@Component @RequiredArgsConstructor public class JpaProductRepository implements ProductRepository private final SpringDataJpaProductRepository jpaRepository;
Elias leaned in. The PDF used a Java analogy. In a layered app, your UserService likely extended a JpaRepository . If the database went down, the service died. The business logic was held hostage by the infrastructure.
Let's outline a typical flow:
Driving Adapter (REST) → Incoming Port (Interface) → Application Service → Outgoing Port (Interface) ← Driven Adapter (JPA)
Java is well-suited for this architecture because: designing hexagonal architecture with java pdf
Notice: The core depends only on abstractions (ports), never on concrete adapters.
public record Product(String id, String name, Money price) public Product if (price.amount() <= 0) throw new IllegalArgumentException("Price must be positive"); If the database went down, the service died
He opened it, expecting dry syntax. Instead, he found a philosophy.
// 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.*; public record Product(String id, String name, Money price)
The ports define how the application interacts with the outside world.
@Component @RequiredArgsConstructor public class JpaProductRepository implements ProductRepository private final SpringDataJpaProductRepository jpaRepository;
Elias leaned in. The PDF used a Java analogy. In a layered app, your UserService likely extended a JpaRepository . If the database went down, the service died. The business logic was held hostage by the infrastructure.
Let's outline a typical flow:
Driving Adapter (REST) → Incoming Port (Interface) → Application Service → Outgoing Port (Interface) ← Driven Adapter (JPA)
Java is well-suited for this architecture because:
Notice: The core depends only on abstractions (ports), never on concrete adapters.
public record Product(String id, String name, Money price) public Product if (price.amount() <= 0) throw new IllegalArgumentException("Price must be positive");
He opened it, expecting dry syntax. Instead, he found a philosophy.
// 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.*;
The ports define how the application interacts with the outside world.