About resource files
ü If there is no configuration, the default is the ApplicationResources.properties under the web-inf / classes directory.
ü If you work in Struts-Config.xml, you specify the default resource file as YYY.Properties under the web-inf / class / xxx directory.
ü If struts-config.xml made , specify the default resource file as YYY.Properties under the web-inf / class / xxx directory, However, specify the reference bundle "RES" so that the Struts Validator client verification can not find the relevant resources.
ü can configure multiple resource files
