You're reading from Designing Hexagonal Architecture with Java An architect's guide to building maintainable and change-tolerant applications with Java and Quarkus

Product type Paperback

Published in Jan 2022

Publisher Packt

ISBN-13 9781801816489

Length 460 pages

Edition 1st Edition

Languages

Java

Tools

Quarkus

Concepts

Software Architecture

Author (1):

Davi Vieira

View More author details

Table of Contents (21) Chapters

Preface

1. Section 1: Architecture Fundamentals

2. Chapter 1: Why Hexagonal Architecture? FREE CHAPTER

3. Chapter 2: Wrapping Business Rules inside Domain Hexagon

4. Chapter 3: Handling Behavior with Ports and Use Cases

5. Chapter 4: Creating Adapters to Interact with the Outside World

6. Chapter 5: Exploring the Nature of Driving and Driven Operations

7. Section 2: Using Hexagons to Create a Solid Foundation

8. Chapter 6: Building the Domain Hexagon

9. Chapter 7: Building the Application Hexagon

10. Chapter 8: Building the Framework Hexagon

11. Chapter 9: Applying Dependency Inversion with Java Modules

12. Section 3: Becoming Cloud-Native

13. Chapter 10: Adding Quarkus to a Modularized Hexagonal Application

14. Chapter 11: Leveraging CDI Beans to Manage Ports and Use Cases

15. Chapter 12: Using RESTEasy Reactive to Implement Input Adapters

16. Chapter 13: Persisting Data with Output Adapters and Hibernate Reactive

17. Chapter 14: Setting Up Dockerfile and Kubernetes Objects for Cloud Deployment

18. Chapter 15: Good Design Practices for Your Hexagonal Application

19. Assessments

20. Other Books You May Enjoy

The need to create ports and use cases

After putting some effort into modeling the problem domain in the Domain hexagon, the next step is to move on to the Application hexagon and define how the software system enables the behavior that fulfills the business-related operations that come from the Domain hexagon. Actors—who could be both users and other systems—drive these behaviors. They dictate the system's capabilities.

The moment when we start implementing the Application hexagon is crucial because we begin to think in aspects that are not directly related to the domain model. Instead, these aspects may be related to integrations for communicating with other systems. But we shouldn't go so far as to decide which technologies to use. We don't take decisions related to technology when implementing the Application hexagon. Rather, technology concerns are a subject that we go deep into in the Framework hexagon.

We employ use cases to define what a system...