java - 为什么线程对象的wait方法不需要notify方法来唤醒？

Question

当我在线程对象上调用 wait() 方法时，等待线程将在同步线程完成运行时被唤醒，为什么线程对象的行为与使用 wait() 的普通对象不同？

Thread thread1 = new Thread(()-> {
            System.out.println("thread 1 start");
            try {
            Thread.sleep(3000);
            System.out.println("thread over");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }});
thread1.start();

synchronized (thread1) {
            try {
                thread1.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        System.out.println("main thread wake up");

我预计主线程在 3 秒后不会唤醒，但事实并非如此。

Answer 1

The javadoc说:

As a thread terminates the this.notifyAll method is invoked. It is recommended that applications not use wait, notify, or notifyAll on Thread instances.