Why Use `final` Classes in Java?

The Significance of "final class" in Java

Declaring an entire class as final may initially seem counterintuitive, but it serves a specific purpose in Java. Unlike the final modifier applied to variables and methods, a final class signifies that it cannot be extended by other classes.

Applications of Final Classes

Programmers do indeed utilize this feature in their programs for several reasons. One of the primary motivations is to prevent illicit class inheritance. To prevent unwanted subclasses, particularly when the original class implementation should not be altered, a class is marked as final.

Furthermore, final classes offer security enhancements. By prohibiting subclassing, they ensure that the original class's behavior cannot be modified by subclasses with malicious intent.

Object-Oriented Principles and Final Classes

While Java is an object-oriented language, marking a class as final does not entirely negate the principles of object-oriented programming. It primarily restricts the inheritance aspect of classes.

Final classes still adhere to other object-oriented principles, such as encapsulation, abstraction, and polymorphism. They can have state and behavior defined by methods, and they can be used to create objects that interact with other objects in the program.

When to Use Final Classes

The decision of whether to declare a class as final should be made carefully. Here are some situations where it is particularly appropriate:

• When you want to ensure that the class design is complete and should not be modified.
• When the class contains highly sensitive or critical functionality that must not be overridden.
• When preventing subclassing enhances the security of your application.

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