From: Kai Moritz <kai@juplo.de>
Date: Thu, 20 Feb 2025 17:36:13 +0000 (+0100)
Subject: `ExampleConsumer` über Generics typisiert
X-Git-Tag: consumer/spring-consumer--generics--2025-04-signal-spickzettel~1
X-Git-Url: http://juplo.de/gitweb/?a=commitdiff_plain;h=691145a372b8e9d990ee244ce441cc84bff339ef;p=demos%2Fkafka%2Ftraining

`ExampleConsumer` über Generics typisiert
---

diff --git a/README.sh b/README.sh
index b46e235..a7cbb89 100755
--- a/README.sh
+++ b/README.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-IMAGE=juplo/spring-consumer:1.1-SNAPSHOT
+IMAGE=juplo/spring-consumer:1.1-generics-SNAPSHOT
 
 if [ "$1" = "cleanup" ]
 then
diff --git a/build.gradle b/build.gradle
index a8614fd..7e70329 100644
--- a/build.gradle
+++ b/build.gradle
@@ -8,7 +8,7 @@ plugins {
 }
 
 group = 'de.juplo.kafka'
-version = '1.1-SNAPSHOT'
+version = '1.1-generics-SNAPSHOT'
 
 java {
 	toolchain {
diff --git a/docker/docker-compose.yml b/docker/docker-compose.yml
index 9984f6b..5d1fa46 100644
--- a/docker/docker-compose.yml
+++ b/docker/docker-compose.yml
@@ -140,21 +140,21 @@ services:
     command: kafka:9092 test producer
 
   consumer:
-    image: juplo/spring-consumer:1.1-SNAPSHOT
+    image: juplo/spring-consumer:1.1-generics-SNAPSHOT
     environment:
       juplo.bootstrap-server: kafka:9092
       juplo.client-id: consumer
       juplo.consumer.topic: test
 
   peter:
-    image: juplo/spring-consumer:1.1-SNAPSHOT
+    image: juplo/spring-consumer:1.1-generics-SNAPSHOT
     environment:
       juplo.bootstrap-server: kafka:9092
       juplo.client-id: peter
       juplo.consumer.topic: test
 
   ute:
-    image: juplo/spring-consumer:1.1-SNAPSHOT
+    image: juplo/spring-consumer:1.1-generics-SNAPSHOT
     environment:
       juplo.bootstrap-server: kafka:9092
       juplo.client-id: ute
diff --git a/pom.xml b/pom.xml
index dd96d00..88730f1 100644
--- a/pom.xml
+++ b/pom.xml
@@ -15,7 +15,7 @@
   <artifactId>spring-consumer</artifactId>
   <name>Spring Consumer</name>
   <description>Super Simple Consumer-Group, that is implemented as Spring-Boot application and configured by Spring Kafka</description>
-  <version>1.1-SNAPSHOT</version>
+  <version>1.1-generics-SNAPSHOT</version>
 
   <properties>
     <java.version>21</java.version>
diff --git a/src/main/java/de/juplo/kafka/ApplicationConfiguration.java b/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
index ea6b64e..c525b11 100644
--- a/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
+++ b/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
@@ -16,13 +16,13 @@ import java.util.Properties;
 public class ApplicationConfiguration
 {
   @Bean
-  public ExampleConsumer exampleConsumer(
+  public ExampleConsumer<String, String> exampleConsumer(
     Consumer<String, String> kafkaConsumer,
     ApplicationProperties properties,
     ConfigurableApplicationContext applicationContext)
   {
     return
-      new ExampleConsumer(
+      new ExampleConsumer<>(
         properties.getClientId(),
         properties.getConsumerProperties().getTopic(),
         kafkaConsumer,
diff --git a/src/main/java/de/juplo/kafka/ExampleConsumer.java b/src/main/java/de/juplo/kafka/ExampleConsumer.java
index 1f5a570..101abd1 100644
--- a/src/main/java/de/juplo/kafka/ExampleConsumer.java
+++ b/src/main/java/de/juplo/kafka/ExampleConsumer.java
@@ -11,11 +11,11 @@ import java.util.Arrays;
 
 
 @Slf4j
-public class ExampleConsumer implements Runnable
+public class ExampleConsumer<K, V> implements Runnable
 {
   private final String id;
   private final String topic;
-  private final Consumer<String, String> consumer;
+  private final Consumer<K, V> consumer;
   private final Thread workerThread;
   private final Runnable closeCallback;
 
@@ -25,7 +25,7 @@ public class ExampleConsumer implements Runnable
   public ExampleConsumer(
     String clientId,
     String topic,
-    Consumer<String, String> consumer,
+    Consumer<K, V> consumer,
     Runnable closeCallback)
   {
     this.id = clientId;
@@ -49,10 +49,10 @@ public class ExampleConsumer implements Runnable
 
       while (true)
       {
-        ConsumerRecords<String, String> records = consumer.poll(Duration.ofSeconds(1));
+        ConsumerRecords<K, V> records = consumer.poll(Duration.ofSeconds(1));
 
         log.info("{} - Received {} messages", id, records.count());
-        for (ConsumerRecord<String, String> record : records)
+        for (ConsumerRecord<K, V> record : records)
         {
           handleRecord(
             record.topic(),
@@ -86,8 +86,8 @@ public class ExampleConsumer implements Runnable
     String topic,
     Integer partition,
     Long offset,
-    String key,
-    String value)
+    K key,
+    V value)
   {
     consumed++;
     log.info("{} - partition={}-{}, offset={}: {}={}", id, topic, partition, offset, key, value);