Set environment variable in shell script/access in Tomcat Application
According to the docs (http://tomcat.apache.org/tomcat-7.0-doc/RUNNING.txt) you should set all env vars in $CATALINA_HOME/bin/setenv.sh
EDIT: For completeness, I guess it's worth mentioning that even though this is the recommended way, the docs above state that:
By default the setenv script file is absent. If the script file is present both in CATALINA_BASE and in CATALINA_HOME, the one in CATALINA_BASE is preferred.
In case it is absent, you might also want to look for env vars in:
/etc/tomcat/tomcat[67].conf
(suse) or/etc/default/tomcat[67].conf
(e.g. ubuntu) or/etc/sysconfig/tomcat[67].conf
(rhel, fedora)