how to upload files to server???/

[aditi]

i have an application dat takes in user data and puts it onto data server into a database while at the same tym this is been sent to a recipient. now how can i add a utility to add attchements to it as in if the sender wants to send a file to the recipient he should be able to do it.... by uploading that file to the web server.

how can i do dat???
i am using weblogic server...