Storing images in a db (for web/midlet access)

Hi All,
So I am trying to store images in the db which will be accessed from
a midlet and website.
So I looked into generating temp files, such as the one done here
using servlets (http://fdegrelle.over-blog.com/categorie-275139.html)
What I am confused about is that this may not be very efficient.
When one browses a website, the pages (and hence the images) are
basically cached in the browser, but with this method, it seems that
every access to an image (that has already been viewed in a web
session) is going to cause a re-query to the database. Not that
efficient, no?
Is there another way around that will help me take advantage of
caching etc, just like it would with storing images on fs?
Much thanks in advance!

-Assad