import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
-import org.apache.kafka.clients.consumer.*;
-import org.apache.kafka.common.TopicPartition;
-import org.apache.kafka.common.errors.RecordDeserializationException;
-import org.apache.kafka.common.errors.WakeupException;
+import org.apache.kafka.clients.consumer.ConsumerRecord;
+import org.springframework.kafka.annotation.KafkaHandler;
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.kafka.config.KafkaListenerEndpointRegistry;
+import org.springframework.kafka.support.KafkaHeaders;
+import org.springframework.messaging.handler.annotation.Header;
+import org.springframework.messaging.handler.annotation.Payload;
-import javax.annotation.PreDestroy;
-import java.time.Duration;
-import java.util.*;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.locks.Condition;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReentrantLock;
+import java.util.List;
+import java.util.Optional;
-@Slf4j
@RequiredArgsConstructor
-public class EndlessConsumer<K, V> implements Runnable
+@Slf4j
+@KafkaListener(
+ id = "${spring.kafka.client-id}",
+ idIsGroup = false,
+ topics = "${sumup.adder.topic}",
+ autoStartup = "false")
+public class EndlessConsumer
{
- private final ExecutorService executor;
private final String id;
- private final String topic;
- private final Consumer<K, V> consumer;
- private final ConsumerRebalanceListener rebalanceListener;
- private final RecordHandler<K, V> recordHandler;
-
- private final Lock lock = new ReentrantLock();
- private final Condition condition = lock.newCondition();
- private boolean running = false;
- private Exception exception;
- private long consumed = 0;
+ private final KafkaListenerEndpointRegistry registry;
+ private final RecordHandler recordHandler;
+ private long consumed = 0;
- @Override
- public void run()
+ @KafkaHandler
+ public void addNumber(
+ @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY) String key,
+ @Header(KafkaHeaders.RECEIVED_TOPIC) String topic,
+ @Header(KafkaHeaders.RECEIVED_PARTITION_ID) Integer partition,
+ @Header(KafkaHeaders.OFFSET) Long offset,
+ @Payload MessageAddNumber message)
{
- try
- {
- log.info("{} - Subscribing to topic {}", id, topic);
- consumer.subscribe(Arrays.asList(topic), rebalanceListener);
-
- while (true)
- {
- ConsumerRecords<K, V> records =
- consumer.poll(Duration.ofSeconds(1));
-
- // Do something with the data...
- log.info("{} - Received {} messages", id, records.count());
- for (ConsumerRecord<K, V> record : records)
- {
log.info(
"{} - {}: {}/{} - {}={}",
id,
- record.offset(),
- record.topic(),
- record.partition(),
- record.key(),
- record.value()
+ offset,
+ topic,
+ partition,
+ key,
+ message
);
- recordHandler.accept(record);
+ recordHandler.addNumber(topic, partition, offset, key, message);
consumed++;
- }
- }
- }
- catch(WakeupException e)
- {
- log.info("{} - RIIING! Request to stop consumption.", id);
- shutdown();
- }
- catch(RecordDeserializationException e)
- {
- TopicPartition tp = e.topicPartition();
- long offset = e.offset();
- log.error(
- "{} - Could not deserialize message on topic {} with offset={}: {}",
- id,
- tp,
- offset,
- e.getCause().toString());
-
- shutdown(e);
- }
- catch(Exception e)
- {
- log.error("{} - Unexpected error: {}", id, e.toString(), e);
- shutdown(e);
- }
- finally
- {
- log.info("{} - Consumer-Thread exiting", id);
- }
}
- private void shutdown()
+ @KafkaHandler
+ public void calculateSum(
+ @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY) String key,
+ @Header(KafkaHeaders.RECEIVED_TOPIC) String topic,
+ @Header(KafkaHeaders.RECEIVED_PARTITION_ID) Integer partition,
+ @Header(KafkaHeaders.OFFSET) Long offset,
+ @Payload MessageCalculateSum message)
{
- shutdown(null);
- }
+ log.info(
+ "{} - {}: {}/{} - {}={}",
+ id,
+ offset,
+ topic,
+ partition,
+ key,
+ message
+ );
- private void shutdown(Exception e)
- {
- lock.lock();
- try
- {
- try
- {
- log.info("{} - Unsubscribing from topic {}", id, topic);
- consumer.unsubscribe();
- }
- catch (Exception ue)
- {
- log.error(
- "{} - Error while unsubscribing from topic {}: {}",
- id,
- topic,
- ue.toString());
- }
- finally
- {
- running = false;
- exception = e;
- condition.signal();
- }
- }
- finally
- {
- lock.unlock();
- }
+ recordHandler.calculateSum(topic, partition, offset, key, message);
+
+ consumed++;
}
public void start()
{
- lock.lock();
- try
- {
- if (running)
- throw new IllegalStateException("Consumer instance " + id + " is already running!");
-
- log.info("{} - Starting - consumed {} messages before", id, consumed);
- running = true;
- exception = null;
- executor.submit(this);
- }
- finally
- {
- lock.unlock();
- }
- }
+ if (running())
+ throw new IllegalStateException("Consumer instance " + id + " is already running!");
- public synchronized void stop() throws InterruptedException
- {
- lock.lock();
- try
- {
- if (!running)
- throw new IllegalStateException("Consumer instance " + id + " is not running!");
-
- log.info("{} - Stopping", id);
- consumer.wakeup();
- condition.await();
- log.info("{} - Stopped - consumed {} messages so far", id, consumed);
- }
- finally
- {
- lock.unlock();
- }
+ log.info("{} - Starting - consumed {} messages before", id, consumed);
+ registry.getListenerContainer(id).start();
}
- @PreDestroy
- public void destroy() throws ExecutionException, InterruptedException
+ public void stop()
{
- log.info("{} - Destroy!", id);
- log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
- }
+ if (!running())
+ throw new IllegalStateException("Consumer instance " + id + " is not running!");
- public boolean running()
- {
- lock.lock();
- try
- {
- return running;
- }
- finally
- {
- lock.unlock();
- }
+ log.info("{} - Stopping", id);
+ registry.getListenerContainer(id).stop();
+ log.info("{} - Stopped - consumed {} messages so far", id, consumed);
}
- public Optional<Exception> exitStatus()
+ public boolean running()
{
- lock.lock();
- try
- {
- if (running)
- throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
-
- return Optional.ofNullable(exception);
- }
- finally
- {
- lock.unlock();
- }
+ return registry.getListenerContainer(id).isRunning();
}
}
projects / demos / kafka / training / blobdiff