Ports act as the gates to the Core. They are standard Java interfaces.
The adapters implement the specific technologies and frameworks used by the application. For example, we can create a database adapter that implements the UserRepository interface:
to orchestrate software-specific behaviors without detailing how data is retrieved or sent. Framework Hexagon
Alistair Cockburn introduced Hexagonal Architecture to solve these coupling issues. The architecture places the core business logic inside an isolated domain hexagon. Ports act as the gates to the Core
The center of the hexagon contains the business models, entities, and pure business logic. This code must be written in pure Java. It should have absolutely zero dependencies on external frameworks like Spring Boot, Hibernate, or Quarkus.
The center of the hexagon contains your business models, rules, and use cases. This code is pure Java. It has zero dependencies on frameworks like Spring, Hibernate, or AWS SDKs. The Outside (Infrastructure)
To get started today:
Keep @Component , @Service , and @Entity tags completely out of your domain package. Configure beans using a standalone @Configuration class in your infrastructure layer instead.
Hexagonal architecture, or the pattern, decouples core business logic from external technologies like databases or UIs. The 2021 book Designing Hexagonal Architecture with Java by Davi Vieira provides a modern guide for implementing this in Java using frameworks like Quarkus . 📖 Accessing the Book
An connects the outbound port to an actual database: For example, we can create a database adapter
Hexagonal Architecture is an architectural pattern that was first introduced by Alistair Cockburn in 2005. The pattern is called "hexagonal" because it visualizes the architecture as a hexagon with the core business logic at its center. The hexagon is surrounded by ports and adapters that interact with the outside world.
This comprehensive guide breaks down the principles of Hexagonal Architecture (Ports and Adapters) in Java, providing practical code examples and structural insights that mirror high-quality engineering literature. 1. What is Hexagonal Architecture?
Developers focusing on business features can build out entire workflows inside the core without worrying about JSON serialization, HTTP headers, or SQL schemas. 6. Best Practices and Potential Pitfalls The center of the hexagon contains the business
In a standard three-tier architecture (Presentation -> Business -> Data Access), the business layer directly depends on the data access layer.
A clean package structure enforces architectural boundaries. Java modules or standard packages can organize a project by separating the domain from infrastructure.