Java中JUC包(java.util.concurrent)下的常用子类

addAndGet(int delta);   i += delta;
decrementAndGet(); --i;
getAndDecrement(); i--;
incrementAndGet(); ++i;
getAndIncrement(); i++;

public static void main(String[] args) {
        // 在构造参数传入可用资源的个数
        // 可用资源为6个
        Semaphore semaphore = new Semaphore(6);
        Runnable runnable = new Runnable() {
            @Override
            public void run() {
                try {
                    System.out.println(Thread.currentThread().getName() + "准备申请资源");
                    // P操作,每次申请两个资源
                    semaphore.acquire(2);
                    System.out.println(Thread.currentThread().getName() + "获取资源成功");
                    Thread.sleep(1000);
                    System.out.println(Thread.currentThread().getName() + "释放资源");
                    // V操作，默认释放一个占有的资源
                    semaphore.release(2);
                }catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        };
        for (int i = 0; i < 20; i++) {
            Thread t = new Thread(runnable,String.valueOf(i + 1));
            t.start();
        }
    }

public static void main(String[] args) throws InterruptedException {
        // 等待线程需要等待的线程数，必须等这10个子线程全部执行完毕再恢复执行
        CountDownLatch latch = new CountDownLatch(10);
        Runnable runnable = new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(new Random().nextInt(1000));
                    System.out.println(Thread.currentThread().getName() + "到达终点");
                    // 计数器 - 1
                    latch.countDown();
                }catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        };
        for (int i = 0; i < 10; i++) {
            Thread t = new Thread(runnable,"运动员" + i + 1);
            t.start();
        }
        // main线程就是裁判线程，需要等待所有运动员到底终点再恢复执行
        // 直到所有线程调用countdown方法将计数器减为0继续执行
        latch.await();
        System.out.println("比赛结束~最终获胜的是鹏哥，有请冠军给大家高歌一首~");
    }