Bucket4j 8.10.1 Reference

Bucket bucket = Bucket.builder()
   .addLimit(...)
   .build();

BucketConfiguration configuration = BucketConfiguration.builder()
    .addLimit(...)
    .build()

Bucket bucket = Bucket.builder()
    .addLimit(limit -> limit.capacity(42))
    .build()

Bucket bucket = Bucket.builder()
    .addLimit(limit -> limit.capacity(...).refillXXX(...)) // where XXX - is concrete refill style
    .build()

Bucket bucket = Bucket.builder()
    .addLimit(...)
    .withNanosecondPrecision()
    .withSynchronizationStrategy(SynchronizationStrategy.LOCK_FREE)
    .build()

<dependency>
    <groupId>com.bucket4j</groupId>
    <artifactId>bucket4j-core</artifactId>
    <version>8.10.1</version>
</dependency>

implementation 'com.bucket4j:bucket4j-core:8.10.1'

import io.github.bucket4j.Bucket;

public class ThrottlingFilter implements javax.servlet.Filter {

    private Bucket createNewBucket() {
         return Bucket.builder()
            .addLimit(limit -> limit.capacity(50).refillGreedy(10, Duration.ofSeconds(1)))
            .build();
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;
        HttpSession session = httpRequest.getSession(true);

        String appKey = SecurityUtils.getThirdPartyAppKey();
        Bucket bucket = (Bucket) session.getAttribute("throttler-" + appKey);
        if (bucket == null) {
            bucket = createNewBucket();
            session.setAttribute("throttler-" + appKey, bucket);
        }

        // tryConsume returns false immediately if no tokens available with the bucket
        if (bucket.tryConsume(1)) {
            // the limit is not exceeded
            filterChain.doFilter(servletRequest, servletResponse);
        } else {
            // limit is exceeded
            HttpServletResponse httpResponse = (HttpServletResponse) servletResponse;
            httpResponse.setContentType("text/plain");
            httpResponse.setStatus(429);
            httpResponse.getWriter().append("Too many requests");
        }
    }

}

        HttpServletResponse httpResponse = (HttpServletResponse) servletResponse;
        ConsumptionProbe probe = bucket.tryConsumeAndReturnRemaining(1);
        if (probe.isConsumed()) {
            // the limit is not exceeded
            httpResponse.setHeader("X-Rate-Limit-Remaining", "" + probe.getRemainingTokens());
            filterChain.doFilter(servletRequest, servletResponse);
        } else {
            // limit is exceeded
            HttpServletResponse httpResponse = (HttpServletResponse) servletResponse;
            httpResponse.setStatus(429);
            httpResponse.setHeader("X-Rate-Limit-Retry-After-Seconds", "" + TimeUnit.NANOSECONDS.toSeconds(probe.getNanosToWaitForRefill()));
            httpResponse.setContentType("text/plain");
            httpResponse.getWriter().append("Too many requests");
        }

int initialTokens = 42;
Bucket bucket = Bucket.builder()
    .addLimit(limit -> limit.capacity(1000).refillGreedy(1000, ofHours(1)).initialTokens(initialTokens))
    .build();

Bucket wallet;
...
if (wallet.tryConsume(50)) { // get 50 cents from wallet
    try {
        buyCocaCola();
    } catch(NoCocaColaException e) {
        // return money to wallet
        wallet.addTokens(50);
    }
}

Bucket.builder().withNanosecondPrecision()

public class ClusteredTimeMeter implements TimeMeter {

    @Override
    public long currentTimeNanos() {
        return ClusteredClock.currentTimeMillis() * 1_000_000;
    }

}

Bucket bucket = Bucket.builder()
    .withCustomTimePrecision(new ClusteredTimeMeter())
    .addLimit(limit -> limit.capacity(100).refillGreedy(100, ofMinutes(1)))
    .build();

// define the bucket with capacity 100  and refill 100 tokens per 1 minute
Bucket bucket = Bucket.builder()
    .addLimit(limit -> limit.capacity(100).refillGreedy(100, ofMinutes(1)))
    .build();

// do polling in infinite loop
while (true) {
    List<Message> messages = consumer.poll();
    for (Message message : messages) {
        // 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.
        bucket.asBlocking().consume(1);
        process(message);
    }
}

BucketListener listener = new MyListener();

Bucket bucket = Bucket.builder()
    .addLimit(limit -> limit,capacity(100).refillGreedy(100, ofMinutes(1)))
    .build()
    .toListenable(listener);

public static Bucket decorateBucketByStatListener(Bucket originalBucket, String bucketName, MetricRegistry registry) {
  SimpleBucketListener stat = new SimpleBucketListener();
  registry.register(name + ".consumed", (Gauge<Long>) stat::getConsumed);
  registry.register(name + ".rejected", (Gauge<Long>) stat::getRejected);
  registry.register(name + ".parkedNanos", (Gauge<Long>) stat::getParkedNanos);
  registry.register(name + ".interrupted", (Gauge<Long>) stat::getInterrupted);
  registry.register(name + ".delayedNanos", (Gauge<Long>) stat::getDelayedNanos);

  return originalBucket.toListenable(stat);
}

// for io.github.bucket4j.Bucket
Bucket bucket = ...;
bucket.asVerbose();

// for io.github.bucket4j.Bucket
Bucket bucket = ...;
VerboseBucket verboseBucket = bucket.asVerbose();

// for io.github.bucket4j.distributed.BucketProxy
BucketProxy bucket = ...;
VerboseBucket verboseBucket = bucket.asVerbose();

// for io.github.bucket4j.distributed.AsyncBucketProxy
AsyncBucketProxy bucket = ...;
AsyncVerboseBucket verboseBucket = bucket.asVerbose();

VerboseResult<ConsumptionProbe> verboseResult = bucket.asVerbose().tryConsumeAndReturnRemaining(numberOfTokens);

BucketConfiguration bucketConfiguration = verboseResult.getConfiguration();
long capacity = Arrays.stream(bucketConfiguration.getBandwidths())
                .mapToLong(Bandwidth::getCapacity)
                .max().getAsLong();
response.addHeader("RateLimit-Limit", "" + capacity));

VerboseResult.Diagnostics diagnostics = verboseResult.getDiagnostics()
response.addHeader("RateLimit-Remaining", "" + diagnostics.getAvailableTokens());
response.addHeader("RateLimit-Reset", "" + TimeUnit.NANOSECONDS.toSeconds(diagnostics.calculateFullRefillingTime()));

ConsumptionProbe probe = verboseResult.getValue();
if (probe.isConsumed()) {
    // the limit is not exceeded
    filterChain.doFilter(servletRequest, servletResponse);
} else {
    // limit is exceeded
    HttpServletResponse httpResponse = (HttpServletResponse) servletResponse;
    httpResponse.setStatus(429);
    httpResponse.setContentType("text/plain");
    httpResponse.getWriter().append("Too many requests");
}

    Bucket bucket = Bucket.builder()
         .addLimit(limit -> limit.capacity(10).refillGreedy(10, ofSeconds(1)).id("technical-limit"))
         .addLimit(limit -> limit.capacity(10000).refillGreedy(10000, ofHours(1)).id("business-limit"))
         .build();
     ...
     BucketConfiguration newConfiguration = BucketConfiguration.builder()
         .addLimit(limit -> limit.capacity(100).refillGreedy(100, ofSeconds(10)).id("technical-limit"))
         .addLimit(limit -> limit.capacity(5000).refillGreedy(5000, ofHours(1)).id("business-limit"))
         .build();
     bucket.replaceConfiguration(newConfiguration, TokensInheritanceStrategy.PROPORTIONALLY);

Bucket bucket = Bucket.builder()
    .addLimit(limit -> capacity(10_000).refillGreedy(10_000, ofHours(1)))
    .addLimit(limit -> capacity(20).refillGreedy(20, ofSeconds(1))) // attacker is unable to achieve 1000RPS and crash service in short time

Bandwidth.builder().capacity(100).refillGreedy(2, ofNanos(1));

Bandwidth.builder().capacity(10_000).refillGreedy(1_001, ofNanos(1_000));

Bandwidth.builder().capacity(1_000_000).refillGreedy(1_000_001, ofMillis(1));

Duration.ofNanos(Long.MAX_VALUE);

Bandwidth.builder(limit -> limit.capacity(...).refillGreedy(42, Duration.ofMinutes(153722867280912930));

Exception in thread "main" java.lang.ArithmeticException: long overflow
   at java.lang.Math.multiplyExact(Math.java:892)
   at java.time.Duration.toNanos(Duration.java:1186)
   ...

public class IpThrottlingFilter implements javax.servlet.Filter {

    private static final BucketConfiguration configuration = BucketConfiguration.builder()
          .addLimit(limit -> limit.capacity(30).refillGreedy(30, ofMinutes(1)))
          .build();

    // cache for storing token buckets, where IP is key.
    @Inject
    private javax.cache.Cache<String, byte[]> cache;

    private ProxyManager<String> buckets;

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
         // init bucket registry
         buckets = new JCacheProxyManager<>(cache);
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;
        String ip = IpHelper.getIpFromRequest(httpRequest);

        // acquire cheap proxy to the bucket
        Bucket bucket = proxyManager.builder().build(key, configuration);

        // tryConsume returns false immediately if no tokens available with the bucket
        if (bucket.tryConsume(1)) {
            // the limit is not exceeded
            filterChain.doFilter(servletRequest, servletResponse);
        } else {
            // limit is exceeded
            HttpServletResponse httpResponse = (HttpServletResponse) servletResponse;
            httpResponse.setContentType("text/plain");
            httpResponse.setStatus(429);
            httpResponse.getWriter().append("Too many requests");
        }
    }

}

public class IpThrottlingFilter implements javax.servlet.Filter {

    // service to provide per user limits
    @Inject
    private LimitProvider limitProvider;

    // cache for storing token buckets, where IP is key.
    @Inject
    private javax.cache.Cache<String, byte[]> cache;

    private ProxyManager<String> buckets;

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
         // init bucket registry
         buckets = new JCacheProxyManager<>(cache);
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;
        String userId = AutentificationHelper.getUserIdFromRequest(httpRequest);

        // prepare configuration supplier which will be called(on the first interaction with proxy) if the bucket was not saved yet previously.
        Supplier<BucketConfiguration> configurationLazySupplier = getConfigSupplierForUser(userId);

        // acquire cheap proxy to the bucket
        Bucket bucket = proxyManager.builder().build(key, configurationLazySupplier);

        // tryConsume returns false immediately if no tokens available with the bucket
        if (bucket.tryConsume(1)) {
            // the limit is not exceeded
            filterChain.doFilter(servletRequest, servletResponse);
        } else {
            // limit is exceeded
            HttpServletResponse httpResponse = (HttpServletResponse) servletResponse;
            httpResponse.setContentType("text/plain");
            httpResponse.setStatus(429);
            httpResponse.getWriter().append("Too many requests");
        }
    }

    private Supplier<BucketConfiguration> getConfigSupplierForUser(String userId) {
         return () -> {
             long translationsPerDay = limitProvider.readPerDayLimitFromAgreementsDatabase(userId);
             return BucketConfiguratiion.builder()
                    .addLimit(limit -> limit.capacity(translationsPerDay).refillGreedy(1_000, ofDays(1)))
                     .build();
         };
    }

}

import javax.cache.Cache;
import javax.cache.processor.EntryProcessor;
import java.util.concurrent.CountDownLatch;
import java.io.Serializable;

public class CompatibilityTest {

    final Cache<String, Integer> cache;


    public CompatibilityTest(Cache<String, Integer> cache) {
        this.cache = cache;
    }

    public void test() throws InterruptedException {
        String key = "42";
        int threads = 4;
        int iterations = 1000;
        cache.put(key, 0);
        CountDownLatch latch = new CountDownLatch(threads);
        for (int i = 0; i < threads; i++) {
            new Thread(() -> {
                try {
                    for (int j = 0; j < iterations; j++) {
                        EntryProcessor<String, Integer, Void> processor = (EntryProcessor<String, Integer, Void> & Serializable) (mutableEntry, objects) -> {
                            int value = mutableEntry.getValue();
                            mutableEntry.setValue(value + 1);
                            return null;
                        };
                        cache.invoke(key, processor);
                    }
                } finally {
                    latch.countDown();
                }
            }).start();
        }
        latch.await();
        int value = cache.get(key);
        if (value == threads * iterations) {
            System.out.println("Implementation which you use is compatible with Bucket4j");
        } else {
            String msg = "Implementation which you use is not compatible with Bucket4j";
            msg += ", " + (threads * iterations - value) + " writes are missed";
            throw new IllegalStateException(msg);
        }
    }

}

<dependency>
    <groupId>com.bucket4j</groupId>
    <artifactId>bucket4j-hazelcast</artifactId>
    <version>8.10.1</version>
</dependency>

<dependency>
    <groupId>com.bucket4j</groupId>
    <artifactId>bucket4j-hazelcast-4</artifactId>
    <version>8.10.1</version>
</dependency>

IMap<K, byte[]> map = ...;
private static final HazelcastProxyManager<K> proxyManager = new HazelcastProxyManager(map);

...
BucketConfiguration configuration = BucketConfiguration.builder()
    .addLimit(limit -> limit.capacity(1_000).refillGreedy(1_000, ofMinutes(1)))
    .build();

Bucket bucket = proxyManager.builder().build(key, configuration);

IMap<K, byte[]> map = ...;
Duration evictionJitter = Duration.ofSeconds(15);
expiration = ExpirationAfterWriteStrategy.basedOnTimeForRefillingBucketUpToMax(evictionJitter)

private static final HazelcastProxyManager<K> proxyManager = new HazelcastProxyManager<>(map, ClientSideConfig.getDefault().withExpirationAfterWriteStrategy(expiration)));

import com.hazelcast.config.Config;
import com.hazelcast.config.SerializationConfig;
import com.hazelcast.config.SerializerConfig;
import io.github.bucket4j.grid.hazelcast.serialization.HazelcastSerializer;
...
    Config config = ...
    SerializationConfig serializationConfig = config.getSerializationConfig();

    // the starting type ID number for Bucket4j classes.
    // you free to choose any unused ID, but be aware that Bucket4j uses 2 types currently,
    // and may use more types in the future, so leave enough empty space after baseTypeIdNumber
    int baseTypeIdNumber = 10000;

    HazelcastProxyManager.addCustomSerializers(serializationConfig, baseTypeIdNumber);

# ----- Hazelcast SERIALIZATIONs configuration -----
serialization:
  serializers:
    - type-class: io.github.bucket4j.grid.hazelcast.HazelcastEntryProcessor
      class-name: io.github.bucket4j.grid.hazelcast.serialization.HazelcastEntryProcessorSerializer
    - type-class: io.github.bucket4j.grid.hazelcast.SimpleBackupProcessor
      class-name: io.github.bucket4j.grid.hazelcast.serialization.SimpleBackupProcessorSerializer
    - type-class: io.github.bucket4j.grid.hazelcast.HazelcastOffloadableEntryProcessor
      class-name: io.github.bucket4j.grid.hazelcast.serialization.HazelcastOffloadableEntryProcessorSerializer

<dependency>
    <groupId>com.bucket4j</groupId>
    <artifactId>bucket4j-ignite</artifactId>
    <version>8.10.1</version>
</dependency>

org.apache.ignite.IgniteCache<K, byte[]> cache = ...;
private static final IgniteProxyManager proxyManager = new IgniteProxyManager(cache);
...

BucketConfiguration configuration = BucketConfiguration.builder()
    .addLimit(limit -> limit.capacity(1_000).refillGreedy(1_000, ofMinutes(1)))
    .build();
Bucket bucket = proxyManager.builder().build(key, configuration);

org.apache.ignite.client.ClientCache<K, byte[]> cache = ...;
org.apache.ignite.client.ClientCompute clientCompute = ...;
private static final IgniteThinClientProxyManager<K> proxyManager = new IgniteThinClientProxyManager(cache, clientCompute)
...

BucketConfiguration configuration = BucketConfiguration.builder()
    .addLimit(limit -> limit.capacity(1_000).refillGreedy(1_000, ofMinutes(1)))
    .build();
Bucket bucket = proxyManager.builder().build(key, configuration);

org.apache.ignite.client.ClientCache<K, byte[]> cache = ...;
private static final IgniteThinClientCasBasedProxyManager<K> proxyManager = new IgniteThinClientCasBasedProxyManager(cache)
...

BucketConfiguration configuration = BucketConfiguration.builder()
    .addLimit(limit -> limit.capacity(1_000).refillGreedy(1_000, ofMinutes(1)))
    .build();
Bucket bucket = proxyManager.builder().build(key, configuration);

<dependency>
    <groupId>com.bucket4j</groupId>
    <artifactId>bucket4j-infinispan</artifactId>
    <version>8.10.1</version>
</dependency>

<dependency>
    <groupId>com.bucket4j</groupId>
    <artifactId>bucket4j-infinispan-8</artifactId>
    <version>8.10.1</version>
</dependency>

Jan 02, 2020 4:57:56 PM org.infinispan.marshall.persistence.impl.PersistenceMarshallerImpl objectToBuffer
WARN: ISPN000559: Cannot marshall 'class io.github.bucket4j.grid.infinispan.InfinispanProcessor'
java.lang.IllegalArgumentException: No marshaller registered for Java type io.github.bucket4j.grid.infinispan.SerializableFunctionAdapter
   at org.infinispan.protostream.impl.SerializationContextImpl.getMarshallerDelegate(SerializationContextImpl.java:279)
   at org.infinispan.protostream.WrappedMessage.writeMessage(WrappedMessage.java:240)
   at org.infinispan.protostream.ProtobufUtil.toWrappedStream(ProtobufUtil.java:196)

import io.github.bucket4j.grid.infinispan.serialization.Bucket4jProtobufContextInitializer;
import org.infinispan.configuration.global.GlobalConfigurationBuilder;
...
GlobalConfigurationBuilder builder = new GlobalConfigurationBuilder();
builder.serialization().addContextInitializer(new Bucket4jProtobufContextInitializer());

<serialization>
    <context-initializer class="io.github.bucket4j.grid.infinispan.serialization.Bucket4jProtobufContextInitializer"/>
</serialization>

org.infinispan.functional.FunctionalMap.ReadWriteMap<K, byte[]> map = ...;
private static final InfinispanProxyManager<K> proxyManager = new InfinispanProxyManager(map);

...
BucketConfiguration configuration = BucketConfiguration.builder()
    .addLimit(limit -> limit.capacity(1_000).refillGreedy(1_000, ofMinutes(1)))
    .build(key, configuration);

Bucket bucket = proxyManager.builder().build(configuration);

<dependency>
    <groupId>com.bucket4j</groupId>
    <artifactId>bucket4j-coherence</artifactId>
    <version>8.10.1</version>
</dependency>

com.tangosol.net.NamedCache<K, byte[]> cache = ...;
private static final CoherenceProxyManager<K> proxyManager = new CoherenceProxyManager(map);

...
BucketConfiguration configuration = BucketConfiguration.builder()
    .addLimit(limit -> limit.capacity(1_000).refillGreedy(1_000, ofMinutes(1)))
    .build(key, configuration);

Bucket bucket = proxyManager.builder().build(configuration);

<pof-config xmlns="http://xmlns.oracle.com/coherence/coherence-pof-config"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xsi:schemaLocation="http://xmlns.oracle.com/coherence/coherence-pof-config coherence-pof-config.xsd">

    <user-type-list>
        <!-- Include default Coherence types -->
        <include>coherence-pof-config.xml</include>

        <!-- Define serializers for Bucket4j classes -->
        <user-type>
            <type-id>1001</type-id>
            <class-name>io.github.bucket4j.grid.coherence.CoherenceProcessor</class-name>
            <serializer>
                <class-name>io.github.bucket4j.grid.coherence.pof.CoherenceEntryProcessorPofSerializer</class-name>
            </serializer>
        </user-type>
    </user-type-list>
</pof-config>

<dependency>
    <groupId>com.bucket4j</groupId>
    <artifactId>bucket4j-redis</artifactId>
    <version>8.10.1</version>
</dependency>

org.redisson.command.CommandExecutor commandExecutor = ...;
RedissonBasedProxyManager<String> proxyManager = RedissonBasedProxyManager.builderFor(commandExecutor)
    .withExpirationStrategy(ExpirationAfterWriteStrategy.basedOnTimeForRefillingBucketUpToMax(Duration.ofSeconds(10)))
    .withKeyMapper(Mapper.STRING)
    .build();
...

BucketConfiguration configuration = BucketConfiguration.builder()
    .addLimit(limit -> capacity(1_000).refillGreedy(1_000, ofMinutes(1)))
    .build();
Bucket bucket = proxyManager.builder().build(key, configuration);

io.lettuce.core.RedisClient redisClient = ...;
StatefulRedisConnection<String, byte[]> redisConnection = redisClient.connect(RedisCodec.of(StringCodec.UTF8, ByteArrayCodec.INSTANCE));
LettuceBasedProxyManager<String> proxyManager = LettuceBasedProxyManager.builderFor(redisConnection)
    .withExpirationStrategy(ExpirationAfterWriteStrategy.basedOnTimeForRefillingBucketUpToMax(ofSeconds(10)))
    .build();
...

BucketConfiguration configuration = BucketConfiguration.builder()
    .addLimit(limit -> capacity(1_000).refillGreedy(1_000, ofMinutes(1)))
    .build();
Bucket bucket = proxyManager.builder().build(key, configuration);

redis.clients.jedis.JedisPool jedisPool = ...;
JedisBasedProxyManager<String> proxyManager = JedisBasedProxyManager.builderFor(jedisPool)
    .withExpirationStrategy(ExpirationAfterWriteStrategy.basedOnTimeForRefillingBucketUpToMax(ofSeconds(10)))
    .withKeyMapper(Mapper.STRING)
    .build();
...

BucketConfiguration configuration = BucketConfiguration.builder()
    .addLimit(limit -> capacity(1_000).refillGreedy(1_000, ofMinutes(1)))
    .build();
Bucket bucket = proxyManager.builder().build(key, configuration);

    SQLProxyConfiguration configuration = SQLProxyConfiguration.builder()
        .withTableSettings(tableSettings)
        .build(dataSource);
    proxyManager = new MSSQLSelectForUpdateBasedProxyManager<>(configuration);

public class SmsServlet extends javax.servlet.http.HttpServlet {

    private SmsSender smsSender;
    private AsyncProxyManager<String> buckets;
    private Supplier<BucketConfiguration> configuration;

    @Override
    public void init(ServletConfig config) throws ServletException {
        super.init(config);
        ServletContext ctx = config.getServletContext();

        smsSender = (SmsSender) ctx.getAttribute("sms-sender");

        FunctionalMapImpl<String, byte[]> bucketMap = (FunctionalMapImpl<String, byte[]>) ctx.getAttribute("bucket-map");
        this.buckets = new InfinispanProxyManager(bucketMap).asAsync();

        this.configuration = () -> {
            return BucketConfiguratiion.builder()
                .addLimit(limit -> limit.capacity(20).refillGreedy(10, Duration.ofMinutes(1)))
                .build();
        };
    }

    @Override
    protected void doPost(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;

        String fromNumber = req.getParameter("from");
        String toNumber = req.getParameter("to");
        String text = req.getParameter("text");

        AsyncBucketProxy bucket = buckets.builder().build(fromNumber, configuration);
        CompletableFuture<ConsumptionProbe> limitCheckingFuture = bucket.asAsync().tryConsumeAndReturnRemaining(1);
        final AsyncContext asyncContext = req.startAsync();
        limitCheckingFuture.thenCompose(probe -> {
            if (!probe.isConsumed()) {
                Result throttledResult = Result.throttled(probe);
                return CompletableFuture.completedFuture(throttledResult);
            } else {
                CompletableFuture<Result> sendingFuture = smsSender.sendAsync(fromNumber, toNumber, text);
                return sendingFuture;
            }
        }).whenComplete((result, exception) -> {
            HttpServletResponse asyncResponse = (HttpServletResponse) asyncContext.getResponse();
            try {
                asyncResponse.setContentType("text/plain");
                if (exception != null || result.isFailed()) {
                    asyncResponse.setStatus(500);
                    asyncResponse.getWriter().println("Internal Error");
                } else if (result.isThrottled()) {
                    asyncResponse.setStatus(429);
                    asyncResponse.setHeader("X-Rate-Limit-Retry-After-Seconds", "" + result.getRetryAfter());
                    asyncResponse.getWriter().append("Too many requests");
                } else {
                    asyncResponse.setStatus(200);
                    asyncResponse.getWriter().append("Success");
                }
            } finally{
                asyncContext.complete();
            }
        });
    }

}