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

Changes to frontend interactions

Currently, the JavaFX frontend interacts with the rest of the application by making request-response style in-process method calls (that is, CommandGateway for commands and QueryGateway for queries), as shown here:

One very simple way to replace these in-process calls is to introduce some form of Remote Procedure Call (RPC). Now our application looks similar to the following:

Figure 10.2 – Introducing remote interaction with the frontend

When working with in-process interactions, we are simply invoking methods on objects within the confines of the same process. However, when we switch to using out-of-process calls, there are quite a few considerations. These days when working with remote APIs, we have several popular choices in the form of JSON-based web services, GraphQL, gRPC, and more. While it is possible to make use of a completely custom format to facilitate the communication, DDD advocates...