You may use [font=courier new]application[/font] instead of [font=courier new]session[/font] in [font=courier new]readHome.jsp[/font], [font=courier new]writeHomeEdits.jsp[/font] and [font=courier new]closeHome.jsp[/font]. It's used to store the reference copy of the edited file, so there's no risk that some conflicts happen here.
But if there's more than a user in your application, you'll have to manage session somewhere in case you don't want a user to edit the files of other users.