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

Summary

We learned in this chapter that adapters are used to define the technologies that are supported by a hexagonal application. We created two input adapters to allow driving operations, that is, a REST adapter to receive data from HTTP connections and a CLI adapter to receive data from STDIN. Both input adapters were attached to the same input port, allowing the hexagonal system to use the same logic to process requests coming in distinct formats.

Then, we created an H2 database output adapter and a JSON file output adapter to make the hexagonal application communicate with different data sources. These two output adapters were attached to the same output port, enabling the hexagonal system to persist and obtain data from external sources so that the data source technology did not influence the business logic.

By knowing the purpose of input and output adapters and understanding how to implement them, we can now create systems that can tolerate significant technological...