Question

I am making a word processor application in order to practise Java and I would like it so that when the user attempts to close the appliction, a JFrame will come up asking to save changes.

I was thinking about setDefaultCloseOperation() but I have had little luck so far. I would also like it to appear whent he user clicks the “X” on the top right of the window aswell if possible.

Answer 1

You can set the JFrame DefaultCloseOperation to something like DO_NOTHING, and then, set a WindowsListener to grab the close event and do what you want. I’ll post an exemple in a few minutes .

EDIT: Here’s the example :

public static void main(String[] args) {
        final JFrame frame = new JFrame("Test Frame");

        frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);

        frame.setSize(800, 600);

        frame.addWindowListener(new WindowAdapter() {
            //I skipped unused callbacks for readability

            @Override
            public void windowClosing(WindowEvent e) {
                if(JOptionPane.showConfirmDialog(frame, "Are you sure ?") == JOptionPane.OK_OPTION){
                    frame.setVisible(false);
                    frame.dispose();
                }
            }
        });

        frame.setVisible(true);
    }