Overloading hassle with no args, different return types

Question

We're trying to create a document object that can be parsed from XML with xerces and then used as the model for a jtree and a styled-text editor. That means we want to:
1. subclass stuff from org.w3c.dom
2. implement interfaces from javax.swing.tree
3. implement interfaces from javax.swing.text
We figured that since they all represent similar tree structures, this would be a nice and clever thing to do.
Hit a snag this morning:
* org.w3c.dom.Node.getAttributes() returns NamedNodeMap
* javax.swing.text.Element.getAttributes() returns AttributeSet
So, our class gets a compile error on the conflicting return types for what it thinks is the same method.
Any suggestions for what to do? Abandoning xerces isn't an option, and rewriting styled text ourselves isn't practial either.
--Chris (invalidname)

Answer 1

This is the problem with multiple inheritance. In C++, the problem is more pronounced because you can inherit two implmentations of the same method.
In Java, whenever you inherit two methods with the same signature, even if the return types are the same, you have a similar problem. These two methods will likely have two different contracts, and you cannot fulfuill both contracts with one method.
Example:
interface Graphical { /** Draw object on screen */ void draw() { } }
interface CardDeck { /** Draw a card */ void draw() { } }
class CardGame implements Graphical, CardDeck { /** ??? */ void draw() { } }It is unfortunate that you're inheriting two different getAttributes() methods. You'll have to use composition and delegation instead of inheritance to get around the problem.