Delete the contents of ch04-recipe sub-directory inside the C: oo-cookbook directory.

Copy the ch04_web-app.roo script into the ch04-recipe directory.

Execute the ch04_web-app.roo script that creates the flight-app Roo project, sets up Hibernate as the persistence provider, configures MySQL as the database for the application, creates the Flight and FlightDescription JPA entities and defines a many-to-one relationship between the Flight and FlightDescription entities. If you are using a different database than MySQL or your connection settings are different than what is specified in the script, then modify the script accordingly.

Start the Roo shell from the C: oo-cookbookch04-recipe directory.

Execute the controller all command to create controllers and views corresponding to the JPA entities in the flight-app project, as shown here:

.. roo> controller all --package ~.web

Execute the perform eclipse command to update the project's classpath settings, as shown here:

.. roo> perform eclipse

Now, import the project into your Eclipse IDE.

For internationalizing the Roo-generated web user interface execute web mvc install language, as shown here:

.. roo> web mvc install language --code es

Created SRC_MAIN_WEBAPPWEB-INFi18nmessages_es.properties
Created SRC_MAIN_WEBAPPimageses.png
Managed SRC_MAIN_WEBAPPWEB-INFviewsfooter.jspx

The web mvc install language command accepts a single argument: code, which identifies the language code for which the support needs to be added to the web application. The code argument accepts a pre-defined language code, depending upon the languages supported by Spring Roo. Spring Roo contains translations for the standard messages and labels for the following language codes: de (German), en (English), es (Espanol), it (Italian), nl (Dutch), and sv (Swedish).

When the web mvc install language command is executed, Roo processes the command by taking the following actions:

To check if the support for the Espanol language is correctly installed, deploy and run the flight-app application. The following screenshot shows the home page of the flight-app application, after the Espanol language support is added:

As the given screenshot shows, an additional image icon is displayed to allow users to change the language of the web application to Espanol. When a user clicks the image icon corresponding to a language, the lang request parameter is set in the request, which is used by LocaleChangeInterceptor (configured in the /WEB-INF/spring/webmvc-config.xml) for changing the current locale.

The CookieLocaleResolver configured in the /WEB-INF/spring/webmvc-config.xml stores a cookie named locale in the browser, so that users don't need to change their preferred language every time they access the web application.

In the Auto-generating Spring MVC controllers and the JSPX views from the JPA entities recipe, we discussed that the messages.properties contains messages and labels that are common to all Roo-generated web applications and the application.properties contains application-specific messages and labels.

As Roo can't provide translations for application-specific messages and labels, the web mvc install language command doesn't create an application_<language-code>.properties file. It is left up to the developer to create an application_<language-code>.properties file for specific language codes and provide translations.