How to autopress button in another Java app?

Question

My mainapp should automatically press a "login" or "yes" button from another application.
In my mainapp I have:
private Toolkit toolkit = Toolkit.getDefaultToolkit();
toolkit = toolkit.addAWTEventListener(new LookForLoginOrYes, AWTEvent.WINDOW_EVENT_MASK);
public static class LookForLoginOrYes implements AWTEventListener {
   public void eventDispatched (AWTEvent event) {
      System.out.println("in LookFor..."+event.toString()); // this line is printed out!
      WindowEvent windowEvent = (WindowEvent) event;
      if (event.getID() == WindowEvent.WINDOW_OPENED) {
         System.out.println("LFA: WindowEvent.WINDOW_OPENED"); // this line is never printed
         Window window = windowEvent.getWindow();
         if (window instanceof Frame) {
            System.out.println("LFA: " + ((Frame) window).getTitle()); // never printed
}line with event.toString() displays that my mainapp has no focus anymore of has focus (for this I replaced WINDOW_EVENT_MASK with ~0L).
Clicking on the titlebar or so of the second app (with the 'yes' button) nothing happens.
Security settings?

Answer 1

The Robot class ties into the native interface, but has no concept of the application's components. Therefore, the only way the Robot class could perform this task is if a) you teach it to recognize the button from a screenshot of the desktop or b) you guarantee that the button is in a specific location. The Robot class is the only system-independent way to do this if your applications run in different JVMs. This is because each JVM is pretty much a seperate computer and, beyond network connections, file pipes, etc., each has no concept of the other's existence.
Are you able to modify both applications' source? If so, I would recommend you handle your situation this way:
public class AppOne extends JFrame
    public AppOne(...)
        JButton button = new JButton("That Button You Want To Press");
        button.addActionListener(new ActionListener()
            public void actionPerformed(ActionEvent e)
                thatButtonWasPressed();
    public void thatButtonWasPressed()
        ... // button-press code
    public static void main(String arg[])
        AppOne app = new AppOne(...);
        app.setLocationRelativeTo(null);
        app.setVisible(true);
public class AppTwo extends JFrame
    public AppTwo(AppOne other_app, ...)
        ... // at the appropriate point, call "other_app.thatButtonWasPressed()"
    public static void main(String arg[])
        AppOne app_one = new AppOne(...);
        AppTwo app_two = new AppTwo(app_one, ...);
        app_one.setLocationRelativeTo(null);
        app_one.setVisible(true);
        app_two.setLocationRelativeTo(null);
        app_two.setVisible(true);
}In this example, the button is not actually being pressed, but the same effect is generated. I recommend this approach because it cuts out a lot of potential interference. Why deal with the user interface if you don't have to? What you seem to want (and correct me if I'm wrong) is for the application to perform a specific operation on your request. The fact that this operation happens to also occur when a user presses a specific button is irrelevant.
Is there some reason you need the Swing/AWT system to actually think the button has been pressed? If you can't modify the source code of the one application, that would make sense.