X-Git-Url: http://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2FEndlessConsumer.java;h=b173b12cea4be841c82a944695bc702314c28e86;hb=fb966920f18413076a28876ffcd125c84f9a6f06;hp=6af3765d0532a59f821d031927d3cc38de2400bf;hpb=d1ce252495c63a971d1734a35b10cf26313d95fb;p=demos%2Fkafka%2Ftraining

diff --git a/src/main/java/de/juplo/kafka/EndlessConsumer.java b/src/main/java/de/juplo/kafka/EndlessConsumer.java
index 6af3765..b173b12 100644
--- a/src/main/java/de/juplo/kafka/EndlessConsumer.java
+++ b/src/main/java/de/juplo/kafka/EndlessConsumer.java
@@ -1,13 +1,11 @@
 package de.juplo.kafka;
 
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.apache.kafka.clients.consumer.ConsumerRebalanceListener;
-import org.apache.kafka.clients.consumer.ConsumerRecord;
-import org.apache.kafka.clients.consumer.ConsumerRecords;
-import org.apache.kafka.clients.consumer.KafkaConsumer;
+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.common.serialization.StringDeserializer;
 
 import javax.annotation.PreDestroy;
 import java.time.Duration;
@@ -20,59 +18,30 @@ import java.util.concurrent.locks.ReentrantLock;
 
 
 @Slf4j
-public class EndlessConsumer implements Runnable
+@RequiredArgsConstructor
+public class EndlessConsumer<K, V> implements Runnable
 {
   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 Consumer<K, V> consumer;
+  private final java.util.function.Consumer<ConsumerRecord<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 KafkaConsumer<String, String> consumer = null;
-
 
   private final Map<Integer, Map<String, Long>> seen = new HashMap<>();
   private final Map<Integer, Long> offsets = 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()
       {
@@ -120,14 +89,13 @@ public class EndlessConsumer implements Runnable
 
       while (true)
       {
-        ConsumerRecords<String, String> records =
+        ConsumerRecords<K, V> records =
             consumer.poll(Duration.ofSeconds(1));
 
         // Do something with the data...
         log.info("{} - Received {} messages", id, records.count());
-        for (ConsumerRecord<String, String> record : records)
+        for (ConsumerRecord<K, V> record : records)
         {
-          consumed++;
           log.info(
               "{} - {}: {}/{} - {}={}",
               id,
@@ -138,8 +106,12 @@ public class EndlessConsumer implements Runnable
               record.value()
           );
 
+          handler.accept(record);
+
+          consumed++;
+
           Integer partition = record.partition();
-          String key = record.key() == null ? "NULL" : record.key();
+          String key = record.key() == null ? "NULL" : record.key().toString();
           Map<String, Long> byKey = seen.get(partition);
 
           if (!byKey.containsKey(key))
@@ -153,9 +125,24 @@ public class EndlessConsumer implements Runnable
     }
     catch(WakeupException e)
     {
-      log.info("{} - RIIING!", id);
+      log.info("{} - RIIING! Request to stop consumption - commiting current offsets!", id);
+      consumer.commitSync();
       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());
+
+      consumer.commitSync();
+      shutdown(e);
+    }
     catch(Exception e)
     {
       log.error("{} - Unexpected error: {}", id, e.toString(), e);
@@ -163,8 +150,6 @@ public class EndlessConsumer implements Runnable
     }
     finally
     {
-      log.info("{} - Closing the KafkaConsumer", id);
-      consumer.close();
       log.info("{} - Consumer-Thread exiting", id);
     }
   }
@@ -179,9 +164,25 @@ public class EndlessConsumer implements Runnable
     lock.lock();
     try
     {
-      running = false;
-      exception = e;
-      condition.signal();
+      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
     {