X-Git-Url: https://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2FEndlessConsumer.java;h=9ea944b9039812dd3c0a6d4f1dcd10286d1f67bf;hb=eba11d4859d1e2b936bcd9e8075986b5179b32ea;hp=22dce95ee17a7c6c9f089bbe5e9377fe8bdcdba3;hpb=e87f4bb2bc188252955fb4932ddd99161ba621d3;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 22dce95..9ea944b 100644
--- a/src/main/java/de/juplo/kafka/EndlessConsumer.java
+++ b/src/main/java/de/juplo/kafka/EndlessConsumer.java
@@ -1,78 +1,53 @@
 package de.juplo.kafka;
 
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-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 org.springframework.context.ConfigurableApplicationContext;
 
-import javax.annotation.PreDestroy;
 import java.time.Duration;
-import java.util.Arrays;
-import java.util.Properties;
-import java.util.concurrent.ExecutionException;
+import java.util.*;
 import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Future;
-import java.util.concurrent.atomic.AtomicBoolean;
 
 
 @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 ConfigurableApplicationContext applicationContext;
   private final String id;
   private final String topic;
+  private final Consumer<K, V> consumer;
+  private final ConsumerRebalanceListener rebalanceListener;
+  private final RecordHandler<K, V> recordHandler;
 
-  private AtomicBoolean running = new AtomicBoolean();
+  private boolean running = false;
+  private Exception exception = null;
   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)
-  {
-    this.executor = executor;
-    this.bootstrapServer = bootstrapServer;
-    this.groupId = groupId;
-    this.id = clientId;
-    this.topic = topic;
-  }
+
+
 
   @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
     {
       log.info("{} - Subscribing to topic {}", id, topic);
-      consumer.subscribe(Arrays.asList(topic));
+      consumer.subscribe(Arrays.asList(topic), rebalanceListener);
 
       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,
@@ -82,64 +57,71 @@ public class EndlessConsumer implements Runnable
               record.key(),
               record.value()
           );
+
+          recordHandler.accept(record);
+
+          consumed++;
         }
       }
     }
     catch(WakeupException e)
     {
-      log.info("{} - RIIING!", id);
+      log.info("{} - RIIING! Request to stop consumption - commiting current offsets!", id);
+    }
+    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());
+      this.exception = e;
     }
     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);
+      this.exception = e;
+      log.info("{} - Unsubscribing...", id);
+      consumer.unsubscribe();
     }
     finally
     {
-      log.info("{} - Closing the KafkaConsumer", id);
+      running = false;
+      log.info("{} - Closing the consumer...", id);
       consumer.close();
+      log.info("{} - Shutting down the app...", id);
+      applicationContext.close();
       log.info("{} - Consumer-Thread exiting", id);
     }
   }
 
-
-  public synchronized void start()
+  public void start()
   {
-    boolean stateChanged = running.compareAndSet(false, true);
-    if (!stateChanged)
-      throw new RuntimeException("Consumer instance " + id + " is already running!");
+    if (running)
+      throw new IllegalStateException("Consumer instance " + id + " is already running!");
 
     log.info("{} - Starting - consumed {} messages before", id, consumed);
-    future = executor.submit(this);
+    running = true;
+    executor.submit(this);
   }
 
-  public synchronized void stop() throws ExecutionException, InterruptedException
+  public void stop()
   {
-    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);
+  }
+  public boolean running()
+  {
+    return running;
   }
 
-  @PreDestroy
-  public void destroy() throws ExecutionException, InterruptedException
+  public Optional<Exception> exitStatus()
   {
-    log.info("{} - Destroy!", id);
-    try
-    {
-      stop();
-    }
-    catch (IllegalStateException e)
-    {
-      log.info("{} - Was already stopped", id);
-    }
-    finally
-    {
-      log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
-    }
+    if (running)
+      throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
+
+    return Optional.ofNullable(exception);
   }
 }