Although the Struts framework provides certain I18N capabilities that can be used with Tiles, Tiles also provides the ability to select a particular tile based on the user's locale. To support this feature in your application, you need to create a different Tiles definition file for each locale that you need to support. For example, if you need to support a set of definitions for the U.S. locale and a separate set for the German locale, you must create two separate definition files:
The suffix naming conventions follow the ones set by the java.util.ResourceBundle, which is also used by the resource bundles for Struts. When a request for a definition is made, the correct definition is determined by the included locale.
Once you have created the locale-specific definition files and placed them in the WEB-INF directory, the only other necessary step is to ensure that a Locale is stored in the user's HttpSession. The Tiles framework depends on the same Locale instance that Struts uses to determine which definition file to use. You will need to ensure that the Struts framework is storing the user's Locale in the session. This is accomplished by setting the locale attribute to true in the controller element. See "The Struts Configuration DTD" in Chapter 4 for more information on the controller element.
That's all there is to it. Note that you should still rely on the Struts resource bundle for locale-sensitive resources such as text, messages, and images. The I18N support in Tiles should be used for differences in layout based on the locale. Struts and Tiles work very well together to provide complete I18N support.