Locale-specific data must be tailored according to the conventions of
the end user's language and region. The text displayed by a user
interface is the most obvious example of locale-specific data. For
example, an application with a Cancel button in the U.S. will have an
Abbrechen button in Germany. In other countries this button will have
other labels. Obviously you don't want to hardcode this button label.
Wouldn't it be nice if you could automatically get the correct label
for a given
Locale? Fortunately you can, provided that you
isolate the locale-specific objects in a
ResourceBundle.
In this lesson you'll learn how to create and access
ResourceBundle objects. If you're in a hurry to examine
some coding examples, go ahead and check out the last two sections in
this lesson. Then you can come back to the first two sections to get
some conceptual information about ResourceBundle objects.
ResourceBundle objects contain locale-specific objects.
When you need a locale-specific object, you fetch it from a
ResourceBundle, which returns the object that matches the
end user's
Locale. This section explains how a
ResourceBundle is related to a
Locale, and
describes the
ResourceBundle subclasses.
Before you create your
ResourceBundle objects, you should
do a little planning. First, identify the locale-specific objects in
your program. Then organize them into categories and store them in
different
ResourceBundle objects accordingly.
If your application contains
String objects that need to
be translated into various languages, you can store these
String objects in a
PropertyResourceBundle,
which is backed up by a set of properties files. Since the properties
files are simple text files, they can be created and maintained by your
translators. You don't have to change the source code. In this section
you'll learn how to set up the properties files that back up a
PropertyResourceBundle.
The
ListResourceBundle class, which is a subclass of
ResourceBundle, manages locale-specific objects with a
list. A
ListResourceBundle is backed by a class file,
which means that you must code and compile a new source file each time
support for an additional
Locale is needed. However,
ListResourceBundle objects are useful because unlike
properties files, they can store any type of locale-specific object. By
stepping through a sample program, this section demonstrates how to use
a
ListResourceBundle.
This section represents new capabilities to improve the
ResourceBundle.getBundle factory flexibility.
The
ResourceBundle.Control class collaborates with the factory
methods for loading resource bundles. This allows to consider every substantial step
of the resource bundle-loading process and its cache control as a separate
method.
