wait和notify使用案例

/**
 * 开启四个线程 两个waitThread和 两个notifyThread 
 * 使用notifyThread唤醒waitThread线程
 */
public class NotifyExample {
    public static void main(String[] args) {
        final Object lock = new Object();

        Thread waitThread1 = new Thread(() -> {
            synchronized (lock) {
                System.out.println(LocalTime.now() +  " " + Thread.currentThread().getName()  +" WaitThread: Going to wait");
                try {
                    lock.wait(); // wait until notified
                } catch (InterruptedException e) {
                    System.out.println(e);
                }
                System.out.println(LocalTime.now() +  " " + Thread.currentThread().getName()   + " WaitThread: Woke up");
            }
        });

        Thread waitThread2 = new Thread(() -> {
            synchronized (lock) {
                System.out.println(LocalTime.now() + " " + Thread.currentThread().getName()   + " WaitThread: Going to wait");
                try {
                    lock.wait(); // wait until notified
                } catch (InterruptedException e) {
                    System.out.println(e);
                }
                System.out.println(LocalTime.now() + " " + Thread.currentThread().getName()   + " WaitThread: Woke up");
            }
        });


        Thread notifyThread1 = new Thread(() -> {
            try {
                Thread.sleep(4000); // sleep for 2 seconds
            } catch (InterruptedException e) {
                System.out.println(e);
            }
            synchronized (lock) {
                System.out.println(LocalTime.now() +  " " + Thread.currentThread().getName()   +  " NotifyThread: Notifying the waiting thread");
                lock.notify(); // notify the waiting thread
            }
        });

        Thread notifyThread2 = new Thread(() -> {
            try {
                Thread.sleep(6000); // sleep for 2 seconds
            } catch (InterruptedException e) {
                System.out.println(e);
            }
            synchronized (lock) {
                System.out.println(LocalTime.now() +  " " + Thread.currentThread().getName()   + " NotifyThread: Notifying the waiting thread");
                lock.notify(); // notify the waiting thread
            }
        });

        waitThread1.start();

        waitThread2.start();

        notifyThread1.start();

        notifyThread2.start();
    }
}

输出结果

11:31:15.969 Thread-0 WaitThread: Going to wait
11:31:15.969 Thread-1 WaitThread: Going to wait
11:31:19.946 Thread-2 NotifyThread: Notifying the waiting thread
11:31:19.946 Thread-0 WaitThread: Woke up
11:31:21.945 Thread-3 NotifyThread: Notifying the waiting thread
11:31:21.945 Thread-1 WaitThread: Woke up

Process finished with exit code 0