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

Understanding adapters

In hexagonal architecture, adapters have a different role than the adapters described in Design Patterns: Elements of Reusable Object-Oriented Software by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides. In the Gang of Four (GoF) design patterns, we use adapters to make the interfaces of two diverging classes compatible with each other. In the hexagonal architecture, we use adapters to allow a system to be compatible with different technologies or protocols. Although the adapter's role in those two approaches may differ, it would be correct to state that both approaches share the same purpose, that is, to adapt something to fit correctly into another thing.

A practical analogy to understand the role adapters play in hexagonal architecture is about remote connections to a computer. Every modern operating system is compatible with remote connection protocols. In the past and even today, in certain situations, it was common to use Telnet to...