J2EE and CI

[eluser]akkumaru[/eluser]
i've implemented MVC with J2EE before,,
with no framewrok, a standard J2EE application with servlet, JSP, and JavaBeans,,

when i start with CI, some things make me confused,,
have anyone ever compared J2EE and CI,,? please explain it to me,,


related question:
how do i make a JavaClass-like class in CI,,??
i do not mean a controller,
i mean a class which contains the application algorithm,, does the 'dirty works',, contains data and function,,

i've tried this using the 'library', but i've got problems when i put the file inside a folder,,
and i used the 'model' as interface to the database, so i avoid writing complex code in it,,

thank you for responses