DefaultLocaleSelectorProvider.java
/*
* Copyright 2018 Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.keycloak.locale;
import org.jboss.logging.Logger;
import org.keycloak.models.KeycloakSession;
import org.keycloak.models.RealmModel;
import org.keycloak.models.UserModel;
import org.keycloak.sessions.AuthenticationSessionModel;
import jakarta.ws.rs.core.Cookie;
import jakarta.ws.rs.core.HttpHeaders;
import java.util.List;
import java.util.Locale;
import java.util.stream.Collectors;
public class DefaultLocaleSelectorProvider implements LocaleSelectorProvider {
private static final Logger logger = Logger.getLogger(LocaleSelectorProvider.class);
private KeycloakSession session;
public DefaultLocaleSelectorProvider(KeycloakSession session) {
this.session = session;
}
@Override
public Locale resolveLocale(RealmModel realm, UserModel user) {
HttpHeaders requestHeaders = session.getContext().getRequestHeaders();
AuthenticationSessionModel session = this.session.getContext().getAuthenticationSession();
if (!realm.isInternationalizationEnabled()) {
return Locale.ENGLISH;
}
Locale userLocale = getUserLocale(realm, session, user, requestHeaders);
if (userLocale != null) {
return userLocale;
}
String realmDefaultLocale = realm.getDefaultLocale();
if (realmDefaultLocale != null) {
return Locale.forLanguageTag(realmDefaultLocale);
}
return Locale.ENGLISH;
}
private Locale getUserLocale(RealmModel realm, AuthenticationSessionModel session, UserModel user, HttpHeaders requestHeaders) {
Locale locale;
locale = getUserSelectedLocale(realm, session);
if (locale != null) {
return locale;
}
locale = getUserProfileSelection(realm, user);
if (locale != null) {
return locale;
}
locale = getClientSelectedLocale(realm, session);
if (locale != null) {
return locale;
}
locale = getLocaleCookieSelection(realm, requestHeaders);
if (locale != null) {
return locale;
}
locale = getAcceptLanguageHeaderLocale(realm, requestHeaders);
if (locale != null) {
return locale;
}
return null;
}
private Locale getUserSelectedLocale(RealmModel realm, AuthenticationSessionModel session) {
String locale = session == null ? this.session.getAttribute(USER_REQUEST_LOCALE, String.class) : session.getAuthNote(USER_REQUEST_LOCALE);
if (locale == null) {
return null;
}
return findLocale(realm, locale);
}
private Locale getUserProfileSelection(RealmModel realm, UserModel user) {
if (user == null) {
return null;
}
String locale = user.getFirstAttribute(UserModel.LOCALE);
if (locale == null) {
return null;
}
return findLocale(realm, locale);
}
private Locale getClientSelectedLocale(RealmModel realm, AuthenticationSessionModel session) {
if (session == null) {
return null;
}
String locale = session.getClientNote(LocaleSelectorProvider.CLIENT_REQUEST_LOCALE);
if (locale == null) {
return null;
}
return findLocale(realm, locale.split(" "));
}
private Locale getLocaleCookieSelection(RealmModel realm, HttpHeaders httpHeaders) {
if (httpHeaders == null) {
return null;
}
Cookie localeCookie = httpHeaders.getCookies().get(LOCALE_COOKIE);
if (localeCookie == null) {
return null;
}
return findLocale(realm, localeCookie.getValue());
}
private Locale getAcceptLanguageHeaderLocale(RealmModel realm, HttpHeaders httpHeaders) {
if (httpHeaders == null) {
return null;
}
List<Locale> acceptableLanguages = httpHeaders.getAcceptableLanguages();
if (acceptableLanguages == null || acceptableLanguages.isEmpty()) {
return null;
}
for (Locale l : acceptableLanguages) {
Locale locale = findLocale(realm, l.toLanguageTag());
if (locale != null) {
return locale;
}
}
return null;
}
private Locale findLocale(RealmModel realm, String... localeStrings) {
List<Locale> supportedLocales = realm.getSupportedLocalesStream()
.map(Locale::forLanguageTag).collect(Collectors.toList());
return findBestMatchingLocale(supportedLocales, localeStrings);
}
static Locale findBestMatchingLocale(List<Locale> supportedLocales, String... localeStrings) {
for (String localeString : localeStrings) {
if (localeString != null) {
Locale result = null;
Locale search = Locale.forLanguageTag(localeString);
for (Locale supportedLocale : supportedLocales) {
if (doesLocaleMatch(search, supportedLocale) && (result == null
|| doesFirstLocaleBetterMatchThanSecondLocale(supportedLocale, result, search))) {
result = supportedLocale;
}
}
if (result != null) {
return result;
}
}
}
return null;
}
private static boolean doesLocaleMatch(Locale candidate, Locale supportedLocale) {
return candidate.getLanguage().equals(supportedLocale.getLanguage())
&& ((candidate.getCountry().equals("") ^ supportedLocale.getCountry().equals(""))
|| candidate.getCountry().equals(supportedLocale.getCountry()));
}
private static boolean doesFirstLocaleBetterMatchThanSecondLocale(Locale firstLocale, Locale secondLocale,
Locale supportedLocale) {
if (firstLocale.getLanguage().equals(supportedLocale.getLanguage())
&& !secondLocale.getLanguage().equals(supportedLocale.getLanguage())) {
return true;
}
if (firstLocale.getCountry().equals(supportedLocale.getCountry())
&& !secondLocale.getCountry().equals(supportedLocale.getCountry())) {
return true;
}
return firstLocale.getVariant().equals(supportedLocale.getVariant())
&& !secondLocale.getVariant().equals(supportedLocale.getVariant());
}
@Override
public void close() {
}
}