Bucket4j use case

  bucket4j

Order

This article mainly demonstrates several examples of bucket4j

maven

        <dependency>
            <groupId>com.github.vladimir-bukhtoyarov</groupId>
            <artifactId>bucket4j-core</artifactId>
            <version>4.0.1</version>
        </dependency>

rate limit

    @Test
    public void testRateLimit(){
        // define the limit 1 time per 10 minute
        Bandwidth limit = Bandwidth.simple(1, Duration.ofMinutes(10));
        // construct the bucket
        Bucket bucket = Bucket4j.builder().addLimit(limit).build();
        IntStream.rangeClosed(1,5)
                .forEach(i -> {
                    executor.submit(() -> {
                        if(bucket.tryConsume(1)){
                            LOGGER.info("acquired");
                        }else{
                            LOGGER.info("blocked");
                        }
                    });
                });
    }
  • Here, the simple method is used to construct Bandwidth, and then the bucket instance is constructed.

scheduler

    @Test
    public void testAsScheduler(){
        // define the limit 100 times per 1 minute
        Bandwidth limit = Bandwidth.simple(5, Duration.ofMinutes(1));
        // construct the bucket
        Bucket bucket = Bucket4j.builder().addLimit(limit).build();

        // do polling in infinite loop
        while (true) {
            // Consume a token from the token bucket.
            // If a token is not available this method will block until the refill adds one to the bucket.
            try {
                bucket.asScheduler().consume(1);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            LOGGER.info("do remote call");
        }
    }

Output instance

23:14:46.740 [main] INFO com.example.demo.Bucket4jTest - do remote call
23:14:46.744 [main] INFO com.example.demo.Bucket4jTest - do remote call
23:14:46.744 [main] INFO com.example.demo.Bucket4jTest - do remote call
23:14:46.744 [main] INFO com.example.demo.Bucket4jTest - do remote call
23:14:46.744 [main] INFO com.example.demo.Bucket4jTest - do remote call
23:14:58.749 [main] INFO com.example.demo.Bucket4jTest - do remote call
23:15:10.749 [main] INFO com.example.demo.Bucket4jTest - do remote call
23:15:22.754 [main] INFO com.example.demo.Bucket4jTest - do remote call
23:15:34.757 [main] INFO com.example.demo.Bucket4jTest - do remote call
23:15:46.759 [main] INFO com.example.demo.Bucket4jTest - do remote call
23:15:58.762 [main] INFO com.example.demo.Bucket4jTest - do remote call
23:16:10.765 [main] INFO com.example.demo.Bucket4jTest - do remote call
  • After the first five tokens are consumed, one token is consumed every 12 seconds thereafter.

Summary

Bucket4j class library is an excellent java current limiting class library, which can be used for current limiting or simple scheduling.

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