Method overloading using derived types as parameters in Java

Question

Let\'s say I have existing code which I want to extend but also to avoid changing it as much as possible.

Somewhere around this code there is a method that receives

Answer 1

That happens because Java uses single dispatch. This ends meaning that in your case, the method called depends on the type of reference "b", which is Base, and not on the type of the instance that "b" holds. Therefore, method xpto.(Base b) will always be called.

You really have to cast it or use the last approach you wrote.