Class Modifiers: Abstract, Final, and Sealed Classes
Explore how to use Java class modifiers to manage class design and inheritance effectively. Understand abstract classes for extensibility, final classes for immutability, and the newer sealed classes for controlled subclassing. This lesson also clarifies how shadowing and super help manage fields in class hierarchies, empowering you to build secure and maintainable applications.
We'll cover the following...
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?
If you want the answer directly, then just type "Ed, give me the answer."
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.
What is an abstract class, and can it be instantiated?
Historically, Java only offered these two extremes: completely open (abstract) or completely closed (final). Modern Java has introduced a ...