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.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.kafka.config.KafkaListenerEndpointRegistry;
+import org.springframework.stereotype.Component;
-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.Optional;
+import java.util.function.Consumer;
+@Component
@Slf4j
@RequiredArgsConstructor
-public class EndlessConsumer<K, V> implements Runnable
+public class EndlessConsumer<K, V>
{
- private final ExecutorService executor;
- private final String id;
- private final String topic;
- private final Consumer<K, V> consumer;
- private final java.util.function.Consumer<ConsumerRecord<K, V>> handler;
+ @Autowired
+ private KafkaListenerEndpointRegistry registry;
- @Value("${consumer.client-id}")
++ @Value("${spring.kafka.consumer.client-id}")
+ String id;
+ @Autowired
+ Consumer<ConsumerRecord<K, V>> handler;
+ @Autowired
+ ApplicationErrorHandler errorHandler;
- 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 Map<Integer, Map<String, Long>> seen = new HashMap<>();
- private final Map<Integer, Long> offsets = new HashMap<>();
-
-
- @Override
- public void run()
+ @KafkaListener(
- id = "${consumer.client-id}",
++ id = "${spring.kafka.consumer.client-id}",
+ idIsGroup = false,
+ topics = "${consumer.topic}",
+ autoStartup = "false")
+ public void receive(ConsumerRecord<K, V> record)
{
- try
- {
- log.info("{} - Subscribing to topic {}", id, topic);
- consumer.subscribe(Arrays.asList(topic), new ConsumerRebalanceListener()
- {
- @Override
- public void onPartitionsRevoked(Collection<TopicPartition> partitions)
- {
- partitions.forEach(tp ->
- {
- Integer partition = tp.partition();
- Long newOffset = consumer.position(tp);
- Long oldOffset = offsets.remove(partition);
- log.info(
- "{} - removing partition: {}, consumed {} records (offset {} -> {})",
- id,
- partition,
- newOffset - oldOffset,
- oldOffset,
- newOffset);
- Map<String, Long> removed = seen.remove(partition);
- for (String key : removed.keySet())
- {
- log.info(
- "{} - Seen {} messages for partition={}|key={}",
- id,
- removed.get(key),
- partition,
- key);
- }
- });
- }
-
- @Override
- public void onPartitionsAssigned(Collection<TopicPartition> partitions)
- {
- partitions.forEach(tp ->
- {
- Integer partition = tp.partition();
- Long offset = consumer.position(tp);
- log.info("{} - adding partition: {}, offset={}", id, partition, offset);
- offsets.put(partition, offset);
- seen.put(partition, new HashMap<>());
- });
- }
- });
-
- 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()
- );
-
- handler.accept(record);
-
- consumed++;
-
- Integer partition = record.partition();
- String key = record.key() == null ? "NULL" : record.key().toString();
- Map<String, Long> byKey = seen.get(partition);
-
- if (!byKey.containsKey(key))
- byKey.put(key, 0l);
-
- long seenByKey = byKey.get(key);
- seenByKey++;
- byKey.put(key, seenByKey);
- }
- }
- }
- catch(WakeupException e)
- {
- log.info("{} - RIIING! Request to stop consumption - commiting current offsets!", id);
- consumer.commitSync();
- 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());
-
- consumer.commitSync();
- shutdown(e);
- }
- catch(Exception e)
- {
- log.error("{} - Unexpected error: {}", id, e.toString(), e);
- shutdown(e);
- }
- finally
- {
- log.info("{} - Consumer-Thread exiting", id);
- }
+ log.info(
+ "{} - {}: {}/{} - {}={}",
+ id,
+ record.offset(),
+ record.topic(),
+ record.partition(),
+ record.key(),
+ record.value()
+ );
+
+ handler.accept(record);
+
+ consumed++;
}
- private void shutdown()
- {
- shutdown(null);
- }
- private void shutdown(Exception e)
+ public synchronized void start()
{
- 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();
- }
- }
-
- public Map<Integer, Map<String, Long>> getSeen()
- {
- return seen;
- }
-
- public void start()
- {
- lock.lock();
- try
- {
- if (running)
- throw new IllegalStateException("Consumer instance " + id + " is already running!");
+ if (registry.getListenerContainer(id).isChildRunning())
+ 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();
- }
+ log.info("{} - Starting - consumed {} messages before", id, consumed);
+ errorHandler.clearException();
+ registry.getListenerContainer(id).start();
}
- public synchronized void stop() throws ExecutionException, InterruptedException
+ public synchronized void stop()
{
- lock.lock();
- try
- {
- if (!running)
- throw new IllegalStateException("Consumer instance " + id + " is not running!");
+ if (!registry.getListenerContainer(id).isChildRunning())
+ 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();
- }
- }
-
- @PreDestroy
- public void destroy() throws ExecutionException, InterruptedException
- {
- log.info("{} - Destroy!", id);
- try
- {
- stop();
- }
- catch (IllegalStateException e)
- {
- log.info("{} - Was already stopped", id);
- }
- catch (Exception e)
- {
- log.error("{} - Unexpected exception while trying to stop the consumer", id, e);
- }
- finally
- {
- log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
- }
- }
-
- 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 synchronized Optional<Exception> exitStatus()
{
- lock.lock();
- try
- {
- if (running)
- throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
+ if (registry.getListenerContainer(id).isChildRunning())
+ throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
- return Optional.ofNullable(exception);
- }
- finally
- {
- lock.unlock();
- }
+ return errorHandler.getException();
}
}
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