import java.util.Properties;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Future;
-import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
@Slf4j
private final String groupId;
private final String id;
private final String topic;
+ private final String autoOffsetReset;
- private AtomicBoolean running = new AtomicBoolean();
+ private final Lock lock = new ReentrantLock();
+ private final Condition condition = lock.newCondition();
+ private boolean running = false;
private long consumed = 0;
private KafkaConsumer<String, String> consumer = null;
- private Future<?> future = null;
+
public EndlessConsumer(
ExecutorService executor,
String bootstrapServer,
String groupId,
String clientId,
- String topic)
+ 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()
{
- Properties props = new Properties();
- props.put("bootstrap.servers", bootstrapServer);
- props.put("group.id", groupId);
- props.put("client.id", id);
- props.put("auto.offset.reset", "earliest");
- props.put("key.deserializer", StringDeserializer.class.getName());
- props.put("value.deserializer", StringDeserializer.class.getName());
-
- this.consumer = new KafkaConsumer<>(props);
-
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));
catch(WakeupException e)
{
log.info("{} - RIIING!", id);
+ shutdown();
}
catch(Exception e)
{
- log.error("{} - Unexpected error: {}", id, e.toString());
- running.set(false); // Mark the instance as not running
+ log.error("{} - Unexpected error: {}", id, e.toString(), e);
+ shutdown();
}
finally
{
}
}
+ private void shutdown()
+ {
+ lock.lock();
+ try
+ {
+ running = false;
+ condition.signal();
+ }
+ finally
+ {
+ lock.unlock();
+ }
+ }
- public synchronized void start()
+ public void start()
{
- boolean stateChanged = running.compareAndSet(false, true);
- if (!stateChanged)
- throw new RuntimeException("Consumer instance " + id + " is already running!");
+ lock.lock();
+ try
+ {
+ if (running)
+ throw new IllegalStateException("Consumer instance " + id + " is already running!");
- log.info("{} - Starting - consumed {} messages before", id, consumed);
- future = executor.submit(this);
+ log.info("{} - Starting - consumed {} messages before", id, consumed);
+ running = true;
+ executor.submit(this);
+ }
+ finally
+ {
+ lock.unlock();
+ }
}
public synchronized void stop() throws ExecutionException, InterruptedException
{
- boolean stateChanged = running.compareAndSet(true, false);
- if (!stateChanged)
- throw new RuntimeException("Consumer instance " + id + " is not running!");
-
- log.info("{} - Stopping", id);
- consumer.wakeup();
- future.get();
- log.info("{} - Stopped - consumed {} messages so far", id, consumed);
+ 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
{
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);