Book Image

Modular Programming in Java 9

By : Koushik Srinivas Kothagal
Book Image

Modular Programming in Java 9

By: Koushik Srinivas Kothagal

Overview of this book

The Java 9 module system is an important addition to the language that affects the way we design, write, and organize code and libraries in Java. It provides a new way to achieve maintainable code by the encapsulation of Java types, as well as a way to write better libraries that have clear interfaces. Effectively using the module system requires an understanding of how modules work and what the best practices of creating modules are. This book will give you step-by-step instructions to create new modules as well as migrate code from earlier versions of Java to the Java 9 module system. You'll be working on a fully modular sample application and add features to it as you learn about Java modules. You'll learn how to create module definitions, setup inter-module dependencies, and use the built-in modules from the modular JDK. You will also learn about module resolution and how to use jlink to generate custom runtime images. We will end our journey by taking a look at the road ahead. You will learn some powerful best practices that will help you as you start building modular applications. You will also learn how to upgrade an existing Java 8 codebase to Java 9, handle issues with libraries, and how to test Java 9 applications.
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

Java modules coding patterns and strategies


We've so far looked at some general higher level, almost common-sensical patterns, that apply to modularity in Java. Now let's dive into code. Let's look at some code patterns and strategies that can help you as you as you start designing modules and their APIs. Each of these strategies are presented with explanation about the pattern, why and when you should consider using them. Many of them have accompanying code examples for you to refer to. Some of these might be obvious. In fact, we've even applied some of the patterns when building the sample address book application we've worked on in this book. I hope this consolidated list provides you with a good reference to these patterns when designing and building modular applications.

Pattern 1 - Public interface, private implementation, and factory class

Separate the public API from the internal encapsulated implementation (we've already seen this strategy implemented in the sorting utility module...