多线程-使用CountDownLatch达到join的效果

public class ThreadTest {

private static final CountDownLatch ctl = new CountDownLatch(10);
public static void main(String[] args) throws Exception{
System.out.println("主线程执行前："+Thread.currentThread().getName());
test();
ctl.await(2, TimeUnit.SECONDS);//主线程最多等待2秒，不管子线程有没执行完（达到join的效果，阻塞）

System.out.println("主线程执行后："+Thread.currentThread().getName());
}

static void test(){
try{
for(int i=1;i<=10;i++){
//Thread.sleep(1000);
new Thread(){
public void run(){
try {
Thread.sleep(1200);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("子线程正在执行："+Thread.currentThread().getName());
ctl.countDown();
}
}.start();
}
}catch(Exception e){
e.printStackTrace();
}
}
}