Formatting a textfield

Question

I would like to format a text field to accept a phone number eg (***) *** - ****
How do I create this mask?
I have seen JMaskField mentioned but I can not find any examples. Could anyone provide an example of how to use JMaskField or have you got any other suggestions?
Thank you

Answer 1

hi soughtred,
Try the following code. I hope this is what you want.
import java.io.*;
import javax.swing.*;
import javax.swing.text.*;
import java.awt.*;
import java.awt.event.*;
class MaskedTextField extends JTextField {
public MaskedTextField (String mask, String initStr) {
super();
setDocument(new MaskedDocument(initStr, mask, this));
setText(initStr);
setColumns(mask.length()+1);
class MaskedDocument extends PlainDocument {
String mask;
String initStr;
JTextField tf;
public MaskedDocument(String initStr, String mask, JTextField container) {
this.mask = mask;
this.initStr = initStr;
tf = container;
void replace(int offset, char ch, AttributeSet a)
throws BadLocationException {
super.remove(offset,1);
super.insertString(offset,""+ch,a);
public void remove(int offs, int len) throws BadLocationException {
System.out.println("R:"+len+","+offs);
if (len==0)
return;
// Remove current contents
super.remove(offs, len);
// Replace the removed part by init string
super.insertString(offs,initStr.substring(offs,offs+len),
getAttributeContext().getEmptySet());
tf.setCaretPosition(offs);
public void insertString(int offset, String str, AttributeSet a)
throws BadLocationException {
if ((offset==0) && str.equals(initStr)) {
// Initialisation of text field
super.insertString(offset,str,a);
return;
if (str.length()==0) {
super.insertString(offset,str,a);
return;
for (int i=0;i<str.length();i++) {
while ((offset+i) < mask.length()) {
if (mask.charAt(offset+i)=='-')
// Skip fixed parts
offset++;
else {
// Check if character is allowed according to mask
switch (mask.charAt(offset+i)) {
case 'D': // Only digitis allowed
if (!Character.isDigit(str.charAt(i)))
return;
break;
case 'C': // Only alphabetic characters allowed
if (!Character.isLetter(str.charAt(i)))
return;
break;
case 'A': // Only letters or digits characters allowed
if (!Character.isLetterOrDigit(str.charAt(i)))
return;
break;
replace(offset+i, str.charAt(i),a);
break;
// Skip over "fixed" characters
offset += str.length();
while ((offset<mask.length()) && (mask.charAt(offset)=='- ')) {
offset++;
if (offset<mask.length())
tf.setCaretPosition(offset);
public class test {
public static void main(String[] args) {
final JFrame f = new JFrame("Textfield demo");
f.setDefaultCloseOperation(f.DISPOSE_ON_CLOSE);
f.addWindowListener(new WindowAdapter() {
public void windowClosed(WindowEvent e) {
System.exit(0);
f.setSize(250,70);
MaskedTextField tf=new MaskedTextField("DD-D-D-DDD-DDDD","..-
tf.setFont(new Font("Monospaced", Font.BOLD, 14));
JPanel panel = new JPanel();
panel.add(tf);
f.getContentPane().add(panel);
f.setVisible(true);