Java Tutorial: Java DateField Validation Source Code

You can validate the textfield for the dateformat(mm/dd/yyyy) with this class module.

Procedure :

1. While declaring textfield in java-swings,(for ex:JTextField txtdate)instead of declaring like above,you can declare like: DateTextField txtdate.

2. Copy the following source code in a notepad and save as DateTextField.java in the location of your java file.

Usage :

You enter the date(for ex:08/25/2005(mm/dd/yyyy)).
if u just enter '08' automatically a '/' adds and after you type '25',automatically '/' addsup.

Then after u finish typing '2005',just press space bar or press any alphabet. It makes a validation on the entered date.

If it finds error,then it deletes the entered date.Then u can enter again the correct date.

Source Code : 'DateTextField.java'

import javax.swing.*;
import javax.swing.text.*;
import javax.swing.event.*;

class DateTextField extends JTextField
{
   protected Document createDefaultModel()
   {
      return new DateDocument(this);
   }

   class DateDocument extends PlainDocument
   {
      JTextField textFld ;
      public DateDocument(JTextField xTextFld)
      {
         textFld = xTextFld;
      }

public void insertString(int offset, String str, AttributeSet a)
         throws BadLocationException
   {
      if(str == null || dateSatisfied(textFld.getText())){
         boolean validity = format(textFld.getText());
         if(validity == false)
         {
JOptionPane.showMessageDialog(null,"Invalid
Entry!!","Alert!",JOptionPane.INFORMATION_MESSAGE);
            textFld.setText(" ");

         }
         else
         return;
      }

      String dateStr       = "";
      char[] inpStr       = str.toCharArray();
      boolean digitAdded = false;
      boolean slashAdded = false;

      for(int i = 0; i < inpStr.length; i++)
      {
         if(Character.isDigit(inpStr[i]))
         {
            digitAdded = true;
            dateStr += String.valueOf(inpStr[i]);
         }
if(inpStr[i] == '/' && slashCountAt(textFld.getText(), 2, offset))
         {
            slashAdded = true;
            dateStr += String.valueOf(inpStr[i]);
         }
      }
      if(offset == 1 && slashAdded == false)
         dateStr += '/';
if(offset == 3 && digitAdded == true && slashCount(textFld.getText(),
1))
         dateStr += '/';
if(offset == 4 && slashAdded == false && slashCount(textFld.getText
(), 1))
         dateStr += '/';
      super.insertString(offset, dateStr, a);
   }

public boolean slashCountAt(String text, int count, int offset)
      {
         boolean matchCount = false;
         if(text != null && !text.equals(""))
         {
            String split[] = text.split("/");
            int splitCount = split.length-1;
            if(splitCount < count){
               if(text.charAt(offset-1) !
= '/')
                  matchCount = true;
         }
         else
               matchCount = false;
         }
         return matchCount;
      }

      public boolean slashCount(String text, int count)
      {
         boolean matchCount = false;
         if(text != null && !text.equals(""))
         {
            String split[] = text.split("/");
            int splitCount = split.length -1;
if(splitCount <= count && text.charAt(text.length()-1) != '/')
               matchCount = true;
         }
         return matchCount;
      }


         public boolean format(String value){

            try{

         int monthindex = value.indexOf("/");
         String month = value.substring(0,monthindex);
               int oldIndex = monthindex;

      int dateindex = value.indexOf("/",monthindex+1);

                        String date = value.substring(oldIndex+1,dateindex);
      String year = value.substring(dateindex+1);

      int monthid = Integer.parseInt(month);
      int idate = Integer.parseInt(date);
      int iyear = Integer.parseInt(year);
      int leapyear = Integer.parseInt(year) % 4;

      if( monthid<13 && monthid>0)
      if(idate<32 && idate>0)
      {
if((monthid == 2 || monthid == 4 || monthid == 6 || monthid == 9 ||
monthid == 11)&&(idate == 31) )

   return false;
if(monthid ==2 && idate > 29)
return false;
if((monthid ==2) &&(idate == 29) && (leapyear!= 0))

   return false;
if((Integer.parseInt(year) < 2010)   && (iyear > 0))

   return true;
   else

   return false;
   }
   else
   return false;
   else
   return false;
         }
            catch(NullPointerException e)
            {
               return false;
            }
            catch(NumberFormatException e)
            {
               return false;
            }
            catch(Exception e)
            {
               return false;
            }
         }


      public boolean dateSatisfied(String text)
      {
         boolean satisfy = false;
         if(text != null && !text.equals(""))
         {
            String split[] = text.split("/");
            int splitCount = split.length -1;
            if(splitCount == 2)
            {
      int slashPos = text.lastIndexOf("/") +1;
      int yearLen    = text.length() - slashPos;
               if(yearLen == 4)
               {
                  satisfy = true;
               }
            }

         }
         return satisfy;
      }//end of dissatisfied
   }
}