Migrating to Java 9 Modules

Explore the challenges and strategies for migrating existing Java applications to the new module system introduced in Java 9. Learn about automatic modules, unnamed modules, and command-line arguments designed to ease the transition. Dive into practical examples based on a Spring/Hibernate application, addressing common migration issues and gaining insights into the module framework. Discover valuable tips for preparing your codebase for modularization, including handling third-party libraries, resolving missing platform modules, and dealing with deep reflection. Understand the mental model of your application's structure and how Java 9 modules can improve it. Follow a step-by-step migration process, covering topics such as classpath migration, using jdeps for problem detection, leveraging automatic modules, and working with open modules and packages.

Intro
Migrating to Java 9
Today's journey
Classpath migration problems
Missing platform modules
Modular JDK
Add unresolved platform modules
Deep reflection
Using encapsulated APIs
Use jdeps to find problems
Mental picture of your app
Actual view of your app
Java 9 modules make this possible!
Classic classpath
Top down migration
Using Automatic Modules
Open Modules
Open Packages
Migration steps - recap