Since this looks like a simple program I'd say that you might consider adding two more methods, one for reading from the file and the other for writing to it? Don't see much sense in another helper class for this purpose.
Disagree. File reading is not a responsibility of the Student class, and creating a helper class will make for better design. Also you can reuse the helper class.
But you may find it easier to use a java.util.Scanner for reading and a java.util.Formatter for writing, as long as you don't need to append details to your files.
Change the try-catch to read like thisThe use of "finally" ensures that the reader closes, even when there is an Exception. You need two nested try blocks. Similarly with a writer.
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus