Event Driven Architectures using Apache Kafka are gaining lots of attention lately. If combining Event Notification using Kafka with traditional Request-Response, it may be necessary to implement synchronous semantics on top of asynchronous Kafka topics. Here's how to do that using Spring Kafka.
The example is split in two projects: car provides a car service, while car-client provides a rest api to display car information. The car-model contains a common type, while the kafka-request-reply-util contains higher-level abstractions on top of Spring Kafka.
A Kafka message backbone is required to run the examples. The docker-compose file provides a convenient way of running a minimal kafka cluster in docker. Start the cluster by running
docker-compose up -d.
Then start car and car-client respectively:
mvn spring-boot:run
Access the car-client on http://localhost:8089/:
curl http://localhost:8089/car/12345678901234567