Designing Hexagonal Architecture with Java

Software architects and Java developers will be able to put their knowledge to work with this practical guide to building hexagonal applications using Java and Quarkus. With an emphasis on solving complexities from muddled code structures lacking separation of concerns, this book provides a comprehensive way to create maintainable systems.

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A practical guide for software architects and Java developers to build cloud-native hexagonal applications using Java and Quarkus to create systems that are easier to refactor, scale, and maintain

Key Features

Learn techniques to decouple business and technology code in an application
Apply hexagonal architecture principles to produce more organized, coherent, and maintainable software
Minimize technical debts and tackle complexities derived from multiple teams dealing with the same code base

Book DescriptionHexagonal architecture enhances developers' productivity by decoupling business code from technology code, making the software more change-tolerant, and allowing it to evolve and incorporate new technologies without the need for significant refactoring. By adhering to hexagonal principles, you can structure your software in a way that reduces the effort required to understand and maintain the code.

This book starts with an in-depth analysis of hexagonal architecture's building blocks, such as entities, use cases, ports, and adapters. You'll learn how to assemble business code in the Domain hexagon, create features by using ports and use cases in the Application hexagon, and make your software compatible with different technologies by employing adapters in the Framework hexagon. Moving on, you'll get your hands dirty developing a system based on a real-world scenario applying all the hexagonal architecture's building blocks. By creating a hexagonal system, you'll also understand how you can use Java modules to reinforce dependency inversion and ensure the isolation of each hexagon in the architecture. Finally, you'll get to grips with using Quarkus to turn your hexagonal application into a cloud-native system.

By the end of this hexagonal architecture book, you'll be able to bring order and sanity to the development of complex and long-lasting applications.

What you will learn

Find out how to assemble business rules algorithms using the specification design pattern
Combine domain-driven design techniques with hexagonal principles to create powerful domain models
Employ adapters to make the system support different protocols such as REST, gRPC, and WebSocket
Create a module and package structure based on hexagonal principles
Use Java modules to enforce dependency inversion and ensure isolation between software components
Implement Quarkus DI to manage the life cycle of input and output ports

Who this book is forThis book is for software architects and Java developers who want to improve code maintainability and enhance productivity with an architecture that allows changes in technology without compromising business logic, which is precisely what hexagonal architecture does. Intermediate knowledge of the Java programming language and familiarity with Jakarta EE will help you to get the most out of this book.