No, not through reflection.
Reflection asks about classes and their members, you can change fields but you cannot create new ones. You cannot add new methods.
You can use a a bytecode manipulation library to add methods to classes; but why would you want to?
You can't call the methods anyway except via reflection as they would obviously not exist at compile time.
Maybe take a look at project Lombok - this is a annotation preprocessor that can add methods to classes at compile time. It will add getters and setters automagically as long as your classes are correctly annotated.
