CountDownLatch 、CyclicBarrier、Semaphore 使用

Semaphore 使用

public class SemaphoreDemo {
    public static void main(String[] args) {
        /**
         * 多线程同时抢多个资源
         * permits=1时，相当于锁
         *
         */
        Semaphore semaphore = new Semaphore(2);
        for (int i = 0; i < 10; i++) {
            new Thread(() -> {
                try {
                    // 表示线程抢到了资源
                    semaphore.acquire();
                    System.out.println("线程" + Thread.currentThread().getName() + "抢到了车位");
                    TimeUnit.SECONDS.sleep(1);
                    System.out.println("线程" + Thread.currentThread().getName() + "离开了车位");
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } finally {
                    // 资源释放
                    semaphore.release();
                }
            }, String.valueOf(i)).start();

        }
    }
}

CountDownLatch使用

public class CountDownLatchDemo {
    public static void main(String[] args) {

        CountDownLatch countDownLatch = new CountDownLatch(6);

        for (int i = 1; i <= 6; i++) {
            new Thread(() -> {
                System.out.println(Thread.currentThread().getName() + "被灭！");
                countDownLatch.countDown();
            }, Country.getByCode(i)).start();
        }
        try {
            countDownLatch.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("秦国统一六国~~~");
    }
}

enum Country {

    ZHAO(1, "赵国"),
    WEI(2, "魏国"),
    HAN(3, "韩国"),
    QI(4, "齐国"),
    CHU(5, "楚国"),
    YAN(6, "燕国");

    @Getter
    private Integer code;
    @Getter
    private String name;

    Country(Integer code, String name) {
        this.code = code;
        this.name = name;
    }

    public static String getByCode(Integer code) {
        return Arrays.asList(Country.values()).stream()
            .filter(o -> o.getCode() == code).findFirst()
            .map(Country::getName).get();
    }
}

CyclicBarrier 使用

public static void main(String[] args) {
        CyclicBarrier cyclicBarrier = new CyclicBarrier(7);
        for (int i = 1; i <= 7; i++) {
            int finalI = i;
            new Thread(() -> {
                try {
                    System.out.println("集齐第" + finalI + "颗龙珠");
                    cyclicBarrier.await();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } catch (BrokenBarrierException e) {
                    e.printStackTrace();
                }
            }, String.valueOf(i)).start();
        }
        System.out.println("召唤神龙");
    }