Java 17: What I Loved and Learned

Why Java 17?

Java 17 is an LTS (Long-Term Support) release, which means production-grade stability for years ahead. That alone was enough motivation. But the real joy was discovering how much cleaner, expressive, and powerful the language has become.

What Stood Out for Me

Pattern Matching for Switch (JEP 406)

One of my absolute favorite features. It reduces boilerplate dramatically. I used to write cumbersome if-else blocks or instanceof chains. Now, I can simply do:

return switch (obj) {
    case String s -> "It's a string: " + s;
    case Integer i -> "It's an int: " + i;
    default -> "Unknown type";
};

Sealed Classes (JEP 409)

I’ve always wanted a way to restrict which classes can extend a base class without relying on package-private constructors. Sealed classes finally make this clean and explicit:

public sealed class Shape permits Circle, Square {}

New Random Generators (JEP 356)

Switching between algorithms like LXM, Xoshiro, or Legacy Random is now easy and clean. Great for test data generation:

RandomGenerator rng = RandomGeneratorFactory.of("L64X256MixRandom").create();

Foreign Function & Memory API (JEP 412 - Incubator)

This one is big. Calling C code from Java without JNI's verbose ceremony? Yes, please. It still feels early-stage, but for some native integrations I had, this drastically simplified the process.

Vector API (JEP 414 - Incubator)

I’ve experimented with this in a math-heavy side project. The performance gain when doing SIMD operations is legit. If you work with large numerical datasets or image processing, keep an eye on this.

Encapsulation of JDK Internals (JEP 403)

Accessing internal APIs is now completely blocked. It hurt at first because some legacy libraries I used depended on them, but in the long run, it’s the right move.

The Small but Important Bits

• Applet API? Finally gone. Nostalgic, but irrelevant.
• RMI Activation? Removed.
• Security Manager? Deprecated for removal — and I agree.
• OpenGL pipeline on macOS replaced with Metal (JEP 382)? Much needed.

New Release Cadence & LTS Cycle

Java now has a 6-month release cycle and a 2-year LTS model. This is huge. It allows experimentation and faster iteration while giving enterprises a solid LTS version to rely on. Java 17 fits right into this model.

Final Thoughts

Java 17 isn’t just another version. It’s a statement that Java is very much alive, modern, and evolving. As someone who has spent years in the Java ecosystem, I’m more confident than ever to build new projects on Java 17.

If you're still on Java 8 or 11, it's time to level up. The productivity gains, cleaner syntax, and performance improvements are worth the migration.