Question

Since interfaces contains only empty methods (in java) ,then why do we implement these interfaces ?what's the use of implementing these empty methods ?
is Overriding a factor here ?

Answer 1

There are a number of reasons to implement interfaces. One of the chief reasons is Java allows only one tree of inheritance, thus a class can only inherit fron a single ancestor class line. Interfaces, to some extent, overcome the limitation of single tree inheritance by allowing a class to implement methods from multiple ancestors. The discussion can get much more technical but this is a simplified single reason for interfaces.