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)

Responsibilities of a persistence adapter

Let’s have a look at what a persistence adapter usually does:

  1. Takes the input.
  2. Maps the input into database format.
  3. Sends the input to the database.
  4. Maps the database output into application format.
  5. Returns the output.

The persistence adapter takes input through a port interface. The input model may be a domain entity or an object dedicated to a specific database operation, as specified by the interface.

It then maps the input model to a format it can work with to modify or query the database. In Java projects, we commonly use the Java Persistence API (JPA) to talk to a database, so we might map the input into JPA entity objects that reflect the structure of the database tables. Depending on the context, mapping the input model into JPA entities may be a lot of work for little gain, so we’ll talk about strategies without mapping in Chapter 9, Mapping between Boundaries.

Instead of using JPA...