public void mostrarNotificacion(Usuario user) throws AWTException, java.net.MalformedURLException, IOException {
    //Obtain only one instance of the SystemTray object
    SystemTray tray = SystemTray.getSystemTray();

    //Get image
    BufferedImage trayIconImage = ImageIO.read(getClass().getResource("favicon.png"));
    int trayIconWidth = new TrayIcon(trayIconImage).getSize().width;
    TrayIcon trayIcon = new TrayIcon(trayIconImage.getScaledInstance(trayIconWidth, -1, Image.SCALE_SMOOTH));

    //Let the system resizes the image if needed
    trayIcon.setImageAutoSize(true);

    //Set tooltip text for the tray icon
    if(user.getDescargos()>=5 || user.getOtrosPendientes()>=1){
        mensaje = "Descargos pendientes: " + user.getDescargos() + "nSecciones pendientes: "+ user.getOtrosPendientes();
    }
    trayIcon.setToolTip(mensaje);
    tray.add(trayIcon);
    trayIcon.displayMessage("Pendientes EKHI", mensaje, MessageType.WARNING);
}