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
Preface
25
Taking Notes with Monumentum
Bibliography
Index

Optimizing string concatenation [JEP 280]


JEP 280 is an interesting enhancement for the Java platform. Prior to Java 9, string concatenation was translated by javac intoStringBuilder : : appendchains. This was a sub-optimal translation methodology often requiring StringBuilder presizing.

The enhancement changed the string concatenation bytecode sequence, generated by javac, so that it uses INVOKEDYNAMIC calls. The purpose of the enhancement was to increase optimization and to support future optimizations without the need to reformat the javac's bytecode.

Note

See JEP 276 for more information on INVOKEDYNAMIC.

The use of INVOKEDYAMIC calls to java.lang.invoke.StringConcatFactory allows us to use a methodology similar to lambda expressions instead of using StringBuilder's step-wise process. This results in more efficient processing of string concatenation.