hexagonal-architecture-layers-java

Hexagonal architecture isolates domain logic by structuring Java applications into pure domain, application, and infrastructure layers, ensuring the core domain remains free of framework-specific dependencies.

Ports and adapters structure Java services by defining application ports for use cases and wiring infrastructure adapters for external technologies, enforcing strict dependency direction and clear module boundaries.

Refactoring monolithic Spring applications to clean architecture isolates business logic into pure domain models, making components easier to test and allowing infrastructure adapters like databases to be swapped.

Hexagonal architecture enforces dependency direction by making infrastructure adapters depend on application ports, ensuring multiple adapters like REST and messaging never pollute the core domain logic.

Hexagonal architecture is needed when strict separation of concerns is required to isolate domain logic from infrastructure frameworks, increasing testability and enabling multiple adapter implementations.

Domain-driven design requires pure domain models free of framework-specific annotations to enforce clean architecture principles, ensuring domain logic remains isolated and testable within the application layer.