What are sealed classes in Java 17 and can you provide examples?

What are sealed classes in Java 17 and can you provide examples?

Sealed classes in Java 17 restrict which classes can extend them. For example, you can define a sealed class Shape and allow only specific subclasses like Circle and Square.

Can you show me a code example of how to implement sealed classes?

Sure! Here's a simple example:

public sealed class Shape permits Circle, Square {
}

public final class Circle extends Shape {
}

public final class Square extends Shape {
}

What are the benefits of using sealed classes?

Sealed classes provide better control over class hierarchies, enhance security, and improve maintainability by limiting subclassing.

Are there any limitations to using sealed classes?

Yes, sealed classes can only be extended by the classes specified in the permits clause, which may limit flexibility in some cases.