CyclicBarrier

 

lCyclicBarrier

表示大家彼此等待，大家集合好后才开始出发，分散活动后又在指定地点集合碰面，这就好比整个公司的人员利用周末时间集体郊游一样，先各自从家出发到公司集合后，再同时出发到公园游玩，在指定地点集合后再同时开始就餐，…。

 

public static void main(String[] args) {
  ExecutorService service = Executors.newCachedThreadPool();
  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"));      
      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"));
      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"));      
      cb.await();      
     } catch (Exception e) {
      e.printStackTrace();
     }    
    }
   };
   service.execute(runnable);
  }
  service.shutdown();
 }