To fix the length of a textfield for user to enter date

Question

hi,
i need to display a textfield for user to enter the date in the format MM/DD/YY.With the slash in between present and fixed and the possibility of entering only 2 digit figures for the month,day n' year.I am using JTextField .how can i acheive that pls help.

Answer 1

You must design you own document where you will manage the text that will be entered/displayed in your textfield
here's a sample of the code I use to do this:
import javax.swing.JTextField;
import java.io.*;
import javax.swing.*;
import javax.swing.text.*;
import java.awt.*;
import java.awt.event.*;
public class MaskedTextField extends JTextField
private String initStr;
public MaskedTextField (String mask, String initStr)
super();
setDocument(new MaskedDocument(initStr, mask, this));
setText(initStr);
this.initStr = initStr;
this.addMouseListener(new java.awt.event.MouseAdapter()
public void mouseClicked(MouseEvent m)
this_mouseClicked(m);
private void this_mouseClicked(MouseEvent m)
if (getText().equals(initStr)) setCaretPosition(0);
class MaskedDocument extends PlainDocument
String mask;
String initStr;
JTextField tf;
public MaskedDocument(String initStr, String mask,
MaskedTextField container)
this.mask = mask;
this.initStr = initStr;
tf = container;
void replace(int offset, char ch, AttributeSet a)
throws BadLocationException
super.remove(offset,1);
if (capitalised) super.insertString(offset,
String.valueOf(ch).toUpperCase(),a);
else super.insertString(offset, "" + ch, a);
public void remove(int offs, int len) throws BadLocationException
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
if (str.charAt(i) != this.initStr.charAt(i))
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;
else
i++;
offset--;
// Skip over "fixed" characters
offset += str.length();
while ((offset<mask.length()) && (mask.charAt(offset)=='-'))
offset++;
if (offset<mask.length())
tf.setCaretPosition(offset);
if (offset == mask.length()) tf.setCaretPosition(offset);
Enjoy
Bernie