Version des `spring-consumer`, der JSON-Nachrichten erwartet

* Fachliche Behandlung der unterschiedlichen Nachrichten-Typen ergänzt

diff --git a/README.sh b/README.sh
index b46e235..7152ec9 100755 (executable)
--- 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-json-SNAPSHOT
 
 if [ "$1" = "cleanup" ]
 then

diff --git a/build.gradle b/build.gradle
index a8614fd..3ddca4b 100644 (file)
--- a/build.gradle
+++ b/build.gradle
@@ -8,7 +8,7 @@ plugins {
 }
 
 group = 'de.juplo.kafka'
-version = '1.1-SNAPSHOT'
+version = '1.1-json-SNAPSHOT'
 
 java {
        toolchain {
@@ -27,7 +27,7 @@ repositories {
 }
 
 dependencies {
-       implementation 'org.apache.kafka:kafka-clients'
+       implementation 'org.springframework.kafka:spring-kafka'
        implementation 'org.springframework.boot:spring-boot-starter-actuator'
        implementation 'org.springframework.boot:spring-boot-starter-validation'
        implementation 'org.springframework.boot:spring-boot-starter-web'
@@ -36,7 +36,6 @@ dependencies {
        annotationProcessor 'org.springframework.boot:spring-boot-configuration-processor'
        annotationProcessor 'org.projectlombok:lombok'
        testImplementation 'org.springframework.boot:spring-boot-starter-test'
-       testImplementation 'org.springframework.kafka:spring-kafka'
        testImplementation 'org.springframework.kafka:spring-kafka-test'
        testCompileOnly 'org.projectlombok:lombok'
        testAnnotationProcessor 'org.projectlombok:lombok'

diff --git a/docker/docker-compose.yml b/docker/docker-compose.yml
index 4fa2ead..9fb105f 100644 (file)
--- a/docker/docker-compose.yml
+++ b/docker/docker-compose.yml
@@ -136,7 +136,7 @@ services:
       - kafka-3
 
   producer:
-    image: juplo/spring-producer:1.0-SNAPSHOT
+    image: juplo/spring-producer:1.0-json-SNAPSHOT
     environment:
       juplo.bootstrap-server: kafka:9092
       juplo.client-id: producer
@@ -145,21 +145,21 @@ services:
       juplo.producer.throttle-ms: 100
 
   consumer:
-    image: juplo/spring-consumer:1.1-SNAPSHOT
+    image: juplo/spring-consumer:1.1-json-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-json-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-json-SNAPSHOT
     environment:
       juplo.bootstrap-server: kafka:9092
       juplo.client-id: ute

diff --git a/pom.xml b/pom.xml
index dd96d00..8dd99a5 100644 (file)
--- 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-json-SNAPSHOT</version>
 
   <properties>
     <java.version>21</java.version>
@@ -40,8 +40,8 @@
       <artifactId>spring-boot-starter-validation</artifactId>
     </dependency>
     <dependency>
-      <groupId>org.apache.kafka</groupId>
-      <artifactId>kafka-clients</artifactId>
+      <groupId>org.springframework.kafka</groupId>
+      <artifactId>spring-kafka</artifactId>
     </dependency>
     <dependency>
       <groupId>org.projectlombok</groupId>
@@ -53,11 +53,6 @@
       <artifactId>spring-boot-starter-test</artifactId>
       <scope>test</scope>
     </dependency>
-    <dependency>
-      <groupId>org.springframework.kafka</groupId>
-      <artifactId>spring-kafka</artifactId>
-      <scope>test</scope>
-    </dependency>
     <dependency>
       <groupId>org.springframework.kafka</groupId>
       <artifactId>spring-kafka-test</artifactId>

diff --git a/src/main/java/de/juplo/kafka/ApplicationConfiguration.java b/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
index b98c401..33022bf 100644 (file)
--- a/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
+++ b/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
@@ -4,6 +4,7 @@ import org.apache.kafka.clients.consumer.Consumer;
 import org.apache.kafka.clients.consumer.KafkaConsumer;
 import org.apache.kafka.clients.consumer.StickyAssignor;
 import org.apache.kafka.common.serialization.StringDeserializer;
+import org.springframework.kafka.support.serializer.JsonDeserializer;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
@@ -18,7 +19,7 @@ public class ApplicationConfiguration
 {
   @Bean
   public ExampleConsumer exampleConsumer(
-    Consumer<String, String> kafkaConsumer,
+    Consumer<String, Message> kafkaConsumer,
     ApplicationProperties properties,
     ConfigurableApplicationContext applicationContext)
   {
@@ -31,7 +32,7 @@ public class ApplicationConfiguration
   }
 
   @Bean(destroyMethod = "")
-  public KafkaConsumer<String, String> kafkaConsumer(ApplicationProperties properties)
+  public KafkaConsumer<String, Message> kafkaConsumer(ApplicationProperties properties)
   {
     Properties props = new Properties();
     props.put("bootstrap.servers", properties.getBootstrapServer());
@@ -48,7 +49,8 @@ public class ApplicationConfiguration
     props.put("metadata.maxage.ms", 5000); //  5 Sekunden
     props.put("partition.assignment.strategy", StickyAssignor.class.getName());
     props.put("key.deserializer", StringDeserializer.class.getName());
-    props.put("value.deserializer", StringDeserializer.class.getName());
+    props.put("value.deserializer", JsonDeserializer.class.getName());
+    props.put("spring.json.type.mapping", "ADD:de.juplo.kafka.MessageAddNumber,CALC:de.juplo.kafka.MessageCalculateSum");
 
     return new KafkaConsumer<>(props);
   }

diff --git a/src/main/java/de/juplo/kafka/ExampleConsumer.java b/src/main/java/de/juplo/kafka/ExampleConsumer.java
index 1f5a570..a03fece 100644 (file)
--- a/src/main/java/de/juplo/kafka/ExampleConsumer.java
+++ b/src/main/java/de/juplo/kafka/ExampleConsumer.java
@@ -15,7 +15,7 @@ public class ExampleConsumer implements Runnable
 {
   private final String id;
   private final String topic;
-  private final Consumer<String, String> consumer;
+  private final Consumer<String, Message> 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<String, Message> 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<String, Message> records = consumer.poll(Duration.ofSeconds(1));
 
         log.info("{} - Received {} messages", id, records.count());
-        for (ConsumerRecord<String, String> record : records)
+        for (ConsumerRecord<String, Message> record : records)
         {
           handleRecord(
             record.topic(),
@@ -87,12 +87,27 @@ public class ExampleConsumer implements Runnable
     Integer partition,
     Long offset,
     String key,
-    String value)
+    Message value)
   {
     consumed++;
     log.info("{} - partition={}-{}, offset={}: {}={}", id, topic, partition, offset, key, value);
+    switch (value.getType())
+    {
+      case ADD  -> addNumber((MessageAddNumber)value);
+      case CALC -> calcSum((MessageCalculateSum)value);
+      default   -> log.error("{} - Ignoring message of unknown typ {}", id, value.getType());
+    }
   }
 
+  private void addNumber(MessageAddNumber addNumber)
+  {
+    log.info("{} - Adding number {}", id, addNumber.getNext());
+  }
+
+  private void calcSum(MessageCalculateSum calculateSum)
+  {
+    log.info("{} - Calculating sum", id);
+  }
 
   public void shutdown() throws InterruptedException
   {

diff --git a/src/main/java/de/juplo/kafka/Message.java b/src/main/java/de/juplo/kafka/Message.java
new file mode 100644 (file)
index 0000000..e4999b7
--- /dev/null
+++ b/src/main/java/de/juplo/kafka/Message.java
@@ -0,0 +1,9 @@
+package de.juplo.kafka;
+
+
+public abstract class Message
+{
+  public enum Type {ADD, CALC}
+
+  public abstract Type getType();
+}

diff --git a/src/main/java/de/juplo/kafka/MessageAddNumber.java b/src/main/java/de/juplo/kafka/MessageAddNumber.java
new file mode 100644 (file)
index 0000000..c024b65
--- /dev/null
+++ b/src/main/java/de/juplo/kafka/MessageAddNumber.java
@@ -0,0 +1,19 @@
+package de.juplo.kafka;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import lombok.Data;
+
+
+@Data
+@JsonIgnoreProperties(ignoreUnknown = true)
+public class MessageAddNumber extends Message
+{
+  private Integer next;
+
+
+  @Override
+  public Type getType()
+  {
+    return Type.ADD;
+  }
+}

diff --git a/src/main/java/de/juplo/kafka/MessageCalculateSum.java b/src/main/java/de/juplo/kafka/MessageCalculateSum.java
new file mode 100644 (file)
index 0000000..afc5a39
--- /dev/null
+++ b/src/main/java/de/juplo/kafka/MessageCalculateSum.java
@@ -0,0 +1,16 @@
+package de.juplo.kafka;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import lombok.Data;
+
+
+@Data
+@JsonIgnoreProperties(ignoreUnknown = true)
+public class MessageCalculateSum extends Message
+{
+  @Override
+  public Type getType()
+  {
+    return Type.CALC;
+  }
+}

diff --git a/src/test/java/de/juplo/kafka/MessageTest.java b/src/test/java/de/juplo/kafka/MessageTest.java
new file mode 100644 (file)
index 0000000..82116f4
--- /dev/null
+++ b/src/test/java/de/juplo/kafka/MessageTest.java
@@ -0,0 +1,29 @@
+package de.juplo.kafka;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+
+public class MessageTest
+{
+  ObjectMapper mapper = new ObjectMapper();
+
+  @Test
+  @DisplayName("Deserialize a MessageAddNumber message")
+  public void testDeserializeMessageAddNumber()
+  {
+    Assertions.assertDoesNotThrow(() -> mapper.readValue("{\"next\":42}", MessageAddNumber.class));
+    Assertions.assertDoesNotThrow(() -> mapper.readValue("{\"number\":666,\"next\":42}", MessageAddNumber.class));
+  }
+
+  @Test
+  @DisplayName("Deserialize a MessageCalculateSum message")
+  public void testDeserializeMessageCalculateSum() throws JsonProcessingException
+  {
+    Assertions.assertDoesNotThrow(() -> mapper.readValue("{}", MessageCalculateSum.class));
+    Assertions.assertDoesNotThrow(() -> mapper.readValue("{\"number\":666}", MessageCalculateSum.class));
+  }
+}