Java 24 Features

Clean, structured and easy-to-navigate Java reference

Category	Feature	Description	Status in Java 24
Language	Primitive Types in Patterns	Allows pattern matching with primitive types (e.g., int, double)	Preview
Language	Flexible Constructor Bodies	More flexibility in constructor execution order	Preview
Language	Module Import Declarations	Simplifies usage of modules with shorter import syntax	Preview
Language	Enhanced Pattern Matching	Further improvements to pattern matching in switch	Final / Enhanced
JVM	Compact Object Headers	Reduces object header size to improve memory efficiency	Preview
JVM	Class-File API Updates	Programmatic parsing & generation of class files	Final / Improved
Concurrency	Structured Concurrency Updates	Improvements for managing multiple threads as a unit	Enhanced
Performance	GC & Runtime Optimizations	Performance improvements in G1, ZGC	Improved
Security	Stronger Encapsulation	Continued tightening of internal API access	Enhanced
Tooling	JDK Toolchain Improvements	Better diagnostics & performance tuning support	Improved

static String check(Object obj) {

return switch (obj) {

case int i -> "Primitive int: " + i;

case double d -> "Primitive double: " + d;

default -> "Other";

};

}

Allows statements before calling super() or this() under controlled conditions.

class Person {

Person(String name) {

validate(name);

this.name = name;

}

✔ Cleaner validation logic
✔ More readable constructors

Ø Reduces memory footprint

Ø Helpful for large-scale applications

Ø Better performance in memory-heavy systems

Ø Continues modernization of pattern matching

Ø Memory efficiency improvements

Ø Cleaner modular programming

Ø Better concurrency management

Ø Runtime & GC performance enhancements

Java 17 (LTS)	Java 24
Stable enterprise baseline	Innovation-focused release
Sealed classes	Primitive patterns
Basic pattern matching	Advanced pattern matching
Standard object headers	Compact object headers
Traditional constructors	Flexible constructor bodies