how to create a folder in tomcat webserver using java program?

i want to know how to create a folder in webserver(tomcat 7.0) in java.

iam recently start one project.In that project i need to upload files into server from the client machine.In this each client has his own folder in server and upload the files into them.

And in each user folder we have more than two jsp files.when user request the server to show their content by an url (eg:ipaddress:portnumber/userid/index.jsp) using that files i want to show his uploaded data.

is it possible.?

please,guide me to solve this problem.
thanks.

---