Without background on the webserver capabilities or if you want to hardcode such into Java I can see some hundred solutions. Nothing specific as to what your answer will be since I don't know if you do CGI, Java or "other."
Before I write further, my policy is I don't write code for non-GNU projects for other people unless they pay me. So don't ask for code.
I will however supply fishing lessons and directions, but no "fish."
With that disclaimer, look at a prime example of how some swap BANNER ADS?
I want to be able to show a picture on a website. But I also want that picture to change on the website depending on the ip address of the viewer.
Ex: House 1 viewing the website would see Pic 1
House 2 viewing the same website would see Pic 2.
Any help would be appreciated.