I would put the JAVA application up with either mod_proxy, or mod_proxy_ajp. The later in case a.) this is a tomcat (compatible application server) and b.) you have access to the configuration of the application server.
You have to take care that your server (Apache) doesn't relay proxy requests. Most distributions have this savely set by default, but double check it. The Apache docu is your friend: http://httpd.apache.org/docs/2.2/mod/mod_proxy.html
Port 8080 is a different matter as this is served by your application server itself. If you want to have it handled by the Apache as well, you should deactivate Catalina (Tomcat webserver) and set it up to serve via AJP.