+++ /dev/null
-*
-!target/*.jar
-!target/libs/*.jar
+++ /dev/null
-target/*.jar
-target/libs/*.jar
+++ /dev/null
-FROM eclipse-temurin:21-jre
-VOLUME /tmp
-COPY target/*.jar /opt/app.jar
-COPY target/libs /opt/libs
-ENTRYPOINT [ "java", "-jar", "/opt/app.jar" ]
-CMD [ "kafka:9092", "test", "my-group", "DCKR" ]
image: juplo/simple-producer:1.0-SNAPSHOT
command: kafka:9092 test producer
- consumer:
+ consumer-1:
image: juplo/simple-consumer:1.0-SNAPSHOT
- command: kafka:9092 test my-group consumer
+ command: kafka:9092 test my-group consumer-1
+
+ consumer-2:
+ image: juplo/simple-consumer:1.0-SNAPSHOT
+ command: kafka:9092 test my-group consumer-2
+
+ consumer-3:
+ image: juplo/simple-consumer:1.0-SNAPSHOT
+ command: kafka:9092 test my-group consumer-3
volumes:
zookeeper-data:
+++ /dev/null
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
- xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-
- <modelVersion>4.0.0</modelVersion>
-
- <parent>
- <groupId>org.springframework.boot</groupId>
- <artifactId>spring-boot-starter-parent</artifactId>
- <version>3.3.4</version>
- <relativePath/> <!-- lookup parent from repository -->
- </parent>
-
- <groupId>de.juplo.kafka</groupId>
- <artifactId>simple-consumer</artifactId>
- <name>Simple Consumer-Group</name>
- <description>Super Simple Consumer-Group, that is implemented as a plain Java-program</description>
- <version>1.0-SNAPSHOT</version>
-
- <properties>
- <java.version>21</java.version>
- </properties>
-
- <dependencies>
- <dependency>
- <groupId>org.apache.kafka</groupId>
- <artifactId>kafka-clients</artifactId>
- </dependency>
- <dependency>
- <groupId>org.projectlombok</groupId>
- <artifactId>lombok</artifactId>
- </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>
- <executions>
- <execution>
- <id>copy-dependencies</id>
- <phase>package</phase>
- <goals>
- <goal>copy-dependencies</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>
- </plugin>
- <plugin>
- <groupId>io.fabric8</groupId>
- <artifactId>docker-maven-plugin</artifactId>
- <version>0.45.0</version>
- <configuration>
- <images>
- <image>
- <name>juplo/%a:%v</name>
- </image>
- </images>
- </configuration>
- <executions>
- <execution>
- <id>build</id>
- <phase>package</phase>
- <goals>
- <goal>build</goal>
- </goals>
- </execution>
- </executions>
- </plugin>
- </plugins>
- </build>
-
-</project>
+++ /dev/null
-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.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
-{
- private final String id;
- private final String topic;
- private final Consumer<String, String> consumer;
-
- private volatile boolean running = false;
- private long consumed = 0;
-
- public ExampleConsumer(
- String broker,
- String topic,
- String groupId,
- String clientId)
- {
- Properties props = new Properties();
- // Konfiguration für den Consumer zusammenstellen
-
- this.id = clientId;
- this.topic = topic;
- consumer = new KafkaConsumer<>(props);
- }
-
-
- public void run()
- {
- try
- {
- log.info("{} - Subscribing to topic {}", id, topic);
- // TODO: subscribe!
- running = true;
-
- while (true)
- {
- // TODO:
- // Über consumer.poll() Nachrichten abrufen und für die
- // empfangenen Nachrichten die Methode handleRecord
- // aufrufen.
- }
- }
- catch(WakeupException e)
- {
- log.info("{} - Consumer was signaled to finish its work", id);
- }
- catch(Exception e)
- {
- log.error("{} - Unexpected error, unsubscribing!", id, e);
- }
- finally
- {
- running = false;
- log.info("{} - Closing the KafkaConsumer", id);
- consumer.close();
- log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
- }
- }
-
- private void handleRecord(
- String topic,
- Integer partition,
- Long offset,
- String key,
- String value)
- {
- consumed++;
- log.info("{} - {}: {}/{} - {}={}", id, offset, topic, partition, key, value);
- }
-
-
- public static void main(String[] args) throws Exception
- {
- String broker = ":9092";
- String topic = "test";
- String groupId = "my-group";
- String clientId = "DEV";
-
- switch (args.length)
- {
- case 4:
- clientId = args[3];
- case 3:
- groupId = args[2];
- case 2:
- topic = args[1];
- case 1:
- broker = args[0];
- }
-
-
- ExampleConsumer instance = new ExampleConsumer(broker, topic, groupId, clientId);
-
- 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.");
- }));
-
- log.info(
- "Running ExampleConsumer: broker={}, topic={}, group-id={}, client-id={}",
- broker,
- topic,
- groupId,
- clientId);
- instance.run();
- }
-}
+++ /dev/null
-<?xml version="1.0" encoding="UTF-8"?>
-<configuration>
-
- <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
- <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
- <Pattern>%d{HH:mm:ss.SSS} | %highlight(%-5level) %msg%n</Pattern>
- </encoder>
- </appender>
-
- <logger name="de.juplo" level="TRACE"/>
-
- <root level="INFO">
- <appender-ref ref="STDOUT" />
- </root>
-
-</configuration>