import org.springframework.kafka.core.ConsumerFactory;
import javax.annotation.PreDestroy;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Future;
@SpringBootApplication
@Slf4j
public class Application implements ApplicationRunner
{
+ @Autowired
+ ExecutorService executorService;
@Autowired
Consumer<String, Message> consumer;
@Autowired
SimpleConsumer simpleConsumer;
+ Future<?> consumerJob;
@Override
public void run(ApplicationArguments args) throws Exception
{
- log.info("Starting EndlessConsumer");
- simpleConsumer.start();
+ log.info("Starting SimpleConsumer");
+ consumerJob = executorService.submit(simpleConsumer);
}
@PreDestroy
- public void shutdown()
+ public void shutdown() throws ExecutionException, InterruptedException
{
- log.info("Signaling the consumer to quit its work");
+ log.info("Signaling SimpleConsumer to quit its work");
consumer.wakeup();
+ log.info("Waiting for SimpleConsumer to finish its work");
+ consumerJob.get();
+ log.info("SimpleConsumer finished its work");
}
@Bean(destroyMethod = "close")
+++ /dev/null
-package de.juplo.kafka;
-
-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.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;
-
-
-@Component
-@Slf4j
-@RequiredArgsConstructor
-public class EndlessConsumer implements Runnable
-{
- 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;
-
-
-
- @Override
- public void run()
- {
- 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()
- );
-
- recordHandler.accept(record);
-
- consumed++;
- }
- }
- }
- 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);
- }
- }
-
- private void shutdown()
- {
- shutdown(null);
- }
-
- 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();
- }
- }
-
- 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();
- }
- }
-
- 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();
- }
- }
-
- @PreDestroy
- public void destroy() throws ExecutionException, InterruptedException
- {
- log.info("{} - Destroy!", id);
- log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
- }
-
- public boolean running()
- {
- lock.lock();
- try
- {
- return running;
- }
- finally
- {
- lock.unlock();
- }
- }
-
- 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();
- }
- }
-}