it already uses apache, just look at the documentation...

Already read the documentation
It may be using a apache  but a light version only, for example it supports
limited security features. Thats why I want to use an apache web  server as a
reverse proxy in front of my oc4j.

My problem was that I have never used apached before and I had zero
configuration experience. But searched a little bit and solved my problem, I
used the mod_proxy apache module.