Problem with a mask in a JFormattedTextField

Question

I am tring to create a text box with a mask.
This object text box is declared like a class var.
I have another object, a mask object that is also declared as a class var
but I cant create this mask. The errors are commented,
if you erase the comments and create the class you are going to see the error.
javac ContraBase.java
java ContraBase
Estoy tratando de crear un campo de texto con mascara.
este objeto texto esta definico como variable de clase
tengo definida una mascara tambien como variable de clase
Pero no me deja crear la mascara. Los errores estan comentados,
si quita los comentados y crea el class vera el problema.
javac ContraBase.java
java ContraBase
import java.sql.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
import javax.swing.JFormattedTextField;
class ContraBase extends JPanel
     //MaskFormatter mascara1 = new MaskFormatter("########"); //aca se produce un error
     //JFormattedTextField PRECIOA = new JFormattedTextField (mascara1); //la idea es definir aca la mascara
     JFormattedTextField PRECIOA = new JFormattedTextField ("########");
     public ContraBase()
          //TEXTBOX
          PRECIOA.setToolTipText("PRECIOA");
          add(PRECIOA);
     static public void main (String[] args)
          System.out.println("Iniciando programa.");
          try
               JFrame VentanaPrincipal = new JFrame("Practicas con Java, trabaja con Base");
               VentanaPrincipal .setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
               VentanaPrincipal .getContentPane().add(new ContraBase(), BorderLayout.CENTER);
               VentanaPrincipal .setSize(350,500);
               VentanaPrincipal .setVisible(true);
          catch(Exception e)
               System.out.println("****INGRESA A EXCEPTION main****");
               System.out.println(e.toString());
               System.out.println("****SALE DE EXCEPTION main****");
               return;
          System.out.println("Creacion Finalizada.");
}

Answer 1

Sounds like that field is editable. The renderer renders the display when a field is not
being edited, a TableCellEditor is in charge when the field is edited, and the default
editor is just a JTextField.
: jay