If you want to enable Tomcat for an addon domain then follow the steps :

root@server[#] cd /usr/local/jakarta/tomcat/conf/
root@server[#] vi  server.xml

Add these lines to the server.xml  file :
=============================================================
<Host name=”domain.com” appBase=”/home/username/public_html/domain.com”>
<Alias>www.domain.com</Alias>
<Context path=”" reloadable=”true” docBase=”/home/username/public_html/domain.com” debug=”1″/>
<Context path=”/manager” debug=”0″ privileged=”true”
docBase=”/usr/local/jakarta/tomcat/server/webapps/manager”>
</Context>
</Host>

:wq!

=============================================================
Then restart the tomcat service.

Note  : here  “appBase”  and “docBase” is the path to addon domain.

That’ s all this will do it.