Book Image

Domain-Driven Design with Java - A Practitioner’s Guide

By : Premanand Chandrasekaran, Karthik Krishnan
Book Image

Domain-Driven Design with Java - A Practitioner’s Guide

By: Premanand Chandrasekaran, Karthik Krishnan

Overview of this book

Domain-Driven Design (DDD) makes available a set of techniques and patterns that enable domain experts, architects, and developers to work together to decompose complex business problems into a set of well-factored, collaborating, and loosely coupled subsystems. This practical guide will help you as a developer and architect to put your knowledge to work in order to create elegant software designs that are enjoyable to work with and easy to reason about. You'll begin with an introduction to the concepts of domain-driven design and discover various ways to apply them in real-world scenarios. You'll also appreciate how DDD is extremely relevant when creating cloud native solutions that employ modern techniques such as event-driven microservices and fine-grained architectures. As you advance through the chapters, you'll get acquainted with core DDD’s strategic design concepts such as the ubiquitous language, context maps, bounded contexts, and tactical design elements like aggregates and domain models and events. You'll understand how to apply modern, lightweight modeling techniques such as business value canvas, Wardley mapping, domain storytelling, and event storming, while also learning how to test-drive the system to create solutions that exhibit high degrees of internal quality. By the end of this software design book, you'll be able to architect, design, and implement robust, resilient, and performant distributed software solutions.
Table of Contents (17 chapters)
Part 1: Foundations
Part 2: Real-World DDD
Part 3: Evolution Patterns

Programming paradigms

The tactical elements of DDD introduce a specific vocabulary (aggregates, entities, value objects, repositories, services, factories, domain events, and so on) when arriving at a solution. At the end of the day, we need to translate these concepts into running software. Over the years, we have employed a variety of programming paradigms, including procedural, object-oriented, functional, and aspect-oriented. Is it possible to apply DDD in conjunction with one or more of these paradigms? In this section, we will explore how some common programming paradigms and techniques help us express tactical design elements in code.

Object-oriented programming

On the surface of it, DDD seems to simply replicate a set of OO terms and call them by different names. For example, the central concepts of tactical DDD such as aggregates, entities, and value objects could simply be referred to as objects in OO terms. Others such as services may not have a direct OO analog. So...