Random Access File

Hai..
i need to ask a question regarding random access file...
Currently im doing a project on a simple accounting software about a club.
The problem is right now, is that i need to do a summation of balance(Grand Total).
Hence, how do i do a summation of random access file..firstly, is it possible to do?
secondly, if it is possible,how should i do it? Is there any different coding that i have to know.
There is only one column for balance where i need to add all of them up to get the Grand Total, but then all the values are prompt.
I really hope you can figure out the solution to this..
Thank you..

Firstly, yes. It is very possible if you know how the file is structured. See this link for how to access random access files with java. Could you tell us the data structure of the file, possibly post an example?