Java generics void/Void types

Question

I am implementing a ResponseHandler for the apache HttpClient package, like so:

new ResponseHandler() {
    public int handleResponse         


        

Answer 1

The Void type was created for this exact situation: to create a method with a generic return type where a subtype can be "void". Void was designed in such a way that no objects of that type can possibly be created. Thus a method of type Void will always return null (or complete abnormally), which is as close to nothing as you are going to get. You do have to put return null in the method, but this should only be a minor inconvenience.

In short: Do use Void.