Create a pop-up baloon in the system tray

public class SysTray {
public static void main(String[] args) throws Exception {
TrayIcon icon = new TrayIcon(getImage(), "Java application as a tray icon",
createPopupMenu());
icon.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(null, "Hey, you activated me!");
}
});
SystemTray.getSystemTray().add(icon);

Thread.sleep(3000);

icon.displayMessage("Attention", "Please click here",
TrayIcon.MessageType.WARNING);
}

private static Image getImage() throws HeadlessException {
Icon defaultIcon = MetalIconFactory.getTreeHardDriveIcon();
Image img = new BufferedImage(defaultIcon.getIconWidth(),
defaultIcon.getIconHeight(), BufferedImage.TYPE_4BYTE_ABGR);
defaultIcon.paintIcon(new Panel(), img.getGraphics(), 0, 0);

return img;
}

private static PopupMenu createPopupMenu() throws HeadlessException {
PopupMenu menu = new PopupMenu();

MenuItem exit = new MenuItem("Exit");
exit.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
menu.add(exit);

return menu;
}
}