I wrote a Address book for practice.
Actually I follow a sample and finally finish. It work fine. It has Add new, Move Next, Move Last, Move First, Clear Buttons. I need to add UPDATE Button. I already Add that button. How can I do the coding?
You ought to separate the logic ("M" for Model) from the class which displays the GUI ("V" for view). I would suggest you have a File object which contains data corresponding to Address objects. Then you can find an Address object, and a way to write it into the file. You would need to find a particular Address object before trying to update it.
Move the clear instructions out of the clear button actionPerformed method into a clearDisplay() method and call clearDisplay() from the actionPerformed method.