Did you consider that your web application may be war
or ear and your web app  server doesn't allow putting
many different materials in its web! So it's nice to
take any easy but may be its better to anticipate the
effects! You and another friend are fans of direct
directory accessing (Shared directory) but Do you now
by means of this approach you allow that everyone
access your server life! If certainly these approaches
work well there is no need to developed applications
which provides FTP facilities in themselves!

So I provide my approach as a student project not as a
comprehensive or even complete and best solution so
you must consider the conditions and need of Software!
Althogh I think that in any condition I will not
suggest file  sharing or putting files  in the web
application directory for this purpose!