raw use of parameterized class

This is the preferred way to use the instanceof operator with generic types: Note that once you’ve determined that o is a Set, you must cast it to the wildcard type Set, not the raw type Set. Does the question mark really buy you anything? If you want to use a generic type but you don’t know or care what the actual type parameter is, you can use a question mark instead. For example, the unbounded wildcard type for the generic type Set is Set (read “set of some type”). Let's take a look at how we can create our custom NamedPreparedStatement in which we can pass parameters by name and create named parameterized … Box − Box is a generic class. A generic class declaration looks like a non-generic class declaration, except that the class name is followed by a type parameter section. There are sub-typing rules for generics, and List is a subtype of the raw type List, but not of the parameterized type List