JFrame On Close Operation

Question

I was wondering if there is a way, by clicking on the "X", to let the program perform some code before closing the JFrame. The setDefaultCloseOperation() method takes only an integer.

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

Venturesome

Answer 1

You might be interested in using a WindowListener. The WindowListener tutorial.

Temperament

Thank you, very much. Thats just what im after. – Venturesome

Or you can use WindowAdapter as convenience for creating listener objects. – Bullock

Answer 2

this.addWindowListener(new WindowAdapter(){
                public void windowClosing(WindowEvent e){
                    int i=JOptionPane.showConfirmDialog(null, "Seguro que quiere salir?");
                    if(i==0)
                        System.exit(0);//cierra aplicacion
                }
            });

Cathexis

Answer 3

@Jeffrey has a good answer, but you should consider what you're trying to do. If you really want to do something upon the closing of a frame, then a WindowListener is the way to go. However, if you're looking for a place to do some cleanup and graceful shutdown stuff, then you probably want a shutdown hook instead. Using a WindowListener, the code will only be triggered, as you said, by the user "clicking on the X". But what if the user starts the app in the foreground of a terminal and kills it with Ctrl+C? What if the user kills the process from the command line or from a task manager?

Guenna

Wow, thank you for you reply. Im using this to save some data upon closing the frame. – Venturesome

@Sanjay: I chose to link jdk6 because 1) in my experience, more people are still using 6 than 7, and 2) Runtime.addShutdownHook() didn't change a lick between 6 and 7. – Guenna

okay,point taken :) but I usually prefer to link to the latest docs whatsoever ! – Lennon