Class Modifiers: Abstract, Final, and Sealed Classes
Explore Java class modifiers to control how classes can be extended or restricted. Understand abstract classes for extensibility, final classes for immutability, and sealed classes for restricted inheritance, improving design security and flexibility.
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When designing a robust Java application, we must carefully dictate how our classes can be used by other developers. Should the class be a mere template that forces other developers to fill in the blanks? Should it be completely locked down to guarantee security and immutability? Or should it be something securely in between?
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Let us explore how class-level modifiers give us strict control over our class architecture.
What is an abstract class, and can it be instantiated?
While abstract classes leave the door wide open for extension, sometimes we need to permanently close that door to protect the integrity of our application.
Why are core Java classes like String marked as final, and what security risks would exist if they weren't?
Historically, Java only offered these two extremes: completely open (abstract) or completely closed (final). Modern Java has introduced a ...