Spring Kafka - Hello

Project in Java with Spring, Gradle and Kafka to create a topic producing and consuming application.

Steps

The steps of project implementation:

Create project (in IntelliJ) with:

Java language (17);
Spring Framework (6.2.3);
Dependencies: Web, Kafka, DevTools.

Configure and run Kafka on local machine with Docker:

Create the docker-compose.yml file:

 version: '2'
services:
  zookeeper:
    image: confluentinc/cp-zookeeper:7.4.4
    environment:
      ZOOKEEPER_CLIENT_PORT: 2181
      ZOOKEEPER_TICK_TIME: 2000
    ports:
      - 22181:2181
  
  kafka:
    image: confluentinc/cp-kafka:7.4.4
    depends_on:
      - zookeeper
    ports:
      - 29092:29092
    environment:
      KAFKA_BROKER_ID: 1
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:9092,PLAINTEXT_HOST://localhost:29092
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
      KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1

In the terminal run docker-compose up;

Change application.properties to find Kafka:

spring.kafka.bootstrap-servers=localhost:29092

Create HelloProducerService class:

annotated with @Service;
with a KafkaTemplate<String, String> kafkaTemplate attribute;
with a constructor with an argument;
with a void sendMessage(String message) method;

Create HelloConsumerService class:

annotated with @Service;
with a method @KafkaListener(topics = "hello-topic", groupId = "group-1") public void receiveMessage(String message);

Create HelloController class:

annotated with @RestController and @RequestMapping("/kafka");
with a HelloProducerService service attribute;
with a constructor with one argument and annotated with @Autowired;
with a method @GetMapping("/hello/{name}") public String hello(@PathVariable("name") String name);

Test application with POSTMAN localhost:8080/kafka/hello/leo.

References

Spring for Apache Kafka - Quick Tour: https://docs.spring.io/spring-kafka/reference/quick-tour.html

Baeldung - Intro to Apache Kafka with Spring: https://www.baeldung.com/spring-kafka

Introdução à Mensageria com Spring e Kafka - Giuliana Bezerra: https://www.youtube.com/watch?v=97TF2xZgAhU | https://github.com/giuliana-bezerra/messaging-springboot

leosimoes/Java-Spring-Kafka-Hello

Spring Kafka - Hello

Steps

References