关于Java的join方法

[woxiaomaa]

package com.ma.third.join;

public class Thread1 extends Thread {

	@Override
	public void run() {
		super.run();
		synchronized(this){
		try {
				System.out.println("t1 begin");
				Thread.sleep(5000);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			System.out.println("t1 end");
		}
	}

	
}

package com.ma.third.join;

public class MyMain1 {
	public static void main(String[] args) {
		Thread1 t1 = new Thread1();
		t1.setName("t1");
		t1.start();
		try {
			t1.join(500);
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		System.out.println("main end");
		
	}

}

请问大佬们：join方法是通过wait方法实现的，那么调用谁的wait？是t1线程的wait还是主线程的wait？如果是调用t1线程的wait，那么程序有时如何notify主线程的

[weixin_39670158]

join方法点进去 执行如下代码 while (isAlive()) {/Tests if this thread is alive. A thread is alive if it has been started and has not yet died. wait(0); } 大胆猜测:wait(0)大概意思是 0毫秒后该线程开始执行，配合while语句 相当于让执行join方法的线程一直跑直到(isAlive())为false