Java 25 – New Features Every Developer Should Know (with Code Examples)

Java 25, released on September 16, 2025, is a Long-Term Support (LTS) release. This means enterprises will adopt it widely and it will receive updates for years to come. Beyond stability, Java 25 brings exciting features that improve performance, developer productivity, and code readability.

🔹 1. Structured Concurrency (Preview)

Structured Concurrency helps manage multiple tasks together, ensuring proper cancellation and error handling. This makes concurrent programming in Java safer and cleaner.

try (var scope = new StructuredTaskScope.ShutdownOnFailure()) {

    Future<String> user = scope.fork(() -> fetchUser());

    Future<String> orders = scope.fork(() -> fetchOrders());

    scope.join();

    scope.throwIfFailed();

    System.out.println(user.result() + " - " + orders.result());

}

Meaning: You can now group tasks and manage them as one unit — no more orphan threads.

🔹 2. Pattern Matching with Primitives

Java 25 extends pattern matching to primitives, simplifying type checks and switch statements.

static String checkNumber(Object obj) {

    return switch (obj) {

        case Integer i -> "Integer: " + i;

        case Long l    -> "Long: " + l;

        case Double d  -> "Double: " + d;

        default        -> "Unknown type";

    };

}

System.out.println(checkNumber(42));   // Integer: 42

System.out.println(checkNumber(3.14)); // Double: 3.14

Meaning: No casting required, cleaner and type-safe code.

🔹 3. Compact Object Headers

This JVM-level improvement reduces memory overhead by shrinking object headers on 64-bit platforms.

Meaning: Applications with large object graphs (AI, big data, caching) now use less memory with better garbage collection performance. No code change needed!

🔹 4. Flexible Constructor Bodies

In Java 25, you can place logic before the super() call in constructors. This allows validation or preprocessing before delegating to the parent constructor.

class Employee {

    Employee(String name) {

        System.out.println("Employee: " + name);

    }

}

class Manager extends Employee {

    Manager(String name, int level) {

        if (level < 1) throw new IllegalArgumentException("Invalid level");

        super(name); // ✅ Allowed after validation

    }

}

Meaning: Finally, you can validate constructor arguments naturally before calling the parent constructor.

🔹 5. Generational Shenandoah GC

Shenandoah GC is now generational, meaning it distinguishes between short-lived and long-lived objects for optimized collection.

java -XX:+UseShenandoahGC -XX:+UseGenerationalShenandoah

Meaning: Expect smoother performance, reduced pause times, and better scalability under load.

🔹 6. Other Notable Features

• Scoped Values – More efficient alternative to ThreadLocal for sharing immutable data across threads.
• Vector API (Incubator) – High-performance SIMD operations for AI, ML, and scientific computing.
• Key Derivation Function API – Standardized support for secure password hashing (PBKDF2, scrypt, etc.).
• PEM Encodings – Easier handling of cryptographic keys and certificates.

✅ Final Thoughts

Java 25 is not just another release — it’s a milestone. With features like structured concurrency, pattern matching for primitives, and generational GC, this LTS version sets the foundation for enterprise-ready, modern Java development.11I