I config a apache http server to rewrite the incoming request and redirect it to local file, this apache serve running because the front-finish of the jboss server and fasten using the ajp13, the mode_jk config will transmit *.htm towards the jboss worker.
below is negligence apache httpd.conf configuration:

Listen 80
NameVirtualHost *:80

<Directory />
  Order allow,deny
  Allow from all
<Directory>

SetEnvIf Request_URI "/tmp/default.htm" no-jk

<VirtualHost *:80>
   ServerName www.example.com
   DocumentRoot /home/admin/mf/
   RewriteEngine on
   RewriteRule ^/index.htm /tmp/default.htm
</VirtualHost>

The configuration does't work unless of course I added the SetEnvIf directive. I analyse the server process the request work as below: user fire a http request:

http://www.example.com/index.htm

apache discover the virtual host based on the Host in http header, then perform the rewrite, following the substitution the incoming URL be a absoult URI:

/home/admin/mf/tmp/default.htm

but this URI isn't forwarded to local system, it will likely be forwarded to back-ending jboss unless of course I add the SetEnvIf config, this just the analyse of myself, anybody can produce a explicit explanation from the process from do rewrite to transfer the request to jboss, exactly what the URL is transfered to jboss, the URL after rewrited:

/home/admin/mf/tmp/default.htm 

transfered to jboss isn't seem sensible as my analysise. Thanks