闭锁CountDownLatch

@Test
    public void test02() throws InterruptedException{
        CountDownLatch cdl = new CountDownLatch(2);  //new出CountDownLatch对象，初始指定线程数为2      

        new Thread(new BuyPot(cdl)).run();
        new Thread(new BuyVege(cdl)).run();  //本次测试，只有两个线程都完成才能进行下一步

        cdl.await();   //等待countDown为0时执行
        System.out.println("cook dinner");

    }

class BuyPot implements Runnable{
    CountDownLatch cdl ;

    public BuyPot(CountDownLatch cdl) {
        this.cdl = cdl;
    }

    @Override
    public void run() {
        System.out.println("买锅");        
        cdl.countDown();    //买锅完成后countDown一次
    }
}
class BuyVege implements Runnable{
    CountDownLatch cdl ;

    public BuyVege(CountDownLatch cdl) {
        this.cdl = cdl;
    }

    @Override
    public void run() {

        System.out.println("买菜");        
        cdl.countDown();   //买菜完成后countDown一次
    }
}

买锅
买菜
cook dinner