Java: how to upload files to server and handle authentication?

I have a small linux vps. I have written a Java client application, which needs to connect and submit large string data and images. The string data will be stored as regular text files on the server, and will be parsed by another Java application that will run on the server and use this 开发者_运维知识库uploaded files and images.

The next part of the problem is, because this Java client will be run by several users, I need some way to uniquely identify each uploaded file to the currently logged in user session on the website (the user needs to login on the website, to be able to run the tasks). Any suggestions or more efficient patterns ?

Don't write the stuff to files. Punch the uploaded data into 'raw' database tables by user ID. The batch job job can pull the data out, parse/format/fold/spindle/mutilate, and stuff the results into the real tables, then delete the raw data.