search results with servlet or JSP

i'm working on a website for online advertising where you put your advertisement and you can search for other's advertisements. But, here is my problem: when u search for advertisements in the website, the advertisements should show up in some table form with a little description and their small size picture along, and when u click on any advertisement u should see the pic with a larger size and the description of the advertisment saved in the database. BUT, i dont know how to do such a thing, do i have to take each picture and resize it to a thumbnail size and have another copy of the pic with the original size? or is there any another solution. I would be very thankful if anyone could help me in this.

Well, here is something, it is not exactly what you are looking for, but it might help you out.

http://schmidt.devlib.org/java/save-jpeg-thumbnail.html

What it does is scale an image into a thumbnail and save it into another file, you can omit the second part and just show the image. Hope it helps....