From: Kai Moritz <kai@juplo.de>
Date: Wed, 2 Nov 2022 17:42:34 +0000 (+0100)
Subject: WIP
X-Git-Tag: simple-consumer--json-DEPRECATED~26
X-Git-Url: http://juplo.de/gitweb/?a=commitdiff_plain;h=d58ed9de440e56ecf906b26803591290b1c4f60d;p=demos%2Fkafka%2Ftraining

WIP
---

diff --git a/src/main/java/de/juplo/kafka/Application.java b/src/main/java/de/juplo/kafka/Application.java
index 94224e1..ab357c7 100644
--- a/src/main/java/de/juplo/kafka/Application.java
+++ b/src/main/java/de/juplo/kafka/Application.java
@@ -11,30 +11,39 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.kafka.core.ConsumerFactory;
 
 import javax.annotation.PreDestroy;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Future;
 
 
 @SpringBootApplication
 @Slf4j
 public class Application implements ApplicationRunner
 {
+  @Autowired
+  ExecutorService executorService;
   @Autowired
   Consumer<String, Message> consumer;
   @Autowired
   SimpleConsumer simpleConsumer;
 
+  Future<?> consumerJob;
 
   @Override
   public void run(ApplicationArguments args) throws Exception
   {
-    log.info("Starting EndlessConsumer");
-    simpleConsumer.start();
+    log.info("Starting SimpleConsumer");
+    consumerJob = executorService.submit(simpleConsumer);
   }
 
   @PreDestroy
-  public void shutdown()
+  public void shutdown() throws ExecutionException, InterruptedException
   {
-    log.info("Signaling the consumer to quit its work");
+    log.info("Signaling SimpleConsumer to quit its work");
     consumer.wakeup();
+    log.info("Waiting for SimpleConsumer to finish its work");
+    consumerJob.get();
+    log.info("SimpleConsumer finished its work");
   }
 
   @Bean(destroyMethod = "close")
diff --git a/src/main/java/de/juplo/kafka/EndlessConsumer.java b/src/main/java/de/juplo/kafka/EndlessConsumer.java
deleted file mode 100644
index ba8eb27..0000000
--- a/src/main/java/de/juplo/kafka/EndlessConsumer.java
+++ /dev/null
@@ -1,214 +0,0 @@
-package de.juplo.kafka;
-
-import lombok.RequiredArgsConstructor;
-import lombok.extern.slf4j.Slf4j;
-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.springframework.stereotype.Component;
-
-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;
-
-
-@Component
-@Slf4j
-@RequiredArgsConstructor
-public class EndlessConsumer implements Runnable
-{
-  private final ExecutorService executor;
-  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 final Lock lock = new ReentrantLock();
-  private final Condition condition = lock.newCondition();
-  private boolean running = false;
-  private Exception exception;
-  private long consumed = 0;
-
-
-
-  @Override
-  public void run()
-  {
-    try
-    {
-      log.info("{} - Subscribing to topic {}", id, topic);
-      consumer.subscribe(Arrays.asList(topic), rebalanceListener);
-
-      while (true)
-      {
-        ConsumerRecords<K, V> records =
-            consumer.poll(Duration.ofSeconds(1));
-
-        // Do something with the data...
-        log.info("{} - Received {} messages", id, records.count());
-        for (ConsumerRecord<K, V> record : records)
-        {
-          log.info(
-              "{} - {}: {}/{} - {}={}",
-              id,
-              record.offset(),
-              record.topic(),
-              record.partition(),
-              record.key(),
-              record.value()
-          );
-
-          recordHandler.accept(record);
-
-          consumed++;
-        }
-      }
-    }
-    catch(WakeupException e)
-    {
-      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);
-      shutdown(e);
-    }
-    finally
-    {
-      log.info("{} - Consumer-Thread exiting", id);
-    }
-  }
-
-  private void shutdown()
-  {
-    shutdown(null);
-  }
-
-  private void shutdown(Exception e)
-  {
-    lock.lock();
-    try
-    {
-      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
-    {
-      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 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();
-    }
-  }
-
-  @PreDestroy
-  public void destroy() throws ExecutionException, InterruptedException
-  {
-    log.info("{} - Destroy!", id);
-    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();
-    }
-  }
-}
diff --git a/src/main/java/de/juplo/kafka/SimpleConsumer.java b/src/main/java/de/juplo/kafka/SimpleConsumer.java
index 0d371f4..040e24b 100644
--- a/src/main/java/de/juplo/kafka/SimpleConsumer.java
+++ b/src/main/java/de/juplo/kafka/SimpleConsumer.java
@@ -72,9 +72,4 @@ public class SimpleConsumer implements Runnable
       log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
     }
   }
-
-  public void start()
-  {
-    executor.submit(this);
-  }
 }