限流实现-小工具

需求描述

写一个1秒两个的限流工具类，2r/s


public class LimitHelper {

    private int maxLimit;

    private Semaphore semaphore;

    private int timeoutSeconds;

    public LimitHelper(int maxLimit, int timeoutSeconds) {
        this.maxLimit = maxLimit;
        semaphore = new Semaphore(maxLimit);
        this.timeoutSeconds = timeoutSeconds;
        this.autoRelease();
    }

    /**
     * 每秒钟释放两个信号出来
     */
    private void autoRelease() {
        new Thread(() -> {
            try {
                while (true) {
                    TimeUnit.SECONDS.sleep(timeoutSeconds);
                    if (!semaphore.tryAcquire(1)) {
                        // 无信号了
                        semaphore.release(maxLimit);
                    }else {
                        // 池中有信号，并且消耗了一个，释放一个补偿
                        semaphore.release(1);
                    }
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }).start();
    }

    public boolean acquire() {
        try {
            return semaphore.tryAcquire(1, timeoutSeconds, TimeUnit.SECONDS);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
    }

    public static void main(String[] args) {
        LimitHelper limitHelper = new LimitHelper(2, 1);
        for (int i = 0; i < 5; i++) {
            new Thread(() -> {
                while (true) {
                    if (limitHelper.acquire()) {
                        System.out.println( System.currentTimeMillis() / 1000+ "  " + Thread.currentThread().getName() + " 获取到令牌");
                        try {
                            // 业务处理
                            TimeUnit.MILLISECONDS.sleep(20);
                        } catch (InterruptedException e) {
                            throw new RuntimeException(e);
                        }
                    } else {
                        System.out.println(System.currentTimeMillis() / 1000 + "  "+Thread.currentThread().getName() + " 被限流了");
                    }
                }
            }).start();
        }
    }

}