Problem making text JUnit in textsfield

Good, I have a question for a test in JUnit . I do not know how to perform a test in my code that tells me that they can only enter a number in my textfield. I pass the code of what I have done.

@Test

public void testHandleSalir() throws Exception {
    System.out.println("handleSalir");
    ActionEvent event = null;
    vistaController instance = new vistaController();
    instance.handleSalir(event);
    // TODO review the generated test code and remove the default call to fail.
    fail("The test case is a prototype.");
}

/**
 * Test of inicializarTabla method, of class vistaController.
 */
@Test
public void testInicializarTabla() {
    System.out.println("inicializarTabla");
    vistaController instance = new vistaController();
    instance.inicializarTabla();
    // TODO review the generated test code and remove the default call to fail.
    fail("The test case is a prototype.");
}

/**
 * Test of initialize method, of class vistaController.
 */
@Test
public void testInitialize() {
    System.out.println("initialize");
    URL url = null;
    ResourceBundle rb = null;
    vistaController instance = new vistaController();
    instance.initialize(url, rb);
    // TODO review the generated test code and remove the default call to fail.
    fail("The test case is a prototype.");
}

Now I have to validate only in the note textfiel that only numbers are integrated:

 private void actualizartxfNota(String text){
      if((Integer.parseInt(txfNota.getText())>0)&&
(Integer.parseInt(txfNota.getText())<=10)){

        }
            else{

                System.out.println("BtAbrirDialogo ActionEventHandler");

            // Creamos un tipo de dialog Alerta
            Alert alert = new Alert(AlertType.ERROR);

            // Establecemos el título
            alert.setTitle("Diálogo de alerta");

            // Establecemos el texto que aparece en la cabecera
            alert.setHeaderText("Alerta");

            // Establecemos el título que aparece en el cuerpo del diálogo
            alert.setContentText("Introducir numero del 0 al 10");

            // Mostramos el diálogo
            alert.show();
            txfNota.setText("");
            }
}

Thanks and best regards