Book Image

Java 11 and 12 ??? New Features

By : Mala Gupta
Book Image

Java 11 and 12 ??? New Features

By: Mala Gupta

Overview of this book

With its new six-monthly release cadence, Java is moving forward faster. In addition to planned version releases, a lot of work is currently being undertaken on various Java projects at Oracle. In order to make best use of the new features in their applications and libraries, you must be well-versed with the most recent advancements. Java 11 and 12 – New Features will take you through the latest developments in Java, right from variable type inference and simplified multithreading through to performance improvements, which are covered in depth to help you make your applications more efficient. This book explains the relevance and applicability of Java's new features, and answers your questions on whether to invest in migrating to new Java versions and when to migrate. You'll also get to grips with platform features, such as AppCDS and new garbage collectors, to tune and optimize your application—from reduced launch time and latency to improved performance and throughput. By the end of this book, you will be equipped with a thorough understanding of the new features of Java 11, 12, and Project Amber, and possess the skills to apply them with a view to improving your application's performance.
Table of Contents (23 chapters)
Free Chapter
1
Section 1: JDK 10
6
Section 2: JDK 11
13
Section 3: JDK 12
16
Section 4: Project Amber

Type inference with var

The following lines of code show how local variables (and all other variables) were defined prior to Java 10:

String name = "Java Everywhere"; 
LocalDateTime dateTime = new LocalDateTime.now();

Starting with Java 10, by using var, you can drop the mandatory explicit type in the declaration of local variables, as follows:

var name = "Java Everywhere";            // variable 'name' inferred as 
// String var dateTime = new LocalDateTime.now(); // var 'dateTime' inferred as
// LocalDateTime

Does it look like the preceding code doesn't offer a lot of benefits? Imagine you could take the following code:

HashMap<Integer, String> map = new HashMap<Integer, String>(); 

And replace it with this code, instead:

var map =...