Book Image

Get Your Hands Dirty on Clean Architecture - Second Edition

By : Tom Hombergs
4 (1)
Book Image

Get Your Hands Dirty on Clean Architecture - Second Edition

4 (1)
By: Tom Hombergs

Overview of this book

Building for maintainability is key to keep development costs low (and developers happy). The second edition of "Get Your Hands Dirty on Clean Architecture" is here to equip you with the essential skills and knowledge to build maintainable software. Building upon the success of the first edition, this comprehensive guide explores the drawbacks of conventional layered architecture and highlights the advantages of domain-centric styles such as Robert C. Martin's Clean Architecture and Alistair Cockburn's Hexagonal Architecture. Then, the book dives into hands-on chapters that show you how to manifest a Hexagonal Architecture in actual code. You'll learn in detail about different mapping strategies between the layers of a Hexagonal Architecture and see how to assemble the architecture elements into an application. The later chapters demonstrate how to enforce architecture boundaries, what shortcuts produce what types of technical debt, and how, sometimes, it is a good idea to willingly take on those debts. By the end of this second edition, you'll be armed with a deep understanding of the Hexagonal Architecture style and be ready to create maintainable web applications that save money and time. Whether you're a seasoned developer or a newcomer to the field, "Get Your Hands Dirty on Clean Architecture" will empower you to take your software architecture skills to new heights and build applications that stand the test of time.
Table of Contents (18 chapters)

Assembling via plain code

There are several ways to implement a configuration component responsible for assembling the application. If we’re building an application without the support of a dependency injection framework, we can create such a component with plain code:

This code snippet is a simplified example of how such a configuration component might look. In Java, an application is started from the main method. Within this method, we instantiate all the classes we need, from the web controller to the persistence adapter, and wire them together.

Finally, we call the mystic method startProcessingWebRequests(), which exposes the web controller via HTTP.1 The application is then ready to process requests.

1 The method startProcessingWebRequests()is just a placeholder for any bootstrapping logic that is necessary to expose our web adapters via HTTP. We don’t really want to implement this ourselves. In a real-world application, a framework...