In the last blog we learned how to implement kafka consumer-publisher using plain kotlin. In this blog we’ll walk through some code to implement the same using Spring. Spring makes the implementation rather simple. We need to create a configuration class and then we can add all our code there. Setting up the configuration class We need two annotations for this Configuration and EnableKafka. We can also take some time to pick the value for bootstrapAddress and topic name from application.

In this blog we’ll learn how to interact with a kafka broker using plain kotlin. Generating a kafka project. For this we’re going to generate a spring project using spring initializer. Select the dependency Spring for Apache Kafka. We are adding this dependency so later on we can start using spring for our kafka interactions. Spinning up kafka and zookeeper. Once you’ve generated your project you’ll need to spin up an instance of kafka and zookeeper.

Kafka is a distributed event logging system. It’s widely used in event event driven system as framework of choice. Events We learned about these the last time in Event Driven Systems. In kafka an event is represented by a key-value pair. A key can be null as well. Topics A topic is an ordered log A new event is appended to end of a topic. A topic is not a queue it’s a proper Log.

A system which does something on the basis of a consumed event is considered an event driven system. Event An event is defined as a “significant change in state”. for sale -> sold interviewed -> hired low battery -> charging We can build a system that performs certain operation on basis of these state changes. Any and all state changes can be considered an event. An event shouldn’t be confused with the message/data that we send with it.