How do I bring a window to the front from a different VM ?

Question

The problem I am facing is as follows:
We have an application the loads a plugin which the starts another VM. This VM has some UI components as does the initial VM. I need to be able to bring a window from either VM to the front. It appears that Windows 2000 doesn't allows this.
Any ideas ???
Here is some sample code. Run it twice so you get two VMs.
Thanks
Olaf
-----------Frame1.java---------------------
package showwindow;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Frame1 extends JFrame {
JPanel contentPane;
BorderLayout borderLayout1 = new BorderLayout();
JButton jButton1 = new JButton();
//Construct the frame
public Frame1() {
enableEvents(AWTEvent.WINDOW_EVENT_MASK);
try {
jbInit();
catch(Exception e) {
e.printStackTrace();
//Component initialization
private void jbInit() throws Exception {
contentPane = (JPanel) this.getContentPane();
jButton1.setText("jButton1");
contentPane.setLayout(borderLayout1);
this.setSize(new Dimension(400, 300));
this.setTitle("Frame Title");
contentPane.add(jButton1, BorderLayout.CENTER);
//Overridden so we can exit when window is closed
protected void processWindowEvent(WindowEvent e) {
super.processWindowEvent(e);
if (e.getID() == WindowEvent.WINDOW_CLOSING) {
System.exit(0);
-----------Application1.java---------------
package showwindow;
import javax.swing.UIManager;
import java.awt.*;
import java.awt.Window;
public class Application1 {
boolean packFrame = false;
Frame1 frame;
//Construct the application
public Application1() {
frame = new Frame1();
//Validate frames that have preset sizes
//Pack frames that have useful preferred size info, e.g. from their layout
if (packFrame) {
frame.pack();
else {
frame.validate();
//Center the window
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
Dimension frameSize = frame.getSize();
if (frameSize.height > screenSize.height) {
frameSize.height = screenSize.height;
if (frameSize.width > screenSize.width) {
frameSize.width = screenSize.width;
frame.setLocation((screenSize.width - frameSize.width) / 2, (screenSize.height - frameSize.height) / 2);
frame.setVisible(true);
public Frame1 getFrame()
return frame;
//Main method
public static void main(String[] args) {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
catch(Exception e) {
e.printStackTrace();
Application1 app = new Application1();
while(true)
app.getFrame().toFront();
try
Thread.currentThread().sleep(2000);
catch(Exception e)

Answer 1

From the j2sdk 1.4.1 API: http://java.sun.com/j2se/1.4.1/docs/api/java/awt/Window.html#toFront()
toFront()
Some platforms do not allow Windows which own other Windows to appear on top of those owned Windows. Some platforms may not permit this VM to place its Windows above windows of native applications, or Windows of other VMs. This permission may depend on whether a Window in this VM is already focused. Every attempt will be made to move this Window as high as possible in the stacking order; however, developers should not assume that this method will move this Window above all other windows in every situation.
Because of variations in native windowing systems, no guarantees about changes to the focused and active Windows can be made. Developers must never assume that this Window is the focused or active Window until this Window receives a WINDOW_GAINED_FOCUS or WINDOW_ACTIVATED event. On platforms where the top-most window is the focused window, this method will probably focus this Window, if it is not already focused.