We will focus on the relationship between polymorphism and Java inheritance ... several different methods, we can declare just one method that receives the generic List type.

Generics can be invariant, covariant, or contravariant, affecting how different types relate under inheritance. import java.util.List; import java.util.ArrayList; public class InvarianceExample ...

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 ...