Charles So wrote:
  Hello,
 After fixing the xwiki.log permission error, I have another error upon
 loading xwiki in Tomcat.
 The error is:
 java.lang.InternalError: Can't connect to window server - not enough
 permissions. 
This means that you should either find a way to give the Java process
access to the graphical server, or start it with a headless option.
Maybe this helps: 
http://wiki.apache.org/tomcat/FAQ/Linux_Unix#Q2
--
Sergiu Dumitriu
http://purl.org/net/sergiu/