Plz follow the link, when you want to find the dbc file, if you are having access credentials with you.

http://robertjungerius.blogspot.com/2010/08/get-contents-of-dbc-file-without-access.html#!/2010/08/get-contents-of-dbc-file-without-access.html

or

How to find the dbc file? when we are not finding the dbc file in server manually, then follow the below approach
“/OA_HTML/jsp/fnd/aoljtest.jsp” add this path to the url of the front-end application
for ex:

My url is: http://mdsuaor1l.appshop.com:8001/ now add the above path to this url
so finally: http://mdsuaor1l.appshop.com:8001/OA_HTML/jsp/fnd/al1jtest.jsp