If you remember, there is a drop-down list with country names on the Registration page. How could we display the names of the countries in German? Nothing can be easier. Currently, the English labels for this drop-down list are defined in the root message catalog like this:

Country.GERMANY=Germany
country.uk=United Kingdom
COUNTRY.USA=United States

We can create a separate message catalog for the Registration page if we wish so and move these entries there, or leave everything as it is in case the same messages might be needed for some other page. To provide the countries labels in German, all we need is to create an appropriate German message catalog, with German values for the labels.

Let's create a new file, app_de.properties in WEB-INF directory. We could translate all the contents of the app.properties file, put the translations into the new message catalog and then internationalize all the labels of the Registration page. However, you already know...