/*** 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 upProcess finished with exit code 0