spring-hexagonal-patterns

Hexagonal architecture in Spring Boot separates domain, application, and infrastructure concerns using ports and adapters. This pattern enforces clear boundaries around explicit domain models, enabling easier testing, API design, and maintenance across multi-module structures.

Organize Spring Boot modules into xxx-domain, xxx-app-api, and xxx-infra layers to implement ports and adapters. Wire adapters accordingly to enforce boundaries between the explicit domain models, application logic, and infrastructure components.

Yes, you can enforce clean boundaries in Spring by applying hexagonal architecture principles to multi-module projects. This approach isolates explicit domain models and infrastructure concerns using ports and adapters, ensuring strict separation and improved testability.

The best way to handle exceptions and validation in hexagonal architecture is to align them with your ports and adapters boundaries. This ensures error handling and validation logic remain within the domain and application layers, maintaining clean separation from infrastructure.

You should use hexagonal architecture for Spring multi-module applications when you need to resolve architectural complexity. It is ideal when you require strict ports and adapters boundaries, explicit domain modeling, and enhanced testability across domain, application, and infrastructure layers.