package com.cppdy;

class MyThreadA extends Thread{

    MyThreadB b;

    public MyThreadA(MyThreadB b) {

        this.b=b;

    }

    @Override

    public void run() {

        try {

            b.join();

            sleep(1000);

        } catch (Exception e) {

        }

        System.out.println("A子线程执行");

    }

}

class MyThreadB extends Thread{

    @Override

    public void run() {

        try {

            sleep(1000);

        } catch (Exception e) {

        }

        System.out.println("B子线程执行");

    }

}

public class ThreadDemo4 {

    public static void main(String[] args) throws Exception{

        MyThreadB mt2 = new MyThreadB();

        MyThreadA mt1 = new MyThreadA(mt2);

        mt1.start();

        mt2.start();

        mt1.join();

        System.out.println("主线程执行");

    }

}