Please see the FAQ.
thanks but in faq, it just shows me how to setup web application under jboss and tells me the detail about the port, location etc.
I can not find anything about the how to disable jetty.
Maybe next time look a little harder?
Q: How do I disable Jetty in my JBoss 3.x distribution?
A: Remove the jetty-plugin.sar from your server's deploy directory. Altenatively, if you only want to change the port number Jetty is responding to, open the jetty-plugin.sar file (it is in the zip format) and edit the jboss-service.xml file where you can find the MBean entries, including the HTTP socket listener's port number.