Hi
I am doing somewhat similar to this in my application. Hope this will help you.
I have a
jsp where i am giving the option to select the language and country for the user. When i submit the page, i will get the values in my action class and using those values i am setting the locale in session as follows
session.setAttribute(Globals.LOCALE_KEY,new Locale("es","ES"));
Here i have selected spanish as my language and country. Using that i am creating a locale as es_ES . Corrsponding to that i should have the property file to be loaded as fileName_es_ES.properties.
So when this locale reference comes it will check whether corresponding file is available or not and will load.
Refer ResourceBundle class of java.and also MessageResources class of Struts . These classes will help you and also refer internationalization part in struts.