What new features of Java 17/21 do you use?

Java 17 and 21 introduced several interesting features that I use in my projects:

• Pattern Matching for instanceof (Java 17): simplifies type checking and casting, making the code cleaner.

• Sealed Classes (Java 17): allow restricting inheritance, which improves control over class hierarchies.

• Records (Java 17): a convenient way to create immutable classes with minimal boilerplate code.

• Foreign Function & Memory API (experimental in Java 21): simplifies interaction with native code without JNI.

• Virtual Threads (Java 21, Project Loom): significantly simplify multithreading and increase application scalability.

Example of using Records:

public record User(String name, int age) {}

User user = new User("Alice", 30);
System.out.println(user.name());

These features help write more concise, safe, and performant code.