I have read enough trying to understand what is Java's Interface, why we should use it and also what is the main reason to use it.
I understand, in technical, once i have "implements" one interface class, i have to put the method within that interface class into my program.
Why i should do that? I dont know. Because i that method i still can put it in if i didnt implemnts that Interface.
Cany someone share with me some practical usage of Interface in our real time system development?