Developing a plugin, cant find docs on getting server stats info

Hi im developing a plugin which is a secret until i have at least most of the functionality in it then ill go into public beta, but what i need is be able to grab the number of online players, a list of player names, number of max slots.


if you need more info please ask, thanks in advance.
this is my first plugin so i am a n00b, and infact my first time dev'ing in java