You might need to be a bit clearer with your question... Two possible interpretations I can think of are:
(1) Changing or reading the environment variables (ie. PATH, TERM, etc.) from Java - information can be found here
. I'm not sure why it would matter
, but it would certainly change
based on login ID, because different users will have different .bashrc / .zshrc files, so will have different environment variables.
(2) Setting up the environment variables to allow you to use java to compile things - linked here
Obviously, if I have misunderstood your question, please do correct me
Hope this helps,