Write the formatting mask with Characters you can use in Java

//  ww  w  .  j  a va2 s. co  m

import java.awt.FlowLayout;
import java.text.ParseException;

import javax.swing.JFormattedTextField;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.text.MaskFormatter;

public class Main {
  public static void main(String args[]) throws ParseException {
    JFrame f = new JFrame();
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setLayout(new FlowLayout());
   
    MaskFormatter mf = new MaskFormatter("A-AAAA-AAAA-A");
    
    JFormattedTextField ftf1 = new JFormattedTextField(mf);
    
    mf.setValueContainsLiteralCharacters(false);
    
    System.out.println(mf.valueToString("123123123123"));
     
    
    f.add(ftf1);
    f.add(new JTextField(5));
    f.setSize(300, 100);
    f.setVisible(true);
  }
}

Character          Description//from ww w  . j  a va 2  s  . c  o  m
#                  Any valid number (Character.isDigit).
'(single quote)    Escape character, used to escape any of the special formatting characters.
U                  Any character (Character.isLetter). All lowercase letters are mapped to uppercase.
L                  Any character (Character.isLetter). All uppercase letters are mapped to lowercase.
A                  Any character or number (Character.isLetter or Character.isDigit).
?                  Any character (Character.isLetter).
*                  Anything.
H                  Any hex character (0-9, a-f or A-F).