What if two interface methods clash in implementation?
If two interfaces have the same method signature, they effectively declare the same method, regardless of any other intentions. Any concrete class that implements both interfaces can only provide one implementation of a given method signature, so there is no ambiguity about how the Java compiler deals with this case, only a potentially difficult design decision. If two interface methods have a clash over their method signatures and intended behaviour, it would preferable to rename one of the interface methods to indicate a more distinct purpose. Actions: Follow-up, clarify or correct this answer. Submit a new question.
