#!/bin/bash
-IMAGE=juplo/spring-consumer:1.1-SNAPSHOT
+IMAGE=juplo/supersimple-consumer:1.0-SNAPSHOT
if [ "$1" = "cleanup" ]
then
}
group = 'de.juplo.kafka'
-version = '1.1-SNAPSHOT'
+version = '1.0-SNAPSHOT'
java {
toolchain {
}
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'
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'
juplo.producer.throttle-ms: 100
consumer:
- image: juplo/spring-consumer:1.1-SNAPSHOT
+ image: juplo/supersimple-consumer:1.0-SNAPSHOT
environment:
- juplo.bootstrap-server: kafka:9092
- juplo.client-id: consumer
- juplo.consumer.topic: test
+ spring.kafka.bootstrap-servers: kafka:9092
+ spring.kafka.client-id: consumer
peter:
- image: juplo/spring-consumer:1.1-SNAPSHOT
+ image: juplo/supersimple-peter:1.0-SNAPSHOT
environment:
- juplo.bootstrap-server: kafka:9092
- juplo.client-id: peter
- juplo.consumer.topic: test
+ spring.kafka.bootstrap-servers: kafka:9092
+ spring.kafka.client-id: peter
ute:
- image: juplo/spring-consumer:1.1-SNAPSHOT
+ image: juplo/supersimple-ute:1.0-SNAPSHOT
environment:
- juplo.bootstrap-server: kafka:9092
- juplo.client-id: ute
- juplo.consumer.topic: test
+ spring.kafka.bootstrap-servers: kafka:9092
+ spring.kafka.client-id: ute
volumes:
zookeeper-data:
</parent>
<groupId>de.juplo.kafka</groupId>
- <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>
+ <artifactId>supersimple-consumer</artifactId>
+ <name>Supersimple Consumer-Group</name>
+ <description>Most minimal Consumer-Group ever!</description>
+ <version>1.0-SNAPSHOT</version>
<properties>
<java.version>21</java.version>
<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>
<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>
-rootProject.name = 'spring-consumer'
+rootProject.name = 'supersimple-consumer'
+++ /dev/null
-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);
- }
-}
+++ /dev/null
-package de.juplo.kafka;
-
-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.boot.context.properties.EnableConfigurationProperties;
-import org.springframework.context.ConfigurableApplicationContext;
-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<String, String> exampleConsumer(
- Consumer<String, String> kafkaConsumer,
- ApplicationProperties properties,
- ConfigurableApplicationContext applicationContext)
- {
- return
- new ExampleConsumer<>(
- properties.getClientId(),
- properties.getConsumerProperties().getTopic(),
- kafkaConsumer,
- () -> applicationContext.close());
- }
-
- @Bean(destroyMethod = "")
- 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.getConsumerProperties().getGroupId());
- if (properties.getConsumerProperties().getAutoOffsetReset() != null)
- {
- props.put("auto.offset.reset", properties.getConsumerProperties().getAutoOffsetReset().name());
- }
- if (properties.getConsumerProperties().getAutoCommitInterval() != null)
- {
- props.put("auto.commit.interval", properties.getConsumerProperties().getAutoCommitInterval());
- }
- 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());
-
- return new KafkaConsumer<>(props);
- }
-}
+++ /dev/null
-package de.juplo.kafka;
-
-import jakarta.validation.constraints.NotEmpty;
-import jakarta.validation.constraints.NotNull;
-import lombok.Getter;
-import lombok.Setter;
-import org.springframework.boot.context.properties.ConfigurationProperties;
-import org.springframework.validation.annotation.Validated;
-
-import java.time.Duration;
-
-
-@ConfigurationProperties(prefix = "juplo")
-@Validated
-@Getter
-@Setter
-public class ApplicationProperties
-{
- @NotNull
- @NotEmpty
- private String bootstrapServer;
- @NotNull
- @NotEmpty
- private String clientId;
-
- @NotNull
- private ConsumerProperties consumer;
-
-
- public ConsumerProperties getConsumerProperties()
- {
- return consumer;
- }
-
-
- @Validated
- @Getter
- @Setter
- static class ConsumerProperties
- {
- @NotNull
- @NotEmpty
- private String groupId;
- @NotNull
- @NotEmpty
- private String topic;
- private OffsetReset autoOffsetReset;
- private Duration autoCommitInterval;
-
- enum OffsetReset { latest, earliest, none }
- }
-}
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.common.errors.WakeupException;
-
-import java.time.Duration;
-import java.util.Arrays;
-
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.kafka.annotation.KafkaListener;
+// tag::supersimple[]
+@SpringBootApplication
@Slf4j
-public class ExampleConsumer<K, V> implements Runnable
+public class ExampleConsumer
{
- private final String id;
- private final String topic;
- private final Consumer<K, V> consumer;
- private final Thread workerThread;
- private final Runnable closeCallback;
-
- private volatile boolean running = false;
- private long consumed = 0;
-
-
- public ExampleConsumer(
- String clientId,
- String topic,
- Consumer<K, V> consumer,
- Runnable closeCallback)
+ @KafkaListener(id = "supersimple", topics = "test")
+ public void recieve(String message)
{
- this.id = clientId;
- this.topic = topic;
- this.consumer = consumer;
-
- workerThread = new Thread(this, "ExampleConsumer Worker-Thread");
- workerThread.start();
-
- this.closeCallback = closeCallback;
+ log.info("Recieved message: {}", message);
}
-
- @Override
- public void run()
- {
- try
- {
- log.info("{} - Subscribing to topic {}", id, topic);
- consumer.subscribe(Arrays.asList(topic));
- running = true;
-
- while (running)
- {
- ConsumerRecords<K, V> records = consumer.poll(Duration.ofSeconds(1));
-
- log.info("{} - Received {} messages", id, records.count());
- for (ConsumerRecord<K, V> record : records)
- {
- handleRecord(
- record.topic(),
- record.partition(),
- record.offset(),
- record.key(),
- record.value());
- }
- }
- }
- catch(WakeupException e)
- {
- log.info("{} - Consumer was signaled to finish its work", id);
- }
- catch(Exception e)
- {
- log.error("{} - Unexpected error, unsubscribing!", id, e);
- consumer.unsubscribe();
- log.info("{} - Triggering exit of application!", id);
- new Thread(closeCallback).start();
- }
- finally
- {
- 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,
- K key,
- V value)
- {
- consumed++;
- log.info("{} - partition={}-{}, offset={}: {}={}", id, topic, partition, offset, key, value);
- }
-
-
- public void shutdown() throws InterruptedException
+ public static void main(String[] args)
{
- log.info("{} joining the worker-thread...", id);
- running = false;
- consumer.wakeup();
- workerThread.join();
+ SpringApplication.run(ExampleConsumer.class, args);
}
}
+// end::supersimple[]
-juplo:
- bootstrap-server: :9092
- client-id: DEV
- consumer:
- group-id: my-group
- topic: test
- auto-offset-reset: earliest
- auto-commit-interval: 5s
+spring:
+ kafka:
+ bootstrap-servers: :9092
management:
endpoint:
shutdown:
enabled: true
java:
enabled: true
-info:
- kafka:
- bootstrap-server: ${juplo.bootstrap-server}
- client-id: ${juplo.client-id}
- consumer:
- group-id: ${juplo.consumer.group-id}
- topic: ${juplo.consumer.topic}
- auto-offset-reset: ${juplo.consumer.auto-offset-reset}
- auto-commit-interval: ${juplo.consumer.auto-commit-interval}
logging:
level:
root: INFO
@SpringBootTest(
properties = {
- "juplo.bootstrap-server=${spring.embedded.kafka.brokers}",
- "juplo.consumer.topic=" + TOPIC })
+ "spring.kafka.consumer.auto-offset-reset=earliest",
+ })
@AutoConfigureMockMvc
@EmbeddedKafka(topics = TOPIC, partitions = PARTITIONS)
public class ApplicationTests
{
- static final String TOPIC = "FOO";
+ static final String TOPIC = "test";
static final int PARTITIONS = 10;
@Autowired