How to restrict Date field entered in a text field should be of MM/dd/yyyy

Question

Hi,
I have an text field for Date entry,the Date format is MM/dd/yyyy,while entering the value i want to verify wether the values entered are valid or not,like month should n't be more than 12,date value depends on month should not exceed 30,31 or 28,year should not exceed 9999 like,if not possible at the time of entery i want to stop at least before submission.Right now i am traing to use my own model which extends PlainDocument calss,
as in the fallowing way.But i t could not stop me to enter the wrong values ,Any help would be appreciated.
mport javax.swing.text.PlainDocument;
import javax.swing.text.AttributeSet;
import javax.swing.text.Document;
import javax.swing.text.BadLocationException;
import java.awt.Toolkit;
* Insert the type's description here.
* Creation date: (11/26/2001 6:22:14 PM)
* @author: Administrator
class DateFormatDocument extends javax.swing.text.PlainDocument {
* DateFormatDocument constructor comment.
String sInputMask;     DateFormatDocument(){
//     sInputMask="MM/dd/yyyy";
          sInputMask="09/30/2000";
try{
//     insertString(0,"MM/dd/yyyy",null);
     insertString(0,"09/30/2000",null);
     }catch(BadLocationException ex){System.err.println(ex);}
public void insertString(int offs,String str,AttributeSet a) throws BadLocationException{
     String sText=super.getText(0,getLength());
     if(sText.length()==0)
          super.insertString(offs,str,a);
          return;
     int len=str.length();
     String sText1 = super.getText(0,2);String sText2 = super.getText(3,5);String sText3 = super.getText(6,10);
     int str1=Integer.parseInt(sText1);int str2=Integer.parseInt(sText2);int str3=Integer.parseInt(sText3);
//     System.out.println("str1:"+str1);
     if(offs<2 && str1<=12){
     if(len<=2){
               super.remove(offs,len);
               super.insertString(offs,str,a);
     else if(offs==2){
          super.remove(offs,1);
          super.insertString(offs,"/",a);
     else if(offs<5 && str2<=30){
          if(len<=2){
               super.remove(offs,len);
               super.insertString(offs,str,a);
     else if(offs==5)
          super.remove(offs,1);
          super.insertString(offs,"/",a);
     else if(offs<10 && str3<=9999 ){
          if(len<=4){
               super.remove(offs,len);
               super.insertString(offs,str,a);
     else{
          System.err.println("Beep!");
          //Toolkit.beep();
public void remove(int offs,int len) throws BadLocationException{
     System.err.println(offs + " " + len);
     if(offs<2){
          if(len==1){
               super.remove(offs,len);
               super.insertString(offs," ",null);
          else if(len==2){
               super.remove(offs,len);
               super.insertString(offs," ",null);
     else if(offs==2){
          //do nothing
     else if(offs<5){
          if(len==1){
               super.remove(offs,len);
               super.insertString(offs," ",null);
          else if(len==2){
               super.remove(offs,len);
               super.insertString(offs," ",null);
     else if(offs<10){
          if(len==1){
               super.remove(offs,len);
               super.insertString(offs," ",null);
          else if(len==2){
               super.remove(offs,len);
               super.insertString(offs," ",null);
          else if(len==3){
               super.remove(offs,len);
               super.insertString(offs," ",null);
          else if(len==4){
               super.remove(offs,len);
               super.insertString(offs," ",null);
}

Answer 1

<code>
mport javax.swing.text.PlainDocument;
import javax.swing.text.AttributeSet;
import javax.swing.text.Document;
import javax.swing.text.BadLocationException;
import java.awt.Toolkit;
* Insert the type's description here.
* Creation date: (11/26/2001 6:22:14 PM)
* @author: Administrator
class DateFormatDocument extends javax.swing.text.PlainDocument {
* DateFormatDocument constructor comment.
String sInputMask; DateFormatDocument(){
// sInputMask="MM/dd/yyyy";
sInputMask="09/30/2000";
try{
// insertString(0,"MM/dd/yyyy",null);
insertString(0,"09/30/2000",null);
}catch(BadLocationException ex){System.err.println(ex);}
public void insertString(int offs,String str,AttributeSet a) throws BadLocationException{
String sText=super.getText(0,getLength());
if(sText.length()==0)
super.insertString(offs,str,a);
return;
int len=str.length();
String sText1 = super.getText(0,2);String sText2 = super.getText(3,5);String sText3 = super.getText(6,10);
int str1=Integer.parseInt(sText1);int str2=Integer.parseInt(sText2);int str3=Integer.parseInt(sText3);
// System.out.println("str1:"+str1);
if(offs<2 && str1<=12){
if(len<=2){
super.remove(offs,len);
super.insertString(offs,str,a);
else if(offs==2){
super.remove(offs,1);
super.insertString(offs,"/",a);
else if(offs<5 && str2<=30){
if(len<=2){
super.remove(offs,len);
super.insertString(offs,str,a);
else if(offs==5)
super.remove(offs,1);
super.insertString(offs,"/",a);
else if(offs<10 && str3<=9999 ){
if(len<=4){
super.remove(offs,len);
super.insertString(offs,str,a);
else{
System.err.println("Beep!");
//Toolkit.beep();
public void remove(int offs,int len) throws BadLocationException{
System.err.println(offs + " " + len);
if(offs<2){
if(len==1){
super.remove(offs,len);
super.insertString(offs," ",null);
else if(len==2){
super.remove(offs,len);
super.insertString(offs," ",null);
else if(offs==2){
//do nothing
else if(offs<5){
if(len==1){
super.remove(offs,len);
super.insertString(offs," ",null);
else if(len==2){
super.remove(offs,len);
super.insertString(offs," ",null);
else if(offs<10){
if(len==1){
super.remove(offs,len);
super.insertString(offs," ",null);
else if(len==2){
super.remove(offs,len);
super.insertString(offs," ",null);
else if(len==3){
super.remove(offs,len);
super.insertString(offs," ",null);
else if(len==4){
super.remove(offs,len);
super.insertString(offs," ",null);
</code>