- 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 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;
-
-
- private final Map<Integer, Map<String, Long>> seen = new HashMap<>();
-
-
- 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()
- {
- 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("metadata.max.age.ms", "1000");
- 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), new ConsumerRebalanceListener()
- {
- @Override
- public void onPartitionsRevoked(Collection<TopicPartition> partitions)
- {
- partitions.forEach(tp ->
- {
- log.info("{} - removing partition: {}", id, tp);
- Map<String, Long> removed = seen.remove(tp.partition());
- for (String key : removed.keySet())
- {
- log.info(
- "{} - Seen {} messages for partition={}|key={}",
- id,
- removed.get(key),
- tp.partition(),
- key);
- }
- });
- }
-
- @Override
- public void onPartitionsAssigned(Collection<TopicPartition> partitions)
- {
- partitions.forEach(tp ->
- {
- log.info("{} - adding partition: {}", id, tp);
- seen.put(tp.partition(), new HashMap<>());
- });
- }
- });
-
- 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.offset(),
- record.topic(),
- record.partition(),
- record.key(),
- record.value()
- );
-
- Integer partition = record.partition();
- String key = record.key() == null ? "NULL" : record.key();
- 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!", 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);
- }
-
- private void shutdown(Exception e)
- {
- lock.lock();
- try
- {
- 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!");
-
- log.info("{} - Starting - consumed {} messages before", id, consumed);
- running = true;
- exception = null;
- executor.submit(this);
- }
- finally
- {
- lock.unlock();
- }
- }
-
- 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();
- }
- }
-
- @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();
- }
- }
-
- 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();