php executable and environmental variables

Hello all, I am trying to implement a simple web server (in Java) and I want to add php support. For the moment I do a "Process p = Runtime.getRuntime().exec("php /path/to/php/file")", I grab the output, seperate headers from body and send it back to the client. For simple php pages this thing works fine. But (obviously) it does not work for pages requiring parameters. So my question is what exactly the php executable searches for in the environment? Which are the (CGI???) variables I'll have to set so that it will process POST and GET correctly? Tnx in advance, Tom. -- Klein bottle for sale... inquire within.