We can send messages using the KafkaTemplate class: The send API returns a ListenableFuture object. So let's add it to our pom.xml: Instead of using the latest version of Jackson, it's recommended to use the version which is added to the pom.xml of spring-kafka. The high level overview of all the articles on the site. Let's look at a simple bean class, which we will send as messages: In this example, we will use JsonSerializer. Steps we will follow: Create Spring boot application with Kafka dependencies Configure kafka broker instance in application.yaml Use KafkaTemplate to send messages to topic Use @KafkaListener […] @EnableKafka annotation is required on the configuration class to enable detection of @KafkaListener annotation on spring managed beans: Multiple listeners can be implemented for a topic, each with a different group Id. You can take a look at this article how the problem is solved using Kafka for Spring boot microservices – here. So far we have only covered sending and receiving Strings as messages. The guides on building REST APIs with Spring. It is fast, scalable and distrib Complete source code for this article can be found over on GitHub. Learn to create a spring boot application which is able to connect a given Apache Kafka broker instance. The thread will wait for the result, but it will slow down the producer. Create Spring boot application with Kafka dependencies, We are creating a maven based Spring boot application, so your machine should have minimum. We can do this through a callback: For consuming messages, we need to configure a ConsumerFactory and a KafkaListenerContainerFactory. Spring Boot - Apache Kafka - Apache Kafka is an open source project used to publish and subscribe the messages based on the fault-tolerant messaging system. THE unique Spring Security education if you’re working with Java today. Then we need a KafkaTemplate which wraps a Producer instance and provides convenience methods for sending messages to Kafka topics. Kafka + Spring Boot – Event Driven: When we have multiple microservices with different data sources, data consistency among the microservices is a big challenge. All Rights Reserved. This article assumes that the server is started using the default configuration and no server ports are changed. That’s the only way we can improve. Let us know if you liked the post. Configuring multiple kafka consumers and producers, Configuring each consumer to listen to separate topic, Configuring each producer publish to separate topic, Spring Kafka will automatically add topics for all beans of type, By default, it uses default values of the partition and the replication factor as, If you are not using Spring boot then make sure to create. Finally, we need to write a listener to consume Greeting messages: In this article, we covered the basics of Spring support for Apache Kafka. Spring Kafka brings the simple and typical Spring template programming model with a KafkaTemplate and Message-driven POJOs via @KafkaListener annotation. Have a look at a practical example using Kafka connectors. From no experience to actually building stuff​. Apache Kafkais a distributed and fault-tolerant stream processing system. Spring Kafka brings the simple and typical Spring template programming model with a KafkaTemplate and Message-driven POJOs via @KafkaListenerannotation. In this article, we'll cover Spring support for Kafka and the level of abstractions it provides over native Kafka Java client APIs. However, for a topic with multiple partitions, a @KafkaListener can explicitly subscribe to a particular partition of a topic with an initial offset: Since the initialOffset has been sent to 0 in this listener, all the previously consumed messages from partitions 0 and three will be re-consumed every time this listener is initialized. Before executing the code, please make sure that Kafka server is running and the topics are created manually. Learn how to process stream data with Flink and Kafka.