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

Summary


In this chapter, we've created a second Java module and established inter-module dependency. We learned how to set up requires and exports in module definition files. With two modules, we are finally able to see the modularity features that attempt to solve some of the problems in code organization and management that we've discussed in Chapter 1,Introducing Java 9 Modularity.

Now that we have a basic understanding of how to create Java 9 modules and use them in other modules, let's focus our attention to the platform itself. Java 9 not only comes with the module system that's meant for developers to use in order to create modules, it also comes with a completely revamped JRE and JDK that are themselves modularized. In the next chapter, you'll learn about the modularization of the platform, how it affects developers, and how it is, in a way, essential for bringing in modularity support into the Java language.