<portlet> ... <localized-resource-bundle>com.example.resources.messages</localized-resource-bundle> ... </portlet> public void serveResource(ResourceRequest request, ResourceResponse response) { Locale locale = request.getLocale(); ResourceBundle resourceBundle = ResourceBundle.getBundle("com.example.resources.messages", locale); String welcomeMessage = resourceBundle.getString("welcome_message"); response.getWriter().write(welcomeMessage); }