kafka-streams-select-key

Kafka Streams Select Key

This module demonstrates the following:

• The use of the Processor API, including selectKey() and peek().
• Unit testing using Topology Test Driver.

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

1. Selects the last name of each record as the new key.
2. Writes the resulting records into a new topic named USER_SELECT_KEY_TOPIC.

Prerequisites

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

• Java 21
• Maven
• Docker

Running the Application

To run the application manually:

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

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

docker-compose up -d

This command will start the following services in Docker:

• 1 Kafka broker (KRaft mode)
• 1 Schema registry
• 1 Control Center
• 1 producer User
• 1 Kafka Streams Select Key