使用来自JDialog的JFrame填充JList，类的属性

Question

I have a MainForm class that extends JFrame and has a JList in it.

Now on clicking a button a JDialog pops up, to enter credentials, which in turn downloads a list of values which is to be populated in the Jlist of the parent window.

Now how do I populate my mainForm attribute from my child class ?

MainForm.java

public class MainForm extends JFrame {

static MainForm mainForm;

public static void main(String[] args) {

    SwingUtilities.invokeLater(new Runnable() {
        @Override
        public void run() {
            mainForm = new MainForm();
            mainForm.setVisible(true);
        }
    });
}

    public MainForm() {
               loadUI();
    }

    private void loadUI() {

    JPanel panel = new JPanel();
    getContentPane().add(panel);

            final JList<String> jList = new JList<String>();

            final JButton settings = new JButton(settingImage);
    settings.setBorder(new EmptyBorder(3, 0, 3, 0));
    settings.setBounds(50, 60, 100, 30);
    vertical.add(settings);

    settings.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
             LoginDialog loginDlg = new LoginDialog(mainForm);
             loginDlg.setVisible(true);
             // if logon successfully
             if(loginDlg.isSucceeded()){
                 settings.setText("Hi " + loginDlg.getUsername() + "!");
             }
        }
    });

            add(vertical, BorderLayout.WEST);
    add(jList, BorderLayout.CENTER);

DialogWindow.java

    public LoginDialog(final Frame parent) {
    super(parent, "Login", true);
    //
    JPanel panel = new JPanel(new GridBagLayout());

    //some more lines of code

    btnLogin.addActionListener(new ActionListener() {

        public void actionPerformed(ActionEvent e) {
               ftpAuthenticationVO.setIp(urlIP.getText());
                    ftpAuthenticationVO.setUsername(tfUsername.getText());
                    ftpAuthenticationVO.setPassword(pfPassword.getText());
                    FileUtils.saveFTPDetails(ftpAuthenticationVO);
                    if(ftpConnect.startFTP(CommonConstants.TEMP_TXT_FILE));
                    {
                        List<String> list = readSplitTextFiles.readTextFile(CommonConstants.TEMP_TXT_FILE);
                    //This is the value that is to be populated in the Jlist inside the parent window.  
                    }

Answer 1

Just make your JList as attribute of the MainForm

public class MainForm extends JFrame {

private JList jlist;

.
.
.

private void loadUI() {

    JPanel panel = new JPanel();
    getContentPane().add(panel);

    jList = new JList<String>();

    final JButton settings = new JButton(settingImage);
    settings.setBorder(new EmptyBorder(3, 0, 3, 0));
    settings.setBounds(50, 60, 100, 30);
    vertical.add(settings);
    .
    .
}


public void setJListModel(List<String> list){
   jlist.setModel(new Vector(list));
}

}

And in JDialog

 public void actionPerformed(ActionEvent e) {
               ftpAuthenticationVO.setIp(urlIP.getText());
                    ftpAuthenticationVO.setUsername(tfUsername.getText());
                    ftpAuthenticationVO.setPassword(pfPassword.getText());
                    FileUtils.saveFTPDetails(ftpAuthenticationVO);
                    if(ftpConnect.startFTP(CommonConstants.TEMP_TXT_FILE));
                    {
                        List<String> list = readSplitTextFiles.readTextFile(CommonConstants.TEMP_TXT_FILE);
 (MainForm)parent.setJListModel(list);
                    }

Also parent must be declared as final .