A good solution to this would be to store all of your GUI components in an ArrayList or some other sort of List that you may prefer.
You would initially read the text file and add it's respective components into the list, and then you would load that list into your GUI. When the file is edited, you can loop through it again and if a component does not exists in the list you can add it in. If any components in the list don't correspond to the file you can remove them from the list. After that happens, you can reload the GUI with the components in the list.