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;
10 import javax.annotation.PreDestroy;
11 import java.time.Duration;
13 import java.util.concurrent.ExecutionException;
14 import java.util.concurrent.ExecutorService;
15 import java.util.concurrent.locks.Condition;
16 import java.util.concurrent.locks.Lock;
17 import java.util.concurrent.locks.ReentrantLock;
21 @RequiredArgsConstructor
22 public class EndlessConsumer<K, V> implements Runnable
24 private final ExecutorService executor;
25 private final String id;
26 private final String topic;
27 private final Consumer<K, V> consumer;
28 private final CommittingConsumerRebalanceListener rebalanceListener;
29 private final RecordHandler<K, V> recordHandler;
31 private final Lock lock = new ReentrantLock();
32 private final Condition condition = lock.newCondition();
33 private boolean running = false;
34 private Exception exception;
35 private long consumed = 0;
44 log.info("{} - Subscribing to topic {}", id, topic);
45 rebalanceListener.enableCommits();
46 consumer.subscribe(Arrays.asList(topic), rebalanceListener);
50 ConsumerRecords<K, V> records =
51 consumer.poll(Duration.ofSeconds(1));
53 // Do something with the data...
54 log.info("{} - Received {} messages", id, records.count());
55 for (ConsumerRecord<K, V> record : records)
58 "{} - {}: {}/{} - {}={}",
67 recordHandler.accept(record);
73 catch(WakeupException e)
75 log.info("{} - RIIING! Request to stop consumption.", id);
78 catch(RecordDeserializationException e)
80 TopicPartition tp = e.topicPartition();
81 long offset = e.offset();
83 "{} - Could not deserialize message on topic {} with offset={}: {}",
87 e.getCause().toString());
93 log.error("{} - Unexpected error: {}, disabling commits", id, e.toString(), e);
94 rebalanceListener.disableCommits();
99 log.info("{} - Consumer-Thread exiting", id);
103 private void shutdown()
108 private void shutdown(Exception e)
115 log.info("{} - Unsubscribing from topic {}", id, topic);
116 consumer.unsubscribe();
121 "{} - Error while unsubscribing from topic {}: {}",
145 throw new IllegalStateException("Consumer instance " + id + " is already running!");
147 log.info("{} - Starting - consumed {} messages before", id, consumed);
150 executor.submit(this);
158 public synchronized void stop() throws InterruptedException
164 throw new IllegalStateException("Consumer instance " + id + " is not running!");
166 log.info("{} - Stopping", id);
169 log.info("{} - Stopped - consumed {} messages so far", id, consumed);
178 public void destroy() throws ExecutionException, InterruptedException
180 log.info("{} - Destroy!", id);
181 log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
184 public boolean running()
197 public Optional<Exception> exitStatus()
203 throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
205 return Optional.ofNullable(exception);