Anyway, this post's catalyst occurred this morning during my first day of a Java course I'm attending (an attempt at keeping my teeth sharp). As is custom, use of an IDE is not supported and instead attendants are to use a "normal text editor" (we all know Vim is far from "normal text editor" but bare with me here :P).
It suddenly struck me: it was time to fiddle around with code completion in Vim.
Quickly dug around and found that Vim already had code completion for some common languages (from version 7 onwards)! Java was unfortunately not on the list so I had to look for a third party solution. So far I have come across eclim, VJDE and java complete. I didn't like eclim's design (running a server with which vim would interface), and I couldn't make VJDE work for some reason, but java complete has so far been working wonders:
Just one more reason to love Vim! :D