How to call function on menu item click?

Question

I am developing an application.

I am trying to call a method on menu item click, but how to call it I don't know.

My menu code is as follow:

JMenuBar menuBar = new JMenuBar();
setJMenuBar(menuBar);

JMenu mnFile = new JMenu("File");
menuBar.add(mnFile);

JMenuItem mntmLoadImage = new JMenuItem("Load Image");
mnFile.add(mntmLoadImage);

JMenuItem mntmSaveImage = new JMenuItem("Save Image",s.save("/images", ""));
mnFile.add(mntmSaveImage);

JSeparator separator = new JSeparator();
mnFile.add(separator);

JMenuItem mntmExit = new JMenuItem("Exit");
mnFile.add(mntmExit);

JMenu mnEdit = new JMenu("Edit");
menuBar.add(mnEdit);

JMenuItem mntmIncreaseBright = new JMenuItem("Increase Bright");
mnEdit.add(mntmIncreaseBright);

JMenuItem mntmDecreaseBright = new JMenuItem("Decrease Bright");
mnEdit.add(mntmDecreaseBright);

JSeparator separator_1 = new JSeparator();
mnEdit.add(separator_1);

JMenuItem mntmRestoreImage = new JMenuItem("Restore Image");
mnEdit.add(mntmRestoreImage);

JMenu mnHelp = new JMenu("Help");
menuBar.add(mnHelp);

JMenuItem mntmHelpCtrl = new JMenuItem("Help ctrl + K");
mnHelp.add(mntmHelpCtrl);

JMenuItem mntmAboutImageEditor = new JMenuItem("About Image Editor");
mnHelp.add(mntmAboutImageEditor);

JSeparator separator_2 = new JSeparator();
mnHelp.add(separator_2);

JMenuItem mntmAboutCompany = new JMenuItem("About Company");
mnHelp.add(mntmAboutCompany);

My function code is as follow:

public void save(String path, String name) throws IOException {
    if (scaled != null) {  
        name += scaled.getWidth() + "x" + scaled.getHeight();
        ImageIO.write(scaled, "png", (ImageOutputStream) new File(path + File.separator + name + ".png"));
    } else {
        throw new NullPointerException("Scaled instance is null");
    }
}

I am calling function in save image menu item but its shows an error. here s is object of class in which I have define method save.

Answer 1

mntmSaveImage.addActionListener(new ActionListener(){
  public void actionPerformed(ActionEvent e){
    // get the path and the name
    save(path, name);
  }
});

Maybe a JFileChooser will be useful to get the path and the name, here is a little sample :)

JFileChooser chooser = new JFileChooser();
int returnVal = chooser.showOpenDialog(parent);
if(returnVal == JFileChooser.APPROVE_OPTION) {
   path = chooser.getSelectedFile().getAbsolutePath();
   name = chooser.getSelectedFile().getName();
}

If I don't say some mistake, parent is your Container such as a JFrame.
Hope it helps !