Java Core Language Standards

Modern Java Features (17+)

// Records - immutable data carriers
public record User(String id, String name, String email) {
    // Compact constructor for validation
    public User {
        Objects.requireNonNull(id);
        Objects.requireNonNull(name);
    }
}

// Sealed classes - restricted inheritance
public sealed interface Shape permits Circle, Rectangle, Triangle {}
public record Circle(double radius) implements Shape {}
public record Rectangle(double width, double height) implements Shape {}
public final class Triangle implements Shape { /* ... */ }