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();
}
}