Auf `@KafkaHandler` umgestellt
[demos/kafka/training] / src / main / java / de / juplo / kafka / EndlessConsumer.java
index 58557f2..d3d11ae 100644 (file)
@@ -2,55 +2,36 @@ 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.apache.kafka.clients.consumer.ConsumerRecord;
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.kafka.config.KafkaListenerEndpointRegistry;
 
-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;
+import java.util.List;
+import java.util.Optional;
 
 
-@Slf4j
 @RequiredArgsConstructor
-public class EndlessConsumer<K, V> implements Runnable
+@Slf4j
+public class EndlessConsumer<K, V>
 {
-  private final ExecutorService executor;
   private final String id;
-  private final String topic;
-  private final Consumer<K, V> consumer;
-  private final PollIntervalAwareConsumerRebalanceListener pollIntervalAwareRebalanceListener;
-  private final RecordHandler<K, V> handler;
-
-  private final Lock lock = new ReentrantLock();
-  private final Condition condition = lock.newCondition();
-  private boolean running = false;
-  private Exception exception;
-  private long consumed = 0;
+  private final KafkaListenerEndpointRegistry registry;
+  private final ApplicationErrorHandler errorHandler;
+  private final RecordHandler<K, V> recordHandler;
 
+  private long consumed = 0;
 
 
-  @Override
-  public void run()
+  @KafkaListener(
+      id = "${spring.kafka.client-id}",
+      idIsGroup = false,
+      topics = "${sumup.adder.topic}",
+      batch = "true",
+      autoStartup = "false")
+  public void accept(List<ConsumerRecord<K, V>> records)
   {
-    try
-    {
-      log.info("{} - Subscribing to topic {}", id, topic);
-      consumer.subscribe(Arrays.asList(topic), pollIntervalAwareRebalanceListener);
-
-      while (true)
-      {
-        ConsumerRecords<K, V> records =
-            consumer.poll(Duration.ofSeconds(1));
-
         // Do something with the data...
-        log.info("{} - Received {} messages", id, records.count());
+        log.info("{} - Received {} messages", id, records.size());
         for (ConsumerRecord<K, V> record : records)
         {
           log.info(
@@ -63,150 +44,42 @@ public class EndlessConsumer<K, V> implements Runnable
               record.value()
           );
 
-          handler.accept(record);
+          recordHandler.accept(record);
 
           consumed++;
         }
-
-        pollIntervalAwareRebalanceListener.beforeNextPoll();
-      }
-    }
-    catch(WakeupException e)
-    {
-      log.info("{} - RIIING! Request to stop consumption - commiting current offsets!", id);
-      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());
-
-      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();
-    }
-  }
+    if (running())
+      throw new IllegalStateException("Consumer instance " + id + " is already running!");
 
-  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();
-    }
+    log.info("{} - Starting - consumed {} messages before", id, consumed);
+    errorHandler.clearState();
+    registry.getListenerContainer(id).start();
   }
 
-  @PreDestroy
-  public void destroy() throws ExecutionException, InterruptedException
+  public void stop()
   {
-    log.info("{} - Destroy!", id);
-    log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
+    if (!running())
+      throw new IllegalStateException("Consumer instance " + id + " is not running!");
+
+    log.info("{} - Stopping", id);
+    registry.getListenerContainer(id).stop();
+    log.info("{} - Stopped - consumed {} messages so far", id, consumed);
   }
 
   public boolean running()
   {
-    lock.lock();
-    try
-    {
-      return running;
-    }
-    finally
-    {
-      lock.unlock();
-    }
+    return registry.getListenerContainer(id).isRunning();
   }
 
   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();
-    }
+    if (running())
+      throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
+
+    return errorHandler.getException();
   }
 }