package de.juplo.kafka;
+import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.consumer.ConsumerRecord;
-import org.apache.kafka.clients.consumer.ConsumerRecords;
-import org.apache.kafka.clients.consumer.KafkaConsumer;
-import org.apache.kafka.common.errors.WakeupException;
-import org.apache.kafka.common.serialization.StringDeserializer;
-
-import javax.annotation.PreDestroy;
-import java.time.Duration;
-import java.util.Arrays;
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.kafka.config.KafkaListenerEndpointRegistry;
+
+import java.util.List;
import java.util.Optional;
-import java.util.Properties;
-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;
+@RequiredArgsConstructor
@Slf4j
-public class EndlessConsumer implements Runnable
+public class EndlessConsumer<K, V>
{
- private final ExecutorService executor;
- private final String bootstrapServer;
- private final String groupId;
private final String id;
- private final String topic;
- private final String autoOffsetReset;
+ private final KafkaListenerEndpointRegistry registry;
+ private final ApplicationErrorHandler errorHandler;
+ 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 KafkaConsumer<String, String> consumer = null;
-
- public EndlessConsumer(
- ExecutorService executor,
- String bootstrapServer,
- String groupId,
- String clientId,
- String topic,
- String autoOffsetReset)
- {
- this.executor = executor;
- this.bootstrapServer = bootstrapServer;
- this.groupId = groupId;
- this.id = clientId;
- this.topic = topic;
- this.autoOffsetReset = autoOffsetReset;
- }
- @Override
- public void run()
+ @KafkaListener(
+ id = "${spring.kafka.client-id}",
+ idIsGroup = false,
+ topics = "${sumup.adder.topic}",
+ autoStartup = "false")
+ public void accept(ConsumerRecord<K, V> record)
{
- try
- {
- Properties props = new Properties();
- props.put("bootstrap.servers", bootstrapServer);
- props.put("group.id", groupId);
- props.put("client.id", id);
- props.put("auto.offset.reset", autoOffsetReset);
- props.put("key.deserializer", StringDeserializer.class.getName());
- props.put("value.deserializer", StringDeserializer.class.getName());
-
- this.consumer = new KafkaConsumer<>(props);
-
- log.info("{} - Subscribing to topic {}", id, topic);
- consumer.subscribe(Arrays.asList(topic));
-
- while (true)
- {
- ConsumerRecords<String, String> records =
- consumer.poll(Duration.ofSeconds(1));
-
- // Do something with the data...
- log.info("{} - Received {} messages", id, records.count());
- for (ConsumerRecord<String, String> record : records)
- {
- consumed++;
log.info(
"{} - {}: {}/{} - {}={}",
id,
record.key(),
record.value()
);
- }
- }
- }
- catch(WakeupException e)
- {
- log.info("{} - RIIING!", id);
- shutdown();
- }
- catch(Exception e)
- {
- log.error("{} - Unexpected error: {}", id, e.toString(), e);
- shutdown(e);
- }
- finally
- {
- log.info("{} - Closing the KafkaConsumer", id);
- consumer.close();
- log.info("{} - Consumer-Thread exiting", id);
- }
- }
- private void shutdown()
- {
- shutdown(null);
- }
+ recordHandler.accept(record);
- private void shutdown(Exception e)
- {
- lock.lock();
- try
- {
- running = false;
- exception = e;
- condition.signal();
- }
- finally
- {
- lock.unlock();
- }
+ 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 ExecutionException, 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);
+ errorHandler.clearState();
+ registry.getListenerContainer(id).start();
}
- @PreDestroy
- public void destroy() throws ExecutionException, InterruptedException
+ public void stop()
{
- 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);
- }
+ if (!running())
+ throw new IllegalStateException("Consumer instance " + id + " is not running!");
+
+ log.info("{} - Stopping", id);
+ registry.getListenerContainer(id).stop();
+ log.info("{} - Stopped - consumed {} messages so far", id, consumed);
}
public boolean running()
{
- lock.lock();
- try
- {
- return running;
- }
- finally
- {
- lock.unlock();
- }
+ return registry.getListenerContainer(id).isRunning();
}
public Optional<Exception> exitStatus()
{
- lock.lock();
- try
- {
- if (running)
- throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
-
- return Optional.ofNullable(exception);
- }
- finally
- {
- lock.unlock();
- }
+ if (running())
+ throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
+
+ return errorHandler.getException();
}
}