kafka-streams-flatmap

Kafka Streams FlatMap

This module demonstrates the following:

• The usage of the Kafka Streams DSL, including flatMap() and peek().
• Unit testing using Topology Test Driver.

In this module, records of type <String, KafkaPerson> are streamed from a topic named PERSON_TOPIC. The following tasks are performed:

1. Map the KafkaPerson value to extract both the first name and last name.
2. Convert the respective keys to uppercase for the first name and last name.
3. Flatten the resulting key-value pairs.
4. Write the flattened key-value pairs into a new topic named PERSON_FLATMAP_TOPIC.

Requirements

To compile and run this demo, you will need the following:

• Java 21
• Maven
• Docker

Running the Application

To run the application manually, please follow the steps below:

• Start a Confluent Platform in a Docker environment.
• Produce records of type <String, KafkaPerson> to a topic named PERSON_TOPIC. You can use the producer person to do this.
• Start the Kafka Streams.

To run the application in Docker, please use the following command:

docker-compose up -d

This command will start the following services in Docker:

• 1 Kafka broker KRaft
• 1 Schema registry
• 1 Control Center
• 1 producer Person
• 1 Kafka Streams Flatmap