【流控】Google Guava RateLimiter 本地限流组件

官方Test样例：https://github.com/google/guava/blob/master/guava-tests/test/com/google/common/util/concurrent/RateLimiterTest.java

Maven依赖

<dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>20.0</version>
        </dependency>

核心方法

 RateLimiter.create(2）

 RateLimiter.acquire())

Demo: 基础入门

public class Application2 {
    public static void main(String[] args) {
        // create方法参数permitsPerSecond
        RateLimiter rateLimiter = RateLimiter.create(2);
        System.out.println(rateLimiter.toString());
        List<Runnable> tasks = new ArrayList<Runnable>();
        for (int i = 0; i < 10; i++) {
            tasks.add(new UserRequest(i));
        }
        ExecutorService threadPool = Executors.newCachedThreadPool();
        for (Runnable runnable : tasks) {
            System.out.println("等待时间：" + rateLimiter.acquire());
            threadPool.execute(runnable);
        }
    }

    private static class UserRequest implements Runnable {
        private int id;

        public UserRequest(int id) {
            this.id = id;
        }

        public void run() {
            System.out.println(id);
        }
    }

}

执行效果

RateLimiter[stableRate=2.0qps]
等待时间：0.0
0
等待时间：0.485271
1
等待时间：0.498734
2
等待时间：0.499003
3
等待时间：0.499248
4
等待时间：0.499308
5
等待时间：0.49971
6
等待时间：0.49874
7
等待时间：0.499551
8
等待时间：0.495876
9