Java 9 is bringing lots of new enhancements and the biggest change is the modularization of Java. It’s another big change after Lambdas in Java 8. In this tutorial, you will learn Java 9 features with examples.

New Features

There are 90+ enhancements added to Java 9, the most significant ones are mentioned below −

Module − A new kind of Java programing component introduced as a module, which is a named, self-describing collection of code and data.
REPL (JShell) − Read-Eval-Print Loop (REPL) capability added to the Java platform.
HTTP 2 Client − new HTTPClient API supporting WebSockets and HTTP 2 streams and server push features.
Improved JavaDocs − Supports HTML5 output generation. Provides a search box to generated API documentation.
Multi release JAR − Enhances the JAR format so that multiple, Java release-specific versions of class files can coexist in a single archive.
Collection Factory Methods − New static factory methods for List, Set, and Map interfaces to create immutable instances of those collections.
Private Interface Methods − Enhanced interfaces with private and private static methods.
Process API Improvements − Improved API to control and manage operating system processes.
Stream API Improvements − Enhanced security and robustness by allowing incoming streams of object-serialization data to be filtered.
Try With Resources improvement − Now final variables can be used as resources in the try-with-resources statement.
Enhanced @Deprecated Annotation − @Deprecated annotation revamped to provide more information about the status and intended disposition of an API.
Inner Class Diamond Operator − Allow the diamond operator to be used with anonymous classes if the argument type of the inferred type can be denoted.
Optional Class Improvements − New useful methods are added to java.util.Optional class.
Multiresolution Image API − Supports the encapsulation of a set of images with different resolutions into a single multiresolution image.
CompletableFuture API improvements − The asynchronous mechanisms of the CompletableFuture class can perform an action when the process exits with ProcessHandle.onExit method.
Lightweight JSON − A lightweight API introduced to consume and generating documents and data streams via JSON in java 9.
Reactive Streams API − A new Reactive Streams API in Java SE 9 has been introduced to support reactive programming in java 9.

Java 9 Examples

Java 9 Private Methods in Interface with Examples - Learn how to use private methods in interface with examples.

Java 9 List.of() Method - Create Immutable List Example - In this post, I show you how to create an immutable list using Java 9 provided List.of() static factory method.

Java 9 Set.of() Method - Create Immutable Set Example - In this post, I show you how to create an immutable Set using Java 9 provided Set.of() static factory method.

Java 9 Map.ofEntries() Method - Create Immutable Map Example - In this post, I show you how to create an immutable Map using Java 9 provided Map.ofEntries() static factory method.

Java 9 - Stream API Improvements with Examples - In this article, we will learn what are the Stream API improvements made in Java 9 with an example.