1 package de.juplo.kafka;
3 import lombok.RequiredArgsConstructor;
4 import lombok.extern.slf4j.Slf4j;
5 import org.apache.kafka.clients.consumer.*;
6 import org.apache.kafka.common.TopicPartition;
7 import org.apache.kafka.common.errors.RecordDeserializationException;
8 import org.apache.kafka.common.errors.WakeupException;
9 import org.springframework.stereotype.Component;
11 import javax.annotation.PreDestroy;
12 import java.time.Duration;
14 import java.util.concurrent.ExecutionException;
15 import java.util.concurrent.ExecutorService;
16 import java.util.concurrent.locks.Condition;
17 import java.util.concurrent.locks.Lock;
18 import java.util.concurrent.locks.ReentrantLock;
23 @RequiredArgsConstructor
24 public class EndlessConsumer implements Runnable
26 private final ExecutorService executor;
27 private final String id;
28 private final String topic;
29 private final Consumer<K, V> consumer;
30 private final ConsumerRebalanceListener rebalanceListener;
31 private final RecordHandler<K, V> recordHandler;
33 private final Lock lock = new ReentrantLock();
34 private final Condition condition = lock.newCondition();
35 private boolean running = false;
36 private Exception exception;
37 private long consumed = 0;
46 log.info("{} - Subscribing to topic {}", id, topic);
47 consumer.subscribe(Arrays.asList(topic), rebalanceListener);
51 ConsumerRecords<K, V> records =
52 consumer.poll(Duration.ofSeconds(1));
54 // Do something with the data...
55 log.info("{} - Received {} messages", id, records.count());
56 for (ConsumerRecord<K, V> record : records)
59 "{} - {}: {}/{} - {}={}",
68 recordHandler.accept(record);
74 catch(WakeupException e)
76 log.info("{} - RIIING! Request to stop consumption - commiting current offsets!", id);
77 consumer.commitSync();
80 catch(RecordDeserializationException e)
82 TopicPartition tp = e.topicPartition();
83 long offset = e.offset();
85 "{} - Could not deserialize message on topic {} with offset={}: {}",
89 e.getCause().toString());
91 consumer.commitSync();
96 log.error("{} - Unexpected error: {}", id, e.toString(), e);
101 log.info("{} - Consumer-Thread exiting", id);
105 private void shutdown()
110 private void shutdown(Exception e)
117 log.info("{} - Unsubscribing from topic {}", id, topic);
118 consumer.unsubscribe();
123 "{} - Error while unsubscribing from topic {}: {}",
147 throw new IllegalStateException("Consumer instance " + id + " is already running!");
149 log.info("{} - Starting - consumed {} messages before", id, consumed);
152 executor.submit(this);
160 public synchronized void stop() throws InterruptedException
166 throw new IllegalStateException("Consumer instance " + id + " is not running!");
168 log.info("{} - Stopping", id);
171 log.info("{} - Stopped - consumed {} messages so far", id, consumed);
180 public void destroy() throws ExecutionException, InterruptedException
182 log.info("{} - Destroy!", id);
183 log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
186 public boolean running()
199 public Optional<Exception> exitStatus()
205 throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
207 return Optional.ofNullable(exception);