Designing Hexagonal Architecture With Java Pdf | Fixed

// Port interface public interface UserRepository User getUser(Long id);

Driving Adapter (REST) → Incoming Port (Interface) → Application Service → Outgoing Port (Interface) ← Driven Adapter (JPA) designing hexagonal architecture with java pdf

@SpringBootTest @Testcontainers class JpaProductRepositoryTest @Container static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:15"); @Test void shouldSaveAndRetrieve() // ... real database test // adapters/web/ProductController

The "heart" of the application containing business rules, entities, and use cases. It is written in Plain Old Java Objects (POJOs) and must remain free of framework-specific annotations like JPA or Spring. he needed to encapsulate it.

// adapters/web/ProductController.java package com.example.adapters.web; import com.example.application.port.in.CreateProductUseCase; import com.example.application.port.in.CreateProductUseCase.CreateProductCommand; import com.example.domain.model.Product; import lombok.RequiredArgsConstructor; import org.springframework.web.bind.annotation.*;

Elias imagined applying this to "The Blob." He could peel away the database, wrap the core logic in a hexagon, and plug in a new database adapter without breaking the business rules. He didn't need to rewrite the app; he needed to encapsulate it.