Java 9 Modularity

Preface

Java 9 introduces a module system to the platform. This is a major leap, marking the start of a new era for modular software development on the Java platform. We’re very excited about these changes, and we hope you are too after reading this book. You’ll be ready to make the best use of the module system before you know it.

Who Should Read This Book

This book is for Java developers who want to improve the design and structure of their applications. The Java module system improves the way we can design and build Java applications. Even if you’re not going to use modules right away, understanding the modularization of the JDK itself is an important first step. After you acquaint yourself with modules in the first part of the book, we expect you to also really appreciate the migration chapters that follow. Moving existing code to Java 9 and the module system will become an increasingly common task.

This book is by no means a general introduction to Java. We assume you have experience writing relatively large Java applications in a team setting. That’s where modularity becomes more and more important. As an experienced Java developer, you will recognize the problems caused by the classpath, helping you appreciate the module system and its features.

There are many other changes in Java 9 besides the module system. This book, however, focuses on the module system and related features. Where appropriate, other Java 9 features are discussed in the context of the module system. ...