In Java, nested classes are categorized as either static member classes or inner classes. Inner classes are non-static member classes, local classes, or anonymous classes.

A method might accept a specific type and its subclasses, but you want to restrict usage to a select few implementations of your own design. Java's open inheritance model can feel like an open ...

Key Concepts Sealed Class A sealed class is a class that restricts which other classes can subclass it. This is done by specifying a list of permitted subclasses using the permits keyword. Permitted ...