From: Kai Moritz <kai@juplo.de>
Date: Fri, 1 Apr 2022 08:10:42 +0000 (+0200)
Subject: SimpleConsumer in EndlessConsumer umbenannt
X-Git-Tag: offset-endpoint~19
X-Git-Url: https://juplo.de/gitweb/?a=commitdiff_plain;ds=sidebyside;h=95b1d2d6fd83c68aa0db3e426f173921600e44a6;p=demos%2Fkafka%2Ftraining

SimpleConsumer in EndlessConsumer umbenannt

* Ohne die Umbenennung _vor_ der Veränderung würde die Versions-Historie
  der Klasse verloren gehen!
---

diff --git a/src/main/java/de/juplo/kafka/EndlessConsumer.java b/src/main/java/de/juplo/kafka/EndlessConsumer.java
new file mode 100644
index 0000000..e4d9697
--- /dev/null
+++ b/src/main/java/de/juplo/kafka/EndlessConsumer.java
@@ -0,0 +1,131 @@
+package de.juplo.kafka;
+
+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.common.errors.WakeupException;
+import org.apache.kafka.common.serialization.StringDeserializer;
+
+import java.time.Duration;
+import java.util.Arrays;
+import java.util.Properties;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+
+
+@Slf4j
+public class SimpleConsumer
+{
+  private long consumed = 0;
+  private KafkaConsumer<String, String> consumer;
+  private Lock lock = new ReentrantLock();
+  private Condition stopped = lock.newCondition();
+
+
+  public SimpleConsumer()
+  {
+    // tag::create[]
+    Properties props = new Properties();
+    props.put("bootstrap.servers", ":9092");
+    props.put("group.id", "my-consumer"); // << Used for Offset-Commits
+    // end::create[]
+    props.put("auto.offset.reset", "earliest");
+    // tag::create[]
+    props.put("key.deserializer", StringDeserializer.class.getName());
+    props.put("value.deserializer", StringDeserializer.class.getName());
+
+    KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
+    // end::create[]
+    this.consumer = consumer;
+  }
+
+
+  public void run()
+  {
+    String id = "C";
+
+    try
+    {
+      log.info("{} - Subscribing to topic test", id);
+      consumer.subscribe(Arrays.asList("test"));
+
+      // tag::loop[]
+      while (true)
+      {
+        ConsumerRecords<String, String> records =
+            consumer.poll(Duration.ofSeconds(1));
+
+        // Do something with the data...
+        // end::loop[]
+        log.info("{} - Received {} messages", id, records.count());
+        for (ConsumerRecord<String, String> record : records)
+        {
+          consumed++;
+          log.info(
+              "{} - {}: {}/{} - {}={}",
+              id,
+              record.offset(),
+              record.topic(),
+              record.partition(),
+              record.key(),
+              record.value()
+          );
+        }
+        // tag::loop[]
+      }
+      // end::loop[]
+    }
+    catch(WakeupException e)
+    {
+      log.info("{} - RIIING!", id);
+    }
+    catch(Exception e)
+    {
+      log.error("{} - Unexpected error: {}", id, e.toString());
+    }
+    finally
+    {
+      this.lock.lock();
+      try
+      {
+        log.info("{} - Closing the KafkaConsumer", id);
+        consumer.close();
+        log.info("C - DONE!");
+        stopped.signal();
+      }
+      finally
+      {
+        this.lock.unlock();
+        log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
+      }
+    }
+  }
+
+
+  public static void main(String[] args) throws Exception
+  {
+    SimpleConsumer instance = new SimpleConsumer();
+
+    Runtime.getRuntime().addShutdownHook(new Thread(() ->
+    {
+      instance.lock.lock();
+      try
+      {
+        instance.consumer.wakeup();
+        instance.stopped.await();
+      }
+      catch (InterruptedException e)
+      {
+        log.warn("Interrrupted while waiting for the consumer to stop!", e);
+      }
+      finally
+      {
+        instance.lock.unlock();
+      }
+    }));
+
+    instance.run();
+  }
+}
diff --git a/src/main/java/de/juplo/kafka/SimpleConsumer.java b/src/main/java/de/juplo/kafka/SimpleConsumer.java
deleted file mode 100644
index e4d9697..0000000
--- a/src/main/java/de/juplo/kafka/SimpleConsumer.java
+++ /dev/null
@@ -1,131 +0,0 @@
-package de.juplo.kafka;
-
-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.common.errors.WakeupException;
-import org.apache.kafka.common.serialization.StringDeserializer;
-
-import java.time.Duration;
-import java.util.Arrays;
-import java.util.Properties;
-import java.util.concurrent.locks.Condition;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReentrantLock;
-
-
-@Slf4j
-public class SimpleConsumer
-{
-  private long consumed = 0;
-  private KafkaConsumer<String, String> consumer;
-  private Lock lock = new ReentrantLock();
-  private Condition stopped = lock.newCondition();
-
-
-  public SimpleConsumer()
-  {
-    // tag::create[]
-    Properties props = new Properties();
-    props.put("bootstrap.servers", ":9092");
-    props.put("group.id", "my-consumer"); // << Used for Offset-Commits
-    // end::create[]
-    props.put("auto.offset.reset", "earliest");
-    // tag::create[]
-    props.put("key.deserializer", StringDeserializer.class.getName());
-    props.put("value.deserializer", StringDeserializer.class.getName());
-
-    KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
-    // end::create[]
-    this.consumer = consumer;
-  }
-
-
-  public void run()
-  {
-    String id = "C";
-
-    try
-    {
-      log.info("{} - Subscribing to topic test", id);
-      consumer.subscribe(Arrays.asList("test"));
-
-      // tag::loop[]
-      while (true)
-      {
-        ConsumerRecords<String, String> records =
-            consumer.poll(Duration.ofSeconds(1));
-
-        // Do something with the data...
-        // end::loop[]
-        log.info("{} - Received {} messages", id, records.count());
-        for (ConsumerRecord<String, String> record : records)
-        {
-          consumed++;
-          log.info(
-              "{} - {}: {}/{} - {}={}",
-              id,
-              record.offset(),
-              record.topic(),
-              record.partition(),
-              record.key(),
-              record.value()
-          );
-        }
-        // tag::loop[]
-      }
-      // end::loop[]
-    }
-    catch(WakeupException e)
-    {
-      log.info("{} - RIIING!", id);
-    }
-    catch(Exception e)
-    {
-      log.error("{} - Unexpected error: {}", id, e.toString());
-    }
-    finally
-    {
-      this.lock.lock();
-      try
-      {
-        log.info("{} - Closing the KafkaConsumer", id);
-        consumer.close();
-        log.info("C - DONE!");
-        stopped.signal();
-      }
-      finally
-      {
-        this.lock.unlock();
-        log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
-      }
-    }
-  }
-
-
-  public static void main(String[] args) throws Exception
-  {
-    SimpleConsumer instance = new SimpleConsumer();
-
-    Runtime.getRuntime().addShutdownHook(new Thread(() ->
-    {
-      instance.lock.lock();
-      try
-      {
-        instance.consumer.wakeup();
-        instance.stopped.await();
-      }
-      catch (InterruptedException e)
-      {
-        log.warn("Interrrupted while waiting for the consumer to stop!", e);
-      }
-      finally
-      {
-        instance.lock.unlock();
-      }
-    }));
-
-    instance.run();
-  }
-}