Extract resource file name fron struts-config

I am using more than one message-resources in the struts-config. One is the Usual ApplicationResources and other if another properties file which I am refereing with a key bundle.resource. The file maaped to the bundle.resource changes with difference servers. I want to access the properies defined in this file in the Java code (not in JSP).

I can use the Property API provided by java. is there any way I can extract the name of the file associated with bundle.resource from struts-cinfig at runtime?