编辑代码

class TestSYN2 {
    public static void main(String[] agrs) throws Exception{
        myrunable2 my2=new myrunable2();
        Thread th1=new Thread(my2,"窗口1");
        Thread th2=new Thread(my2,"窗口2");
        Thread th3=new Thread(my2,"窗口3");
        th1.start();
        th2.start();
        th3.start();

    }
}
class myrunable2 implements Runnable{
    int ticket=50;
    int count = 0;//计数器
    Object obj=new Object();

    @Override
    public void run() {
        while(true){
            synchronized(obj){//在这里加锁
                if(ticket<=0)
                    return;
                else
                {
                    try {
                        Thread.sleep(100);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }

                    if(count % 3 == 0 && Thread.currentThread().getName() == "窗口1"){
                        System.out.println(Thread.currentThread().getName()+"：在售卖第"+ticket--+"票");
                        count ++;
                    }else if(count % 3 == 1 && Thread.currentThread().getName() == "窗口2"){
                        System.out.println(Thread.currentThread().getName()+"：在售卖第"+ticket--+"票");
                        count ++;
                    }else if(count % 3 == 2 && Thread.currentThread().getName() == "窗口3"){
                        System.out.println(Thread.currentThread().getName()+"：在售卖第"+ticket--+"票");
                        count ++;
                    }

                }

                obj.notify();
                if(ticket<=0)
                    break;

                try {
                    obj.wait(); // 当前线程进入等待状态并释放锁
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

            }

        }
    }
}