This commit introduces a comprehensive refactoring of the messaging module to establish a fully reactive, non-blocking, and robust infrastructure for Kafka-based communication.
Features & Refinements
Reactive Publisher:
The KafkaEventPublisher has been refactored from a blocking implementation (KafkaTemplate) to a fully non-blocking, reactive one using Spring's ReactiveKafkaProducerTemplate.
The EventPublisher interface now returns reactive types (Mono, Flux) to reflect the asynchronous nature of the operations.
Reactive Consumer:
A new KafkaEventConsumer has been implemented, providing a standardized, reusable, and reactive way for services to consume events.
It encapsulates the complexity of reactor-kafka and exposes a simple receiveEvents<T>(topic) method that returns a Flux<T>.
Architectural Cleanup:
The Spring configuration has been split. The basic ProducerFactory and consumer properties reside in messaging-config, while the reactive-specific ReactiveKafkaProducerTemplate bean is now correctly located in messaging-client.
Testing
Added Kafka Integration Test: A new KafkaIntegrationTest has been created to ensure the reliability of the messaging infrastructure.
The test uses Testcontainers to spin up a real Apache Kafka broker for end-to-end validation.
Project Reactor's StepVerifier is used to test the reactive streams deterministically, avoiding flaky tests.
The test correctly manages the lifecycle of Kafka producers to ensure clean shutdown without hanging threads.
Bug Fixes
Resolved UninitializedPropertyAccessException in tests by making the KafkaConfig test-friendly.
Fixed IllegalStateException related to Testcontainers lifecycle by making the container a static resource.
Corrected compilation errors in tests related to resource cleanup by using the concrete DefaultKafkaProducerFactory type.
stefan
stefan