java 线程方法 ---- join()

class MyThread2 implements Runnable{
 
    @Override
    public void run() {
        for (int i = 0; i < 5; i++){
            System.out.println(Thread.currentThread().getName() + ": " +i);
        }
    }
}
public class Test2 {
    /**
     * t1, t2, 主线程 三个线程顺序执行
     */
    public static void main(String[] args) throws InterruptedException {
        MyThread2 myThread2 = new MyThread2();
        Thread t1 = new Thread(myThread2, "线程A");
        Thread t2 = new Thread(myThread2, "线程B");
 
        t1.start();
        t1.join();
 
        t2.start();
        t2.join();
 
        System.out.println("主线程...");
    }
 
    /**
     * t1, t2 并行执行, 等 t1, t2 都执行完毕再执行主线程
     */
    public void test2() throws InterruptedException {
        MyThread2 myThread2 = new MyThread2();
        Thread t1 = new Thread(myThread2, "线程A");
        Thread t2 = new Thread(myThread2, "线程B");
 
        t1.start();
        t2.start();
 
        t1.join();
        t2.join();
 
        System.out.println("主线程...");
    }
}