JavaServer Faces

Localizing Application Output

Remember the pages for setting user preferences from Chapter 9? One of the pages allows the user to select her preferred language; let’s add what’s needed for actually using the selected language. Figure 11-1 shows one of the preferences pages when Swedish is selected as the preferred language.

Figure 11-1. User information page with Swedish as the selected language

Java was designed with internationalization in mind and includes a number of classes to make the process as painless as possible. In i18n terminology, a locale represents a specific geographical region. In Java, a locale is represented by an instance of the java.util.Locale class. Java includes other classes for formatting dates and numbers according to the rules defined for a locale, and classes to help you include localized strings and other objects in an application.

You create a Locale instance using a constructor that takes a country code and language code as arguments:

java.util.Locale usLocale = new Locale("en", "US");

Here, a Locale for U.S. English is created. George Bernard Shaw (a famous Irish playwright) once observed, “England and America are two countries divided by a common language,” so it’s no surprise that both a language code and a country code are needed to describe some locales completely. The language code, a lowercase two-letter combination, is defined by the ISO 639 standard ...