Request and session objects in webdynpro

Hi

I am a pure java developer.

My manager has asked me to make an application (simple RFC call) in webdynpro java.

I followed some documents and it was easy to finish task...

But I was thinking to make an application now which can read contents from a CSV file and insert that in value attribute nodes.

I am having an action button.

A function which will be invoked from that button.

Now how can i do it.....means the best approach.

shall i create a separate class somewhere in my application and make an object of that class in onAction function of my button !!!

Or do i have to write entire code in onAction function.

Does concept of separate classes, request objects and session exist in webdynpro...!!

Because wen i did that RFC call everything was self created....!!

Please comment.

Thanks.