Die Implementierung speichert Zustand & Offsets vor _jedem_ `poll()`

[demos/kafka/training] / src / main / java / de / juplo / kafka / EndlessConsumer.java

diff --git a/src/main/java/de/juplo/kafka/EndlessConsumer.java b/src/main/java/de/juplo/kafka/EndlessConsumer.java
index 8802df9..92802b9 100644 (file)
--- a/src/main/java/de/juplo/kafka/EndlessConsumer.java
+++ b/src/main/java/de/juplo/kafka/EndlessConsumer.java
@@ -19,13 +19,14 @@ import java.util.concurrent.locks.ReentrantLock;
 
 @Slf4j
 @RequiredArgsConstructor
-public class EndlessConsumer<K, V> implements ConsumerRebalanceListener, Runnable
+public class EndlessConsumer<K, V> implements Runnable
 {
   private final ExecutorService executor;
   private final String id;
   private final String topic;
   private final Consumer<K, V> consumer;
-  private final java.util.function.Consumer<ConsumerRecord<K, V>> handler;
+  private final RebalanceListener rebalanceListener;
+  private final RecordHandler<K, V> recordHandler;
 
   private final Lock lock = new ReentrantLock();
   private final Condition condition = lock.newCondition();
@@ -33,50 +34,6 @@ public class EndlessConsumer<K, V> implements ConsumerRebalanceListener, Runnabl
   private Exception exception;
   private long consumed = 0;
 
-  private final Map<Integer, Map<String, Long>> seen = new HashMap<>();
-  private final Map<Integer, Long> offsets = new HashMap<>();
-
-
-  @Override
-  public void onPartitionsRevoked(Collection<TopicPartition> partitions)
-  {
-    partitions.forEach(tp ->
-    {
-      Integer partition = tp.partition();
-      Long newOffset = consumer.position(tp);
-      Long oldOffset = offsets.remove(partition);
-      log.info(
-          "{} - removing partition: {}, consumed {} records (offset {} -> {})",
-          id,
-          partition,
-          newOffset - oldOffset,
-          oldOffset,
-          newOffset);
-      Map<String, Long> removed = seen.remove(partition);
-      for (String key : removed.keySet())
-      {
-        log.info(
-            "{} - Seen {} messages for partition={}|key={}",
-            id,
-            removed.get(key),
-            partition,
-            key);
-      }
-    });
-  }
-
-  @Override
-  public void onPartitionsAssigned(Collection<TopicPartition> partitions)
-  {
-    partitions.forEach(tp ->
-    {
-      Integer partition = tp.partition();
-      Long offset = consumer.position(tp);
-      log.info("{} - adding partition: {}, offset={}", id, partition, offset);
-      offsets.put(partition, offset);
-      seen.put(partition, new HashMap<>());
-    });
-  }
 
 
   @Override
@@ -85,7 +42,7 @@ public class EndlessConsumer<K, V> implements ConsumerRebalanceListener, Runnabl
     try
     {
       log.info("{} - Subscribing to topic {}", id, topic);
-      consumer.subscribe(Arrays.asList(topic), this);
+      consumer.subscribe(Arrays.asList(topic), rebalanceListener);
 
       while (true)
       {
@@ -106,21 +63,12 @@ public class EndlessConsumer<K, V> implements ConsumerRebalanceListener, Runnabl
               record.value()
           );
 
-          handler.accept(record);
+          recordHandler.accept(record);
 
           consumed++;
-
-          Integer partition = record.partition();
-          String key = record.key() == null ? "NULL" : record.key().toString();
-          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);
         }
+
+        rebalanceListener.beforeNextPoll();
       }
     }
     catch(WakeupException e)
@@ -190,11 +138,6 @@ public class EndlessConsumer<K, V> implements ConsumerRebalanceListener, Runnabl
     }
   }
 
-  public Map<Integer, Map<String, Long>> getSeen()
-  {
-    return seen;
-  }
-
   public void start()
   {
     lock.lock();
@@ -214,7 +157,7 @@ public class EndlessConsumer<K, V> implements ConsumerRebalanceListener, Runnabl
     }
   }
 
-  public synchronized void stop() throws ExecutionException, InterruptedException
+  public synchronized void stop() throws InterruptedException
   {
     lock.lock();
     try
@@ -237,22 +180,7 @@ public class EndlessConsumer<K, V> implements ConsumerRebalanceListener, Runnabl
   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);
-    }
+    log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
   }
 
   public boolean running()