spring-boot-event-driven-patterns

Event-Driven Architecture patterns for Spring Boot using domain events, transactional listeners, and Kafka messaging. Implement Event-Driven Architecture (EDA) patterns in Spring Boot 3.x using domain events, ApplicationEventPublisher, @TransactionalEventListener , and distributed messaging with Kafka and Spring Cloud Stream. Before (Anti-Pattern): After (Event-Driven): See examples.md for complete working examples. Create immutable event classes extending a base DomainEvent class: See domain-events-design.md for patterns. Add domain events to aggregate roots, publish via ApplicationEventPublisher : See aggregate-root-patterns.md for DDD patterns. Use @TransactionalEventListener for reliable event handling: Validate: Confirm the event handler fires only after the transaction commits by checking that the database state is committed before the handler executes. See event-handling.md for handling patterns. Configure KafkaTemplate for publishing, @KafkaListener for consuming: Validate: Send a test event via KafkaTemplate and confirm it appears in the consumer logs before proceeding to production patterns.