import  javax.swing.JTextField;
 import  javax.swing.text.*;

 public   class  IntegerEditTextField  extends  JTextField
{
   public  IntegerEditTextField()
  {
     super ();
  }

   public  Integer getValue()
  {
    Integer res =  null ;
     try 
    {
      res = Integer.valueOf( this .getText());
    }
     catch (NumberFormatException e)
    {
    }
     return  res;
  }

   public   void  setValue(Integer value)
  {
     this .setText(value ==  null  ? "" : value.toString());
  }

   protected  Document createDefaultModel()
  {
     return   new  IntegerTextDocument();
  }

   protected   class  IntegerTextDocument  extends  PlainDocument
  {
     public   void  insertString( int  offs, String str, AttributeSet a)  throws  BadLocationException
    {
      String insertStr = str.trim();
      String currentText = getText( 0 , getLength());
      String beforeOffset = currentText.substring( 0 , offs);
      String afterOffset = currentText.substring(offs, currentText.length());
      String proposedResult = beforeOffset + insertStr + afterOffset;

       if  (proposedResult.length() ==  0 )
         super .insertString(offs, insertStr, a);
       else 
      {
         try 
        {
          Integer.valueOf(proposedResult);
           super .insertString(offs, insertStr, a);
        }
         catch (NumberFormatException e)
        {
        }
      }
    }

     public   void  remove( int  offs,  int  len)  throws  BadLocationException
    {
      String currentText = getText( 0 , getLength());
      String beforeOffset = currentText.substring( 0 , offs);
      String afterOffset = currentText.substring(len + offs, currentText.length());
      String proposedResult = beforeOffset + afterOffset;

       if  (proposedResult.length() ==  0 )
         super .remove(offs, len);
       else 
      {
         try 
        {
          Integer.valueOf(proposedResult);
           super .remove(offs, len);
        }
         catch (NumberFormatException e)
        {
        }
      }
    }
  }
}