;

    public Audience(TV tv) {
        this.tv = tv;
    }

    @Override
    public void run() {
        for (int i = 0; i < 20; i++) {
            tv.watch();
        }
    }
}

 

public class TvTest {
    public static void main(String[] args) {
        TV tv=new TV();
        Player player=new Player(tv);
        Audience audience=new Audience(tv);
        new Thread(player).start();
        new Thread(audience).start();
    }
}