Question

For example a class has public do, packaged do, protected do, and private do. If an instance of the class calls do it gets the private one, if a subclass calls it, then it gets protected, if a same package calls it, then it gets packaged and if anything else calls it, it gets public?

Answer 1

No.

It is a compile-time error to declare
two methods with override-equivalent
signatures (defined below) in a class.
Two methods have the same signature if
they have the same name and argument
types.

(From JLS §8.4.2)