how to read a file from response object

I have servlet response object which file(allowable format).Now I want to read the file from response Object and save that file in some location of my computer. How It can be done. If possible give some pseudo code??

You set that file in the response, so you already have reference to it, moreover its present on your hard drive or a location accessible to you.
I am not getting what you are trying to do here.