Book Image

Get Your Hands Dirty on Clean Architecture

By : Tom Hombergs
Book Image

Get Your Hands Dirty on Clean Architecture

By: Tom Hombergs

Overview of this book

Building for maintainability is key to keeping development costs low and processes easy. 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. With this comprehensive guide, you’ll explore the drawbacks of conventional layered architecture and the advantages of domain-centric styles such as Robert C. Martin's Clean Architecture and Alistair Cockburn's Hexagonal Architecture. Then, you’ll dive into hands-on explanations on how to convert hexagonal architecture into actual code. You'll learn in detail about different mapping strategies between the layers of hexagonal architecture and discover how to assemble the architectural elements into an application. Additionally, you’ll understand how to enforce architecture boundaries, which 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.
Table of Contents (13 chapters)

Build Artifacts

Until now, our only tool for demarcating architecture boundaries within our codebase has been packaged. All of our code has been part of the same monolithic build artifact.

A build artifact is the result of a (hopefully automated) build process. Currently, the most popular build tools in the Java world are Maven and Gradle. So, until now, imagine we had a single Maven or Gradle build script and we could call Maven or Gradle to compile, test, and package the code of our application into a single JAR file.

One main feature of build tools is dependency resolution. To transform a certain codebase into a build artifact, a build tool first checks whether all the artifacts that the code base depends on are available. If not, it tries to load them from an artifact repository. If this fails, the build will fail with an error, before even trying to compile the code.

We can leverage this to enforce the dependencies (and thus, enforce the boundaries) between the modules and layers of our...