“All the world’s a stage,” wrote William Shakespeare. But not all the players on that great and turbulent stage speak the great Bard’s native tongue. To be usable on a global scale, your software needs to communicate in many different languages. The menu labels, button strings, dialog messages, title bar/action bar titles, and error messages must be settable to the user’s choice of language. This is the topic of internationalization and localization. (Because the words “internationalization” and “localization” take a long time to say and write, they’re often abbreviated using their first and last letters and the count of omitted letters: I18N and L10N.)
If you’ve got your strings in a separate XML file, as we advised in Chapter 1, you have already done part of the work of internationalizing your app. Aren’t you glad you followed our advice?
Android provides a
Locale class to discover/control the internationalization settings. A default
Locale is inherited from the user’s language settings when your app starts up.
As a best practice, your app should never ask the users to choose a language, because they’ll already have chosen one when setting up the device.
Note that if you know internationalization from desktop Java, it’s pretty much the same here. We’ll explain as we go along, with examples, in this chapter.
Internationalization and localization consist of: