notify() notifyAll() 区别

notify

• 参考：https://blog.youkuaiyun.com/weixin_44121696/article/details/109306019

public class ObjectTest {
    public static void main(String[] args) {
        Object objectLock = new Object();
        new Thread(() -> {
            synchronized (objectLock) {
                System.out.println(Thread.currentThread().getName() + "--- hello t1");
                try {
                    objectLock.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println(Thread.currentThread().getName() + "--- t1 被唤醒");

            }
        }, "t1").start();
        new Thread(() -> {
            synchronized (objectLock) {
                System.out.println(Thread.currentThread().getName() + "--- hello t2");
                try {
                    objectLock.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println(Thread.currentThread().getName() + "--- t2 被唤醒");

            }
        }, "t2").start();
        new Thread(() -> {
            synchronized (objectLock) {
                System.out.println(Thread.currentThread().getName() + "--- hello t3");
                try {
                    objectLock.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println(Thread.currentThread().getName() + "---  t3 被唤醒");

            }
        }, "t3").start();
        new Thread(() -> {
            synchronized (objectLock) {
                System.out.println(Thread.currentThread().getName() + "--- hello t4");
                try {
                    objectLock.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println(Thread.currentThread().getName() + "--- t4 被唤醒");

            }
        }, "t4").start();


        new Thread(() -> {
            synchronized (objectLock) {
                objectLock.notify();
                System.out.println(Thread.currentThread().getName() + "--- 唤醒别人");
            }
        }, "t5").start();
    }
}

notifyAll()

public class ObjectTest {
    public static void main(String[] args) {
        Object objectLock = new Object();
        new Thread(() -> {
            synchronized (objectLock) {
                System.out.println(Thread.currentThread().getName() + "--- hello t1");
                try {
                    objectLock.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println(Thread.currentThread().getName() + "--- t1 被唤醒");

            }
        }, "t1").start();
        new Thread(() -> {
            synchronized (objectLock) {
                System.out.println(Thread.currentThread().getName() + "--- hello t2");
                try {
                    objectLock.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println(Thread.currentThread().getName() + "--- t2 被唤醒");

            }
        }, "t2").start();
        new Thread(() -> {
            synchronized (objectLock) {
                System.out.println(Thread.currentThread().getName() + "--- hello t3");
                try {
                    objectLock.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println(Thread.currentThread().getName() + "---  t3 被唤醒");

            }
        }, "t3").start();
        new Thread(() -> {
            synchronized (objectLock) {
                System.out.println(Thread.currentThread().getName() + "--- hello t4");
                try {
                    objectLock.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println(Thread.currentThread().getName() + "--- t4 被唤醒");

            }
        }, "t4").start();


        new Thread(() -> {
            synchronized (objectLock) {
                objectLock.notifyAll();
                System.out.println(Thread.currentThread().getName() + "--- 唤醒别人");
            }
        }, "t5").start();
    }
}