Have you had experience working with architecture that uses hexagonal components or structures?

Hexagonal Architecture, also known as Ports and Adapters, is a software design approach that separates business logic from external systems (interfaces, databases, UI).

In my experience with Java, I used this approach to create modular and easily testable applications. The main idea:

• The core of the application contains the business logic.
• Around it are ports — interfaces through which the core interacts with the outside world.
• Adapters implement these ports and provide connections to databases, web services, user interfaces.

Example:

// Port
public interface UserRepository {
    User findById(String id);
}

// Core
public class UserService {
    private final UserRepository userRepository;

    public UserService(UserRepository userRepository) {
        this.userRepository = userRepository;
    }

    public User getUser(String id) {
        return userRepository.findById(id);
    }
}

// Adapter
public class UserRepositoryImpl implements UserRepository {
    // Implementation of database access
}

This approach improves testability and maintainability of the code, as the business logic does not depend on specific technologies.