Book Image

Java 9: Building Robust Modular Applications

By : Dr. Edward Lavieri, Peter Verhas, Jason Lee
Book Image

Java 9: Building Robust Modular Applications

By: Dr. Edward Lavieri, Peter Verhas, Jason Lee

Overview of this book

Java 9 and its new features add to the richness of the language; Java is one of the languages most used by developers to build robust software applications. Java 9 comes with a special emphasis on modularity with its integration with Jigsaw. This course is your one-stop guide to mastering the language. You'll be provided with an overview and explanation of the new features introduced in Java 9 and the importance of the new APIs and enhancements. Some new features of Java 9 are ground-breaking; if you are an experienced programmer, you will be able to make your enterprise applications leaner by learning these new features. You'll be provided with practical guidance in applying your newly acquired knowledge of Java 9 and further information on future developments of the Java platform. This course will improve your productivity, making your applications faster. Next, you'll go on to implement everything you've learned by building 10 cool projects. You will learn to build an email filter that separates spam messages from all your inboxes, a social media aggregator app that will help you efficiently track various feeds, and a microservice for a client/server note application, to name just a few. By the end of this course, you will be well acquainted with Java 9 features and able to build your own applications and projects. This Learning Path contains the best content from the following two recently published Packt products: • Mastering Java 9 • Java 9 Programming Blueprints
Table of Contents (33 chapters)
Title Page - Courses
Packt Upsell - Courses
Taking Notes with Monumentum

Tiered attribution for javac [JEP 215]

JEP 215 represents an impressive undertaking to streamline javac's type checking schema. Let's first review how type checking works in Java 8; then we will explore the changes in Java 9.

In Java 8, type checking of poly expressions is handled by a speculative attribution tool.


Speculative attribution is a method of type checking as part of javac's compilation process. It has a significant processing overhead.

Using the speculative attribution approach to type checking is accurate, but lacks efficiency. These checks include argument position, and are exponentially slower when testing in the midst of recursion, polymorphism, nested loops, and lambda expressions. So the goal with JEP 215 was to change the type checking schema to create faster results. The results themselves were not inaccurate with speculative attribution; they were just not generated rapidly.

The new approach, released with Java 9, uses a tiered attribution tool. This tool implements...