Hi, welcome to the ranch!
HTTP has a IF-MODIFIED-SINCE header. If the resource you request is not newer than the date you give,
you should get back a 304 return code for not modified. You should be able to add this header to your HTTPUrlConnection.
From your subject, it sounds like that's what you're trying to use. What do you have that's not working? Feel welcome to post small snippets of code if you have narrowed the problem down. Be sure to look into the "CODE" button while entering your post.
The
W3C Site is an thorough (if a bit hard to read) source for HTTP stuff.
[ July 10, 2005: Message edited by: Stan James ]