It's nothing related to the nickname or ident. jIRC allows you to customize your ident/nickname as you wish, and yet users are still somehow recognized as being Javas regardless of the information they supply. As for the CTCP, try opening a socket to any servers on any network. I have never seen any servers that issue a CTCP version to every connecting clients. And as far as i know, Java uses pretty much the same methods as any other IRC clients.
