Method has the same erasure as another method in type

Question

Why is it not legal to have the following two methods in the same class?

class Test{
   void add(Set ii){}
   void add(Set ss){}         


        

Answer 1

This is because Java Generics are implemented with Type Erasure.

Your methods would be translated, at compile time, to something like:

Method resolution occurs at compile time and doesn't consider type parameters. (see erickson's answer)

void add(Set ii);
void add(Set ss);

Both methods have the same signature without the type parameters, hence the error.