Java 17 Features

 

☕ Complete List of Features in Java 17 (LTS) ☕ | by Brijesh Srivastava | Medium

Sealed Classes  - This feature provides more control over class hierarchies by restricting which classes can extend or implement a given class or interface

public sealed class Vehicle permits Car, Truck { }

Pattern Matching for switch -  Instanceof Pattern Matching (Finalized from Java 16) 

Java 17 introduces Pattern Matching for switch as a preview feature. This enhancement simplifies the use of switch statements by allowing patterns to be used in case labels. Pattern matching makes code more readable and reduces the need for explicit type casting.

Example:

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public static String getShapeType(Object shape) {     return switch (shape) {         case Circle c -> "Circle with radius " + c.radius();         case Rectangle r -> "Rectangle with width " + r.width() + " and height " + r.height();         default -> "Unknown shape";     }; }

This feature improves code clarity and reduces boilerplate when dealing with complex object hierarchies in switch statements.

Records (Finalized from Java 16) 

Key Features and Characteristics of Java Records:

• Immutability:

  All components (fields) declared in a record are implicitly final, meaning their values cannot be changed after the record instance is created. This promotes thread-safety and predictable behavior.
• Concise Syntax:
• Records automatically generate common methods like the canonical constructor, accessor methods (named after the components), equals(), hashCode(), and toString(). 

 Text Blocks – Multi-line string literals (""")

5. JEP 356: Enhanced Pseudo-Random Number Generators (PRNGs)

Java 17 introduces enhanced pseudo-random number generators (PRNGs), providing a more robust API for generating random numbers. This new API includes support for stream-based APIs and new algorithms like LXM, which offer better statistical properties for certain applications.

Example:

1 2	RandomGenerator random = RandomGenerator.of("L64X128MixRandom"); System.out.println(random.nextInt());

These improvements enhance randomness quality, particularly for applications requiring secure random numbers or better distribution for simulations.

Performance & Memory Improvements - ZGC (Z Garbage Collector) Enhancements — Lower latency, better scalability.

New APIs in Java 17

In addition to these language and performance enhancements, Java 17 introduces several new APIs to make development easier and more powerful:

• Foreign Function & Memory API: An API for working with native memory and calling native code outside the JVM.
• Vector API: A new API for vector computation, offering better performance for certain workloads.
• Enhanced JDK Flight Recorder: Expanded support for monitoring and troubleshooting applications at runtime.