1.应用场景

CyclicBarrier应用于多个线程必须同时开始

2.代码

    private static CyclicBarrier cyclicBarrier = new CyclicBarrier(5);
    public static void main(String[] args) {
        ExecutorService executorService = Executors.newCachedThreadPool();
        for (int i = 0; i < 5; i++) {
            final int index = i;
            try{
                Thread.sleep(1000);
            }catch (InterruptedException e){
                e.printStackTrace();
            }
            executorService.execute(new Runnable() {
                @Override
                public void run() { 
                    go();
                }
            });
        }
        executorService.shutdown();
    }

    private static void go() {
        System.out.println(Thread.currentThread().getName()+"准备就绪");
        try {
            cyclicBarrier.await();
            System.out.println(Thread.currentThread().getName()+"开始执行");
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (BrokenBarrierException e) {
            e.printStackTrace();
        }
    }