Clearing a JPanel

Question

I have been programming a diary but i have been having a problem... The program when it loads gets every file from the folder saved and then makes a button for each one and adds an actionListener. It works fine( the program loads and shows the buttons[they work too]) but when the user makes a new file and saves it i want it to update the filebar so i made a method that is called update that updates the filbar (which i call at the booting of the program). The problem is that when a new file is made update is called but no changes are made to the filbar. Here is the update methods code:
public Document getDocument(String name) {
            try     {
          DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
          factory.setIgnoringComments(true);
          factory.setIgnoringElementContentWhitespace(true);
          factory.setValidating(true);
          DocumentBuilder builder = factory.newDocumentBuilder();
          return builder.parse(new InputSource(name));
            } catch (Exception e) {
                JOptionPane.showMessageDialog(null, "Error reading config.xml\nError #: ", "ERROR", JOptionPane.WARNING_MESSAGE);
            return null;
        public void update() {
            for(int x = 0; x < btn.length; x++) {
                btn[x] = new JButton(dirs[x]);
                filepane.add(btn[x]);
                final int bnum = x;
                btn[x].addActionListener(new ActionListener(){
                    public void actionPerformed(ActionEvent ae){
                        String fi = btn[bnum].getLabel();
                        try {
                            BufferedReader filein = new BufferedReader(new FileReader("saved/" + fi));
                            String fin;
                            note.setText("");
                            name.setText(fi);
                            setTitle("Diary 2.00: " + fi);
                            fin = filein.readLine();
                            String decrypted = decrypt(fin);
                            note.setText(decrypted);
                        catch (FileNotFoundException ioe) {
                            JOptionPane.showMessageDialog(null, "Can not find the file\nError #: 5", "ERROR", JOptionPane.WARNING_MESSAGE);
                        } catch (NullPointerException ioe) {
                            JOptionPane.showMessageDialog(null, "The document contains no data", "ERROR", JOptionPane.WARNING_MESSAGE);
                        catch (IOException ioe) {
                            JOptionPane.showMessageDialog(null, "Internal Error\nError #: 4", "ERROR", JOptionPane.WARNING_MESSAGE);
Thank you for your help!!

Answer 1

I don't see where you are telling the filepane that it needs to update itself after you have added your button. I would hope that you're using a suitable layout for filepane (boxLayout sounds like a good fit at first glance). Try the following...
filepane.add(btn[x]);
filepane.validate();
filepane.repaint(); //I can't remember if validate or repaint will get it to refresh, maybe both?Also, unless you're resetting the contents of the filepane, it looks like you're going to be adding all the buttons each time update is called. That probably isn't good.