java 多线程& notify()方法：只通知一个线程——72

package chapter3.test3_1.test3_1_13;

public class MyService {
    private Object lock = new Object();

    public void waitMethod() {
        try {
            synchronized (lock) {
                System.out.println("begin wait " + System.currentTimeMillis() + " " + Thread.currentThread().getName());
                lock.wait();
                System.out.println(" end wait " + System.currentTimeMillis() + " " + Thread.currentThread().getName());
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public void notifyMethod() {
        synchronized (lock) {
            System.out.println("begin notify " + System.currentTimeMillis() + " " + Thread.currentThread().getName());
            lock.notify();
            System.out.println(" end notify " + System.currentTimeMillis() + " " + Thread.currentThread().getName());
        }
    }
}

package chapter3.test3_1.test3_1_13;

public class MyThreadA extends Thread {
    private MyService service;

    public MyThreadA(MyService service) {
        super();
        this.service = service;
    }

    @Override
    public void run() {
        service.waitMethod();
    }
}

package chapter3.test3_1.test3_1_13;

public class MyThreadB extends Thread {
    private MyService service;

    public MyThreadB(MyService service) {
        super();
        this.service = service;
    }

    @Override
    public void run() {
        service.notifyMethod();
    }
}

package chapter3.test3_1.test3_1_13;

public class Test {
    public static void main(String[] args) throws InterruptedException {
        MyService service = new MyService();
        for (int i = 0; i < 10; i++) {
            MyThreadA t1 = new MyThreadA(service);
            t1.start();
        }
        Thread.sleep(1000);
        MyThreadB t1 = new MyThreadB(service);
        t1.start();
        Thread.sleep(500);
        MyThreadB t2 = new MyThreadB(service);
        t2.start();
        Thread.sleep(500);
        MyThreadB t3 = new MyThreadB(service);
        t3.start();
        Thread.sleep(500);
        MyThreadB t4 = new MyThreadB(service);
        t4.start();
        Thread.sleep(500);
        MyThreadB t5 = new MyThreadB(service);
        t5.start(); // 一共唤醒5个线程
    }
}

notify() 方法仅按照执行 wait()方法的顺序依次唤醒一个线程，分别是Thread-0 、 Thread-5 、 Thread-4 、 Thread-3 、 Thread-2。