/** *  * @描述: 同步工具 * 表示大家彼此等待，大家集合好后才开始出发，分散活动后又在指点地点集合碰合 . * @作者: Wnj . * @创建时间: 2017年5月16日 . * @版本: 1.0 . */public class CyclicBarrierTest {        public static void main(String[] args) {        ExecutorService service = Executors.newCachedThreadPool();        //要有三个线程到了才走        final CyclicBarrier cb = new CyclicBarrier(3);        for (int i = 0; i < 3; i++) {            Runnable runnable = new Runnable() {                public void run() {                    try {                        Thread.sleep((long)(Math.random() * 10000));                                                                        System.out.println("线程" + Thread.currentThread().getName() + "即将到达集合地点1，当前已有"                         + (cb.getNumberWaiting() + 1) + "个已经到达，" + (cb.getNumberWaiting() == 2 ? "都到齐了，继续走啊" : "正在等候"));                        //三个线程的第N个线程等待                        cb.await();                                                Thread.sleep((long)(Math.random() * 10000));                        System.out.println("线程" + Thread.currentThread().getName() + "即将到达集合地点2，当前已有"                         + (cb.getNumberWaiting() + 1)                            + "个已经到达，" + (cb.getNumberWaiting() == 2 ? "都到齐了，继续走啊" : "正在等候"));                                                //三个线程的第N个线程等待                        cb.await();                        Thread.sleep((long)(Math.random() * 10000));                        System.out.println("线程" + Thread.currentThread().getName() + "即将到达集合地点3，当前已有"                        + (cb.getNumberWaiting() + 1)                            + "个已经到达，" + (cb.getNumberWaiting() == 2 ? "都到齐了，继续走啊" : "正在等候"));                                                //三个线程的第N个线程等待                        cb.await();                    }                    catch (Exception e) {                        e.printStackTrace();                    }                }            };            service.execute(runnable);        }        service.shutdown();    }}