public class TestService {
public static void main(String[] args) {
CountDownLatch countDownLatch = new CountDownLatch(50);
//开启一个线程池
ExecutorService executor = Executors.newCachedThreadPool();
//执行TestThread里面的run方法
executor.execute(new TestThread(countDownLatch));
executor.execute(new TestThread(countDownLatch));
executor.execute(new TestThread(countDownLatch));
//线程池不再接受新的任务
executor.shutdown();
}
}
-
executor.execute(new TestThread(countDownLatch));这段传入的是一个实现Runnable接口的类，执行的方法则是run方法里面的内容，每一个execute则是开启一个线程
public class TestThread implements Runnable{
private CountDownLatch countDownLatch;
public TestThread( CountDownLatch countDownLatch ){
this.countDownLatch = countDownLatch;
}
public void run() {
while (countDownLatch.getCount() >0){
countDownLatch.countDown();
System.out.println("输出："+Thread.currentThread()+">>>"+ countDownLatch.getCount());
}
}
}
-
CountDownLatch countDownLatch = new CountDownLatch(50);这段是启用一个线程辅助类，传入的参数是一个int类型的计数，在TestThread中的run方法中，每执行一次，通过调用countDownLatch.countDown();方法计数减一，当计数内容为0时，则子线程全部执行完成，此时主线程才能继续往下执行。
输出结果
输出：Thread[pool-1-thread-1,5,main]>>>49
输出：Thread[pool-1-thread-1,5,main]>>>47
输出：Thread[pool-1-thread-1,5,main]>>>46
输出：Thread[pool-1-thread-1,5,main]>>>45
输出：Thread[pool-1-thread-1,5,main]>>>44
输出：Thread[pool-1-thread-1,5,main]>>>43
输出：Thread[pool-1-thread-1,5,main]>>>42
输出：Thread[pool-1-thread-1,5,main]>>>41
输出：Thread[pool-1-thread-1,5,main]>>>40
输出：Thread[pool-1-thread-2,5,main]>>>48
输出：Thread[pool-1-thread-1,5,main]>>>39
输出：Thread[pool-1-thread-2,5,main]>>>38
输出：Thread[pool-1-thread-3,5,main]>>>36
输出：Thread[pool-1-thread-1,5,main]>>>36
输出：Thread[pool-1-thread-3,5,main]>>>34
...
具体用法请google
