模拟多线程操作

public class Demo14 {
private static int number=20;
public synchronized int dec() {
if(number==0) {
throw new RuntimeException("GameOver");
}
//模拟线程切换
Thread.yield();
return number--;
}
public static void main(String [] args) {
Demo14 d=new Demo14();
//创建4个线程
for(int i=0;i<4;i++) {
new Thread(new Runnable() {
public void run() {
while(true) {
//调用减得方法
System.out.println(Thread.currentThread().getName()+",number==>"+d.dec());
}
}
}).start();
}
}
}