In the last Windows versions of
install4j, we recently introduced some changes to improve how installers choose the default language and to mirror the new locale features in Java 7.
New language settings in Java 7
Until Java 7, a Java application retrieved the default locale from the
Formats tab in the
Region and Language Windows control panel, as shown below.
Even if this dialog box and other Windows dialogs are in English, a Java application running under Java 6 and previous versions will choose here
German and
Germany as default language and country, and this settings will end up in the
user.language and
user.country System properties, and thus in the default
Locale object. This might seem surprising at first, but language settings are often used to set the default Java formats for numbers and dates, so this actually makes sense.
Java 7 introduced new
Locale concepts that are initialized from the
Display Language setting shown below.
In Java 7, the information coming from these two different settings ends up in the following new system properties:
user.language.format
user.language.display
user.country.format
user.country.display
These properties are used to initialize the default locale
s - plural, because there are now 3 default locales! The old one returned by
Locale.getDefault(), and the two new ones returned by
Locale.getDefault(Locale.Category.DISPLAY) and
Locale.getDefault(Locale.Category.FORMAT). The two latter ones reflect the two Windows languages settings above and are used in different contexts. As you can guess,
Locale.getDefault(Locale.Category.FORMAT) will be used now in default Java formats.
But the first time you'll run your program under Java 7, you will see that its user interface will use the language chosen in the
Display Language Windows setting - a change from previous Java versions. Actually, the default language in Swing look and feel still depends on the locale returned by
Locale.getDefault(), but this locale is derived from
Locale.getDefault(Locale.Category.DISPLAY).
To help you understand these changes, let's run the following test application:
import java.text.DateFormat;
import java.util.*;
public class ShowLanguageAndLocale {
public static void main(String [] args) {
String [] messages = {
// language and country System properties
"user.language = " + System.getProperty("user.language"),
"user.country = " + System.getProperty("user.country"),
"user.language.display = " + System.getProperty("user.language.display"),
"user.country.display = " + System.getProperty("user.country.display"),
"user.language.format = " + System.getProperty("user.language.format"),
"user.country.format = " + System.getProperty("user.country.format"),
// default locales
"default locale = " + Locale.getDefault(),
"default display locale = " + Locale.getDefault(Locale.Category.DISPLAY),
"default format locale = " + Locale.getDefault(Locale.Category.FORMAT),
// date test
"Date: " + DateFormat.getDateInstance(DateFormat.FULL).format(new Date())};
javax.swing.JOptionPane.showMessageDialog(null, messages);
}
}
Under a Windows system configured in German for the
Formats settings and English for the
Display language settings, this application will show this dialog:
As expected, the title of the dialog box and the display language are in English, whereas the date and the format language are in German.
If you don't want this behavior in your application with Java 7 (for backward compatibility reasons for example), you can still force the old language settings based on the format language, by setting the new
sun.locale.formatasdefault property to
true.
When run with the following command:
java -Dsun.locale.formatasdefault=true ShowLanguageAndLocale
the previous application will display the following dialog box where the default locale is initialized from the
FORMAT locale (note that the value of the
DISPLAY locale is not lost):
Default language choice in install4j
install4j has a native part that also performs a language auto-detection that must be in sync with the default locale of the JVM. Since install4j 5.0.11, we handle this in the following manner: As many of you are still running their installers with Java 6 or a previous version, and don't want an unintentional change of behavior the day you'll support Java 7, we set the
sun.locale.formatasdefault System property to
true by default. If you run your application with Java 6, this won't change its behavior at all; if you run it under Java 7, this means that your application select the same locale as with Java 6.
As some of you might prefer the new choice made by Java 7, we also added the ability to pass the new
-Dsun.locale.formatasdefault=false parameter to installers and launchers. This parameter will make them initialize their language and country from the
Display Language setting whatever Java version they run with.
For more information about the Locale changes in Java 7, please read the new section about Locale scope in the Java tutorial.
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