/**
* This code is currently common to all {@link ViewHandlingStrategy} instances.
*
* @see ViewHandler#calculateLocale(javax.faces.context.FacesContext)
*/
public Locale calculateLocale(FacesContext context) {
Util.notNull("context", context);
Locale result = null;
// determine the locales that are acceptable to the client based on the
// Accept-Language header and the find the best match among the
// supported locales specified by the client.
Iterator<Locale> locales = context.getExternalContext().getRequestLocales();
while (locales.hasNext()) {
Locale perf = locales.next();
result = findMatch(context, perf);
if (result != null) {
break;
}
}
// no match is found.
if (result == null) {
if (context.getApplication().getDefaultLocale() == null) {
result = Locale.getDefault();
} else {
result = context.getApplication().getDefaultLocale();
}
}
return result;
}
/**
* Attempts to find a matching locale based on <code>pref</code> and list of supported locales,
* using the matching algorithm as described in JSTL 8.3.2.
*
* @param context the <code>FacesContext</code> for the current request
* @param pref the preferred locale
* @return the Locale based on pref and the matching alogritm specified in JSTL 8.3.2
*/
protected Locale findMatch(FacesContext context, Locale pref) {
Locale result = null;
Iterator<Locale> it = context.getApplication().getSupportedLocales();
while (it.hasNext()) {
Locale supportedLocale = it.next();
if (pref.equals(supportedLocale)) {
// exact match
result = supportedLocale;
break;
} else {
// Make sure the preferred locale doesn't have country
// set, when doing a language match, For ex., if the
// preferred locale is "en-US", if one of supported
// locales is "en-UK", even though its language matches
// that of the preferred locale, we must ignore it.
if (pref.getLanguage().equals(supportedLocale.getLanguage())
&& supportedLocale.getCountry().length() == 0) {
result = supportedLocale;
}
}
}
// if it's not in the supported locales,
if (null == result) {
Locale defaultLocale = context.getApplication().getDefaultLocale();
if (defaultLocale != null) {
if (pref.equals(defaultLocale)) {
// exact match
result = defaultLocale;
} else {
// Make sure the preferred locale doesn't have country
// set, when doing a language match, For ex., if the
// preferred locale is "en-US", if one of supported
// locales is "en-UK", even though its language matches
// that of the preferred locale, we must ignore it.
if (pref.getLanguage().equals(defaultLocale.getLanguage())
&& defaultLocale.getCountry().length() == 0) {
result = defaultLocale;
}
}
}
}
return result;
}