Throttling method calls using Guava RateLimiter class

Question

I am trying to throttle the number of calls to a method per second. I tried to achieve this using Guava RateLimiter.

RateLimiter rateLimiter = RateLimiter.create(1.0);//Max 1 call per sec
rateLimiter.acquire();
performOperation();//The method whose calls are to be throttled.

However the methods to the call are not limited to 1 per second but are continuous.

The throttling can be achieved using Thread.sleep() but i wish to use Guava rather that sleep().

I would like to know the right way to achieve the method call trottling using Guava RateLimiter. I have checked the documentation for RateLimiter and tried to use the same but could not achieve the desired result.

Answer 1

You need to call acquire() on the same RateLimiter in every invocation, e.g. by making it available in performOperation():

public class RateLimiterTest {
    public static void main(String[] args) {
        RateLimiter limiter = RateLimiter.create(1.0);
        for (int i = 0; i < 10; i++) {
            performOperation(limiter);
        }
    }

    private static void performOperation(RateLimiter limiter) {
        limiter.acquire();
        System.out.println(new Date() + ": Beep");
    }
}

results in

Fri Aug 07 19:00:10 BST 2015: Beep
Fri Aug 07 19:00:11 BST 2015: Beep
Fri Aug 07 19:00:12 BST 2015: Beep
Fri Aug 07 19:00:13 BST 2015: Beep
Fri Aug 07 19:00:14 BST 2015: Beep
Fri Aug 07 19:00:15 BST 2015: Beep
Fri Aug 07 19:00:16 BST 2015: Beep
Fri Aug 07 19:00:17 BST 2015: Beep
Fri Aug 07 19:00:18 BST 2015: Beep
Fri Aug 07 19:00:19 BST 2015: Beep