谷歌guava包里提供了内存限流工具RateLimiter

示例：

    // 创建一个限流器，该配置可以每秒均匀产生4个令牌
    RateLimiter rateLimiter = RateLimiter.create(4);

    @Test
    public void flowLimitTest() throws InterruptedException {
        List<Thread> threads = new ArrayList<>();
        // 生成10个线程运行
        for(int i = 0 ; i < 10 ; i ++){
            threads.add(new Thread(() -> {
                for(;;){
                    // 抢1个令牌，抢不到阻塞
                    rateLimiter.acquire();
                    System.out.println(Thread.currentThread().getName() + " - " + System.currentTimeMillis());
                }
            }));
            threads.get(i).start();
        }
        threads.get(0).join();
    }

运行结果

Thread-10 - 1588868393118
Thread-9 - 1588868393369
Thread-8 - 1588868393618
Thread-7 - 1588868393868
Thread-6 - 1588868394118
Thread-4 - 1588868394368
Thread-5 - 1588868394619
Thread-3 - 1588868394869
Thread-2 - 1588868395119
Thread-1 - 1588868395369
Thread-10 - 1588868395619
Thread-9 - 1588868395869
Thread-8 - 1588868396119
Thread-7 - 1588868396368
Thread-6 - 1588868396619
Thread-4 - 1588868396869
Thread-5 - 1588868397120
Thread-3 - 1588868397370
Thread-2 - 1588868397620
Thread-1 - 1588868397869