Java 17 is a long-term support (LTS) release, meaning it will receive updates and support for an extended period. It introduced several enhancements aimed at improving performance, security, and productivity. Here are the key features:

Java 17 Features (Released September 2021)

1. Sealed Classes (Final)

  • Restricts which classes can inherit from a superclass.
  • Helps enforce better design patterns.
   
   public sealed class Animal permits Dog, Cat {}

2. Pattern Matching for switch (Preview)

  • Allows pattern matching within switch expressions.
  • Makes code more concise and readable.
   
      switch (obj) {
       case Integer i -> System.out.println("Integer: " + i);
       case String s -> System.out.println("String: " + s);
       default -> System.out.println("Unknown type");
      }

3. New macOS Rendering Pipeline

  • Uses Metal API instead of the outdated OpenGL.
  • Improves graphical performance for macOS applications.

4. Removal of Deprecated Features

  • Eliminated Applet API, which was outdated.
  • Removed Security Manager, simplifying security handling.

5. Foreign Function & Memory API (Incubating)

  • Helps Java interact with native libraries without JNI.
  • Improves interoperability with external code.

6. New RandomGenerator API

  • Provides improved and flexible random number generation.
   RandomGenerator rng = RandomGenerator.of("L128X256MixRandom");
   System.out.println(rng.nextInt(100));

Java 17 solidifies many preview features from previous versions and sets the stage for modern Java development. It’s particularly valuable for enterprise applications due to its LTS status.