Java 9 Tutorial

📘 Premium Read: Access my best content on Medium member-only articles — deep dives into Java, Spring Boot, Microservices, backend architecture, interview preparation, career advice, and industry-standard best practices.

🎓 Top 15 Udemy Courses (80-90% Discount): My Udemy Courses - Ramesh Fadatare — All my Udemy courses are real-time and project oriented courses.

▶️ Subscribe to My YouTube Channel (176K+ subscribers): Java Guides on YouTube

▶️ For AI, ChatGPT, Web, Tech, and Generative AI, subscribe to another channel: Ramesh Fadatare on YouTube

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 generate 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 filtered incoming streams of object-serialization data.
• Try With Resources improvement − Now final variables can be used as resources in the try-with-resources statement.
• Enhanced @Deprecated Annotation − @Deprecated annotation is 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 generate 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 Tutorials and 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.

• Java 9 - Optional Class Improvements with Examples - Learn Optional class improvements with examples.

JShell Tutorials

• Java Shell - JShell Tutorial - In this tutorial, we will learn how to use JShell which is introduced in Java 9.

• Java JShell Import - In this tutorial, we will learn how to work with import statements using JShell. We will also see how to import third-party library imports using JShell.

• Java JShell Commands - In this tutorial, we will see the usage of commonly used JShell commands with an example.