Java EE (Java Enterprise Edition) General Discussion

Hi all..

I have an application developed using struts framework. In my application i accept URL from user and
then connect to that URL. After that i retrieve the contents of that URL and do further processing. I have an action class which does these things. I store these processed contents in database along with the URL.
The requirement is that if some other user requests with the same URL in my application, that time already processed data from database shall be used.
As we know web sites keep on modifying its pages from time to time. I want some routine with which i can check if the issued URL ( specific web page ) is actually modified or not. It it is so , i will connect to actual URL and if no then i will use the data already stored in database . Is that possible ?
What are the possible ways to implement the same ?

Can any one have solution in this regard ?

Thanks in advance..
Prasad