X-Git-Url: http://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2FEndlessConsumer.java;h=2310ccd7fe7306f4b0e7f5f5081fdd16c5846380;hb=f9c0ba7779552d8fcfc9cb29c8b689e20c314904;hp=9aa81525b6c9899644600308bb2f23609c44a453;hpb=ae2e7a02860a3ac4b26073bf0bf000a84fe894b9;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 9aa8152..2310ccd 100644
--- a/src/main/java/de/juplo/kafka/EndlessConsumer.java
+++ b/src/main/java/de/juplo/kafka/EndlessConsumer.java
@@ -1,21 +1,24 @@
 package de.juplo.kafka;
 
 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.common.TopicPartition;
 import org.apache.kafka.common.errors.WakeupException;
 import org.apache.kafka.common.serialization.StringDeserializer;
 
 import javax.annotation.PreDestroy;
 import java.time.Duration;
-import java.util.*;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Properties;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Future;
-import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
 
 
 @Slf4j
@@ -28,12 +31,15 @@ public class EndlessConsumer implements Runnable
   private final String topic;
   private final String autoOffsetReset;
 
-  private AtomicBoolean running = new AtomicBoolean();
+  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 Future<?> future = null;
 
-  private final Map<Integer, Map<String, Integer>> seen = new HashMap<>();
+
+  private Map<Integer, Map<String, Integer>> seen;
 
 
   public EndlessConsumer(
@@ -69,20 +75,9 @@ public class EndlessConsumer implements Runnable
       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 -> seen.remove(tp.partition()));
-        }
+      consumer.subscribe(Arrays.asList(topic));
 
-        @Override
-        public void onPartitionsAssigned(Collection<TopicPartition> partitions)
-        {
-          partitions.forEach(tp -> seen.put(tp.partition(), new HashMap<>()));
-        }
-      });
+      seen = new HashMap<>();
 
       while (true)
       {
@@ -106,6 +101,10 @@ public class EndlessConsumer implements Runnable
 
           Integer partition = record.partition();
           String key = record.key() == null ? "NULL" : record.key();
+
+          if (!seen.containsKey(partition))
+            seen.put(partition, new HashMap<>());
+
           Map<String, Integer> byKey = seen.get(partition);
 
           if (!byKey.containsKey(key))
@@ -120,11 +119,12 @@ public class EndlessConsumer implements Runnable
     catch(WakeupException e)
     {
       log.info("{} - RIIING!", id);
+      shutdown();
     }
     catch(Exception e)
     {
       log.error("{} - Unexpected error: {}", id, e.toString(), e);
-      running.set(false); // Mark the instance as not running
+      shutdown(e);
     }
     finally
     {
@@ -144,6 +144,7 @@ public class EndlessConsumer implements Runnable
               key);
         }
       }
+      seen = null;
 
       log.info("{} - Consumer-Thread exiting", id);
     }
@@ -154,26 +155,62 @@ public class EndlessConsumer implements Runnable
     return seen;
   }
 
-  public synchronized void start()
+  private void shutdown()
   {
-    boolean stateChanged = running.compareAndSet(false, true);
-    if (!stateChanged)
-      throw new RuntimeException("Consumer instance " + id + " is already running!");
+    shutdown(null);
+  }
 
-    log.info("{} - Starting - consumed {} messages before", id, consumed);
-    future = executor.submit(this);
+  private void shutdown(Exception e)
+  {
+    lock.lock();
+    try
+    {
+      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();
+    }
   }
 
   public synchronized void stop() throws ExecutionException, InterruptedException
   {
-    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);
+    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();
+    }
   }
 
   @PreDestroy
@@ -188,9 +225,42 @@ public class EndlessConsumer implements Runnable
     {
       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);
     }
   }
+
+  public boolean running()
+  {
+    lock.lock();
+    try
+    {
+      return running;
+    }
+    finally
+    {
+      lock.unlock();
+    }
+  }
+
+  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();
+    }
+  }
 }