java并发编程之同步器代码示例

package hb.java.thread;import java.util.concurrent.CountDownLatch;public class CountDownLatchTest {private static final int THREAD_COUNT = 10;// 在调用startSingal.countDown()之前调用了startSingal.await()的线程一律等待，直到startSingal.countDown()的调用private static final CountDownLatch startSingal = new CountDownLatch(1);// 在finishedSingal的初始化记数量通过调用finishedSingal.countDown()减少为0时调用了finishedSingal.await()的线程一直阻塞private static final CountDownLatch finishedSingal = new CountDownLatch(THREAD_COUNT);public static void main(String[] args) throws InterruptedException {for (int i = 0; i < THREAD_COUNT; i++) {new Thread("Task " + i) {public void run() {System.out.println(Thread.currentThread().getName()+ " prepared!!");try {startSingal.await();}catch (InterruptedException e) {e.printStackTrace();}System.out.println(Thread.currentThread().getName()+ " finished!!");finishedSingal.countDown();};}.start();}Thread.sleep(1000);startSingal.countDown();// 所有的线程被唤醒，同时开始工作.countDown 方法的线程等到计数到达零时才继续finishedSingal.await();// 等待所有的线程完成!!System.out.println("All task are finished!!");}}