The Java Module System

Summary Java's much-awaited "Project Jigsaw" is finally here! Java 11 includes a built-in modularity framework, and The Java Module System is your guide to discovering it. In this new book, you'll learn how the module system improves reliability and maintainability, and how it can be used to reduce tight coupling of system components. Foreword by Kevlin Henney. Purchase of the print book includes a free eBook in PDF, Kindle, and ePub formats from Manning Publications. You'll find registration instructions inside the print book. About the Technology Packaging code into neat, well-defined units makes it easier to deliver safe and reliable applications. The Java Platform Module System is a language standard for creating these units. With modules, you can closely control how JARs interact and easily identify any missing dependencies at startup. This shift in design is so fundamental that starting with Java 9, all core Java APIs are distributed as modules, and libraries, frameworks, and applications will benefit from doing the same. About the Book The Java Module System is your in-depth guide to creating and using Java modules. With detailed examples and easy-to-understand diagrams, you'll learn the anatomy of a modular Java application. Along the way, you'll master best practices for designing with modules, debugging your modular app, and deploying to production. What's inside The anatomy of a modular Java app Building modules from source to JAR Migrating to modular Java Decoupling dependencies and refining APIs Handling reflection and versioning Customizing runtime images Updated for Java 11 About the Reader Perfect for developers with some Java experience. About the Author Nicolai Parlog is a developer, author, speaker, and trainer. His home is codefx.org. Table of Contents PART 1 - Hello, modules First piece of the puzzle Anatomy of a modular application Defining modules and their properties Building modules from source to JAR Running and debugging modular applications PART 2 - Adapting real-world projects Compatibility challenges when moving to Java 9 or later Recurring challenges when running on Java 9 or later Incremental modularization of existing projects Migration and modularization strategies PART 3 - Advanced module system features Using services to decouple modules Refining dependencies and APIs Reflection in a modular world Module versions: What's possible and what's not Customizing runtime images with jlink Putting the pieces together

The upcoming Java 9 module system will affect existing applications and offer new ways of creating modular and maintainable applications. With this hands-on book, Java developers will learn not only about the joys of modularity, but also about the patterns needed to create truly modular and reliable applications. Authors Sander Mak and Paul Bakker teach you the concepts behind the Java 9 module system, along with the new tools it offers. You’ll also learn how to modularize existing code and how to build new Java applications in a modular way. Understand Java 9 module system concepts Master the patterns and practices for building truly modular applications Migrate existing applications and libraries to Java 9 modules Use JDK 9 tools for modular development and migration

Kick-start your modular programming journey and gear up for the future of Java development About This Book Master design patterns and best practices to build truly modular applications in Java 9 Upgrade your old Java code to Java 9 with ease Build and run a smooth functioning multi-module application. Who This Book Is For This book is written for Java developers who are interested in learning and understanding the techniques and best practices to build modular applications in Java. The book assumes some previous programming experience in Java 8 or earlier, familiarity with the basic Java types such as classes and interfaces, as well as experience in compiling and executing Java programs. What You Will Learn Get introduced to the concept of modules and modular programming by working on a fully modular Java application Build and configure your own Java 9 modules Work with multiple modules and establish inter-module dependencies Understand and use the principles of encapsulation, readability, and accessibility Use jlink to generate fully loaded custom runtime images like a pro Discover the best practices to help you write awesome modules that are a joy to use and maintain Upgrade your old Java code to use the new Java 9 module system In Detail 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. Style and Approach The book is a step-by-step guide to understanding Modularity and building a complete application using a modular design.

Summary Manning's bestselling Java 8 book has been revised for Java 9! In Modern Java in Action, you'll build on your existing Java language skills with the newest features and techniques. Purchase of the print book includes a free eBook in PDF, Kindle, and ePub formats from Manning Publications. About the Technology Modern applications take advantage of innovative designs, including microservices, reactive architectures, and streaming data. Modern Java features like lambdas, streams, and the long-awaited Java Module System make implementing these designs significantly easier. It's time to upgrade your skills and meet these challenges head on! About the Book Modern Java in Action connects new features of the Java language with their practical applications. Using crystal-clear examples and careful attention to detail, this book respects your time. It will help you expand your existing knowledge of core Java as you master modern additions like the Streams API and the Java Module System, explore new approaches to concurrency, and learn how functional concepts can help you write code that's easier to read and maintain. What's inside Thoroughly revised edition of Manning's bestselling Java 8 in Action New features in Java 8, Java 9, and beyond Streaming data and reactive programming The Java Module System About the Reader Written for developers familiar with core Java features. About the Author Raoul-Gabriel Urma is CEO of Cambridge Spark. Mario Fusco is a senior software engineer at Red Hat. Alan Mycroft is a University of Cambridge computer science professor; he cofounded the Raspberry Pi Foundation. Table of Contents PART 1 - FUNDAMENTALS Java 8, 9, 10, and 11: what's happening? Passing code with behavior parameterization Lambda expressions PART 2 - FUNCTIONAL-STYLE DATA PROCESSING WITH STREAMS Introducing streams Working with streams Collecting data with streams Parallel data processing and performance PART 3 - EFFECTIVE PROGRAMMING WITH STREAMS AND LAMBDAS Collection API enhancements Refactoring, testing, and debugging Domain-specific languages using lambdas PART 4 - EVERYDAY JAVA Using Optional as a better alternative to null New Date and Time API Default methods The Java Module System PART 5 - ENHANCED JAVA CONCURRENCY Concepts behind CompletableFuture and reactive programming CompletableFuture: composable asynchronous programming Reactive programming PART 6 - FUNCTIONAL PROGRAMMING AND FUTURE JAVA EVOLUTION Thinking functionally Functional programming techniques Blending OOP and FP: Comparing Java and Scala Conclusions and where next for Java

The upcoming Java 9 module system will affect existing applications and offer new ways of creating modular and maintainable applications. With this hands-on book, Java developers will learn not only about the joys of modularity, but also about the patterns needed to create truly modular and reliable applications. Authors Sander Mak and Paul Bakker teach you the concepts behind the Java 9 module system, along with the new tools it offers. You’ll also learn how to modularize existing code and how to build new Java applications in a modular way. Understand Java 9 module system concepts Master the patterns and practices for building truly modular applications Migrate existing applications and libraries to Java 9 modules Use JDK 9 tools for modular development and migration

Understanding Java from the JVM up gives you a solid foundation to grow your expertise and take on advanced techniques for performance, concurrency, containerization, and more. In The Well-Grounded Java Developer, Second Edition you will learn: The new Java module system and why you should use it Bytecode for the JVM, including operations and classloading Performance tuning the JVM Working with Java’s built-in concurrency and expanded options Programming in Kotlin and Clojure on the JVM Maximizing the benefits from your build/CI tooling with Maven and Gradle Running the JVM in containers Planning for future JVM releases The Well-Grounded Java Developer, Second Edition introduces both the modern innovations and timeless fundamentals you need to know to become a Java master. Authors Ben Evans, Martijn Verburg, and Jason Clark distill their decades of experience as Java Champions, veteran developers, and key contributors to the Java ecosystem into this clear and practical guide. You’ll discover how Java works under the hood and learn design secrets from Java’s long history. Each concept is illustrated with hands-on examples, including a fully modularized application/library and creating your own multithreaded application. Foreword by Heinz Kabutz. About the technology Java is the beating heart of enterprise software engineering. Developers who really know Java can expect easy job hunting and interesting work. Written by experts with years of boots-on-the-ground experience, this book upgrades your Java skills. It dives into powerful features like modules and concurrency models and even reveals some of Java’s deep secrets. About the book With The Well-Grounded Java Developer, Second Edition you will go beyond feature descriptions and learn how Java operates at the bytecode level. Master high-value techniques for concurrency and performance optimization, along with must-know practices for build, test, and deployment. You’ll even look at alternate JVM languages like Kotlin and Clojure. Digest this book and stand out from the pack. What's inside The new Java module system Performance tuning the JVM Maximizing CI/CD with Maven and Gradle Running the JVM in containers Planning for future JVM releases About the reader For intermediate Java developers. About the author Benjamin J. Evans is a senior principal engineer at Red Hat. Martijn Verburg is the principal SWE manager for Microsoft’s Java Engineering Group. Both Benjamin and Martijn are Java Champions. Jason Clark is a principal engineer and architect at New Relic. Table of Contents PART 1 - FROM 8 TO 11 AND BEYOND! 1 Introducing modern Java 2 Java modules 3 Java 17 PART 2 - UNDER THE HOOD 4 Class files and bytecode 5 Java concurrency fundamentals 6 JDK concurrency libraries 7 Understanding Java performance PART 3 - NON-JAVA LANGUAGES ON THE JVM 8 Alternative JVM languages 9 Kotlin 10 Clojure: A different view of programming PART 4 - BUILD AND DEPLOYMENT 11 Building with Gradle and Maven 12 Running Java in containers 13 Testing fundamentals 14 Testing beyond JUnit PART 5 - JAVA FRONTIERS 15 Advanced functional programming 16 Advanced concurrent programming 17 Modern internals 18 Future Java

Explores how to incorporate modular design thinking into Java application development.