X-Git-Url: https://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2FEndlessConsumer.java;h=9ea944b9039812dd3c0a6d4f1dcd10286d1f67bf;hb=eba11d4859d1e2b936bcd9e8075986b5179b32ea;hp=bc3d3571ad4ab7c450c5c7408f5ebeafe32ed22e;hpb=262d13bfa0274005b050c7b271f867acd9809f8b;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 bc3d357..9ea944b 100644
--- a/src/main/java/de/juplo/kafka/EndlessConsumer.java
+++ b/src/main/java/de/juplo/kafka/EndlessConsumer.java
@@ -1,120 +1,53 @@
 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 org.springframework.context.ConfigurableApplicationContext;
 
-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;
 
 
 @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 String autoOffsetReset;
+  private final Consumer<K, V> consumer;
+  private final ConsumerRebalanceListener rebalanceListener;
+  private final RecordHandler<K, V> recordHandler;
 
-  private final Lock lock = new ReentrantLock();
-  private final Condition condition = lock.newCondition();
   private boolean running = false;
-  private Exception exception;
+  private Exception exception = null;
   private long consumed = 0;
-  private KafkaConsumer<String, String> consumer = null;
 
 
-  private final Map<Integer, Map<String, Long>> seen = 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()
-      {
-        @Override
-        public void onPartitionsRevoked(Collection<TopicPartition> partitions)
-        {
-          partitions.forEach(tp ->
-          {
-            log.info("{} - removing partition: {}", id, tp);
-            Map<String, Long> removed = seen.remove(tp.partition());
-            for (String key : removed.keySet())
-            {
-              log.info(
-                  "{} - Seen {} messages for partition={}|key={}",
-                  id,
-                  removed.get(key),
-                  tp.partition(),
-                  key);
-            }
-          });
-        }
-
-        @Override
-        public void onPartitionsAssigned(Collection<TopicPartition> partitions)
-        {
-          partitions.forEach(tp ->
-          {
-            log.info("{} - adding partition: {}", id, tp);
-            seen.put(tp.partition(), new HashMap<>());
-          });
-        }
-      });
+      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,
@@ -125,148 +58,70 @@ public class EndlessConsumer implements Runnable
               record.value()
           );
 
-          Integer partition = record.partition();
-          String key = record.key() == null ? "NULL" : record.key();
-          Map<String, Long> byKey = seen.get(partition);
+          recordHandler.accept(record);
 
-          if (!byKey.containsKey(key))
-            byKey.put(key, 0l);
-
-          long seenByKey = byKey.get(key);
-          seenByKey++;
-          byKey.put(key, seenByKey);
+          consumed++;
         }
       }
     }
     catch(WakeupException e)
     {
-      log.info("{} - RIIING!", id);
-      shutdown();
+      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(), e);
-      shutdown(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);
     }
   }
 
-  private void shutdown()
-  {
-    shutdown(null);
-  }
-
-  private void shutdown(Exception e)
-  {
-    lock.lock();
-    try
-    {
-      running = false;
-      exception = e;
-      condition.signal();
-    }
-    finally
-    {
-      lock.unlock();
-    }
-  }
-
-  public Map<Integer, Map<String, Long>> getSeen()
-  {
-    return seen;
-  }
-
   public void start()
   {
-    lock.lock();
-    try
-    {
-      if (running)
-        throw new IllegalStateException("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);
-      running = true;
-      exception = null;
-      executor.submit(this);
-    }
-    finally
-    {
-      lock.unlock();
-    }
-  }
-
-  public synchronized void stop() throws ExecutionException, 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);
+    running = true;
+    executor.submit(this);
   }
 
-  @PreDestroy
-  public void destroy() throws ExecutionException, InterruptedException
+  public void stop()
   {
-    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);
-    }
+    consumer.wakeup();
   }
-
   public boolean running()
   {
-    lock.lock();
-    try
-    {
-      return running;
-    }
-    finally
-    {
-      lock.unlock();
-    }
+    return running;
   }
 
   public Optional<Exception> exitStatus()
   {
-    lock.lock();
-    try
-    {
-      if (running)
-        throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
+    if (running)
+      throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
 
-      return Optional.ofNullable(exception);
-    }
-    finally
-    {
-      lock.unlock();
-    }
+    return Optional.ofNullable(exception);
   }
 }