1. Schritt Live-Umbau: Spring Boot

diff --git a/pom.xml b/pom.xml
index a100717..9c40eb5 100644 (file)
--- a/pom.xml
+++ b/pom.xml
@@ -22,6 +22,14 @@
   </properties>
 
   <dependencies>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-web</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-actuator</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.apache.kafka</groupId>
       <artifactId>kafka-clients</artifactId>
@@ -31,43 +39,21 @@
       <artifactId>lombok</artifactId>
       <scope>compile</scope>
     </dependency>
-    <dependency>
-      <groupId>ch.qos.logback</groupId>
-      <artifactId>logback-classic</artifactId>
-    </dependency>
   </dependencies>
 
   <build>
     <plugins>
       <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-dependency-plugin</artifactId>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
         <executions>
           <execution>
-            <id>copy-dependencies</id>
-            <phase>package</phase>
             <goals>
-              <goal>copy-dependencies</goal>
+              <goal>build-info</goal>
             </goals>
-            <configuration>
-              <outputDirectory>${project.build.directory}/libs</outputDirectory>
-            </configuration>
           </execution>
         </executions>
       </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-jar-plugin</artifactId>
-        <configuration>
-          <archive>
-            <manifest>
-              <addClasspath>true</addClasspath>
-              <classpathPrefix>libs/</classpathPrefix>
-              <mainClass>de.juplo.kafka.ExampleConsumer</mainClass>
-            </manifest>
-          </archive>
-        </configuration>
-      </plugin>
       <plugin>
         <groupId>pl.project13.maven</groupId>
         <artifactId>git-commit-id-plugin</artifactId>

diff --git a/src/main/java/de/juplo/kafka/Application.java b/src/main/java/de/juplo/kafka/Application.java
new file mode 100644 (file)
index 0000000..0069257
--- /dev/null
+++ b/src/main/java/de/juplo/kafka/Application.java
@@ -0,0 +1,14 @@
+package de.juplo.kafka;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+
+@SpringBootApplication
+public class Application
+{
+  public static void main(String[] args)
+  {
+    SpringApplication.run(Application.class, args);
+  }
+}

diff --git a/src/main/java/de/juplo/kafka/ApplicationConfiguration.java b/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
new file mode 100644 (file)
index 0000000..55c42f6
--- /dev/null
+++ b/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
@@ -0,0 +1,41 @@
+package de.juplo.kafka;
+
+import org.apache.kafka.clients.consumer.Consumer;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.common.serialization.StringDeserializer;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import java.util.Properties;
+
+
+@Configuration
+@EnableConfigurationProperties(ApplicationProperties.class)
+public class ApplicationConfiguration
+{
+  @Bean
+  public ExampleConsumer exampleConsumer(
+    Consumer<String, String> kafkaConsumer,
+    ApplicationProperties properties)
+  {
+    return
+      new ExampleConsumer(
+        properties.getClientId(),
+        properties.getTopic(),
+        kafkaConsumer);
+  }
+
+  @Bean
+  public KafkaConsumer<String, String> kafkaConsumer(ApplicationProperties properties)
+  {
+    Properties props = new Properties();
+    props.put("bootstrap.servers", properties.getBootstrapServer());
+    props.put("client.id", properties.getClientId());
+    props.put("group.id", properties.getGroupId());
+    props.put("key.deserializer", StringDeserializer.class.getName());
+    props.put("value.deserializer", StringDeserializer.class.getName());
+
+    return new KafkaConsumer<>(props);
+  }
+}

diff --git a/src/main/java/de/juplo/kafka/ApplicationProperties.java b/src/main/java/de/juplo/kafka/ApplicationProperties.java
new file mode 100644 (file)
index 0000000..c6fe30b
--- /dev/null
+++ b/src/main/java/de/juplo/kafka/ApplicationProperties.java
@@ -0,0 +1,17 @@
+package de.juplo.kafka;
+
+import lombok.Getter;
+import lombok.Setter;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+
+@ConfigurationProperties(prefix = "juplo")
+@Getter
+@Setter
+public class ApplicationProperties
+{
+  private String bootstrapServer;
+  private String groupId;
+  private String clientId;
+  private String topic;
+}

diff --git a/src/main/java/de/juplo/kafka/ExampleConsumer.java b/src/main/java/de/juplo/kafka/ExampleConsumer.java
index 865e5cb..1d9453b 100644 (file)
--- a/src/main/java/de/juplo/kafka/ExampleConsumer.java
+++ b/src/main/java/de/juplo/kafka/ExampleConsumer.java
@@ -1,54 +1,46 @@
 package de.juplo.kafka;
 
 import lombok.extern.slf4j.Slf4j;
+import org.apache.kafka.clients.consumer.Consumer;
 import org.apache.kafka.clients.consumer.ConsumerRecord;
 import org.apache.kafka.clients.consumer.ConsumerRecords;
-import org.apache.kafka.clients.consumer.Consumer;
-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;
 
 
 @Slf4j
-public class ExampleConsumer
+public class ExampleConsumer implements Runnable
 {
   private final String id;
   private final String topic;
   private final Consumer<String, String> consumer;
+  private final Thread workerThread;
 
-  private volatile boolean running = false;
   private long consumed = 0;
 
   public ExampleConsumer(
-    String broker,
+    String clientId,
     String topic,
-    String groupId,
-    String clientId)
+    Consumer<String, String> consumer)
   {
-    Properties props = new Properties();
-    props.put("bootstrap.servers", broker);
-    props.put("group.id", groupId); // ID für die Offset-Commits
-    props.put("client.id", clientId); // Nur zur Wiedererkennung
-    props.put("key.deserializer", StringDeserializer.class.getName());
-    props.put("value.deserializer", StringDeserializer.class.getName());
-
     this.id = clientId;
     this.topic = topic;
-    consumer = new KafkaConsumer<>(props);
+    this.consumer = consumer;
+
+    workerThread = new Thread(this, "ExampleConsumer Worker-Thread");
+    workerThread.start();
   }
 
 
+  @Override
   public void run()
   {
     try
     {
       log.info("{} - Subscribing to topic {}", id, topic);
       consumer.subscribe(Arrays.asList(topic));
-      running = true;
 
       while (true)
       {
@@ -77,7 +69,6 @@ public class ExampleConsumer
     }
     finally
     {
-      running = false;
       log.info("{} - Closing the KafkaConsumer", id);
       consumer.close();
       log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
@@ -94,48 +85,5 @@ public class ExampleConsumer
     consumed++;
     log.info("{} - partition={}-{}, offset={}: {}={}", id, topic, partition, offset, key, value);
   }
-
-
-  public static void main(String[] args) throws Exception
-  {
-    if (args.length != 4)
-    {
-      log.error("Four arguments required!");
-      log.error("args[0]: Broker-Address");
-      log.error("args[1]: Topic");
-      log.error("args[2]: Group-ID");
-      log.error("args[3]: Unique Client-ID");
-      System.exit(1);
-      return;
-    }
-
-
-    log.info(
-      "Running ExampleConsumer: broker={}, topic={}, group-id={}, client-id={}",
-      args[0],
-      args[1],
-      args[2],
-      args[3]);
-
-    ExampleConsumer instance = new ExampleConsumer(args[0], args[1], args[2], args[3]);
-
-    Runtime.getRuntime().addShutdownHook(new Thread(() ->
-    {
-      instance.consumer.wakeup();
-
-      while (instance.running)
-      {
-        log.info("Waiting for main-thread...");
-        try
-        {
-          Thread.sleep(1000);
-        }
-        catch (InterruptedException e) {}
-      }
-      log.info("Shutdown completed.");
-    }));
-
-    instance.run();
-  }
 }
-  
+

diff --git a/src/main/resources/application.yml b/src/main/resources/application.yml
new file mode 100644 (file)
index 0000000..6b7340b
--- /dev/null
+++ b/src/main/resources/application.yml
@@ -0,0 +1,5 @@
+juplo:
+  bootstrap-server: localhost:9092
+  group-id: my-group
+  client-id: DEV
+  topic: test