/*
* Copyright 2002-2013 the original author or authors.
*
* 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.springframework.web.servlet.i18n;
import java.util.Locale;
import java.util.TimeZone;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.context.i18n.LocaleContext;
import org.springframework.context.i18n.SimpleLocaleContext;
import org.springframework.context.i18n.TimeZoneAwareLocaleContext;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.LocaleContextResolver;
import org.springframework.web.servlet.LocaleResolver;
import org.springframework.web.util.CookieGenerator;
import org.springframework.web.util.WebUtils;
/**
* {@link LocaleResolver} implementation that uses a cookie sent back to the user
* in case of a custom setting, with a fallback to the specified default locale
* or the request's accept-header locale.
*
* <p>This is particularly useful for stateless applications without user sessions.
* The cookie may optionally contain an associated time zone value as well;
* alternatively, you may specify a default time zone.
*
* <p>Custom controllers can override the user's locale and time zone by calling
* {@code #setLocale(Context)} on the resolver, e.g. responding to a locale change
* request. As a more convenient alternative, consider using
* {@link org.springframework.web.servlet.support.RequestContext#changeLocale}.
*
* @author Juergen Hoeller
* @author Jean-Pierre Pawlak
* @since 27.02.2003
* @see #setDefaultLocale
* @see #setDefaultTimeZone
*/
public class CookieLocaleResolver extends CookieGenerator implements LocaleContextResolver {
/**
* The name of the request attribute that holds the Locale.
* <p>Only used for overriding a cookie value if the locale has been
* changed in the course of the current request!
* <p>Use {@code RequestContext(Utils).getLocale()}
* to retrieve the current locale in controllers or views.
* @see org.springframework.web.servlet.support.RequestContext#getLocale
* @see org.springframework.web.servlet.support.RequestContextUtils#getLocale
*/
public static final String LOCALE_REQUEST_ATTRIBUTE_NAME = CookieLocaleResolver.class.getName() + ".LOCALE";
/**
* The name of the request attribute that holds the TimeZone.
* <p>Only used for overriding a cookie value if the locale has been
* changed in the course of the current request!
* <p>Use {@code RequestContext(Utils).getTimeZone()}
* to retrieve the current time zone in controllers or views.
* @see org.springframework.web.servlet.support.RequestContext#getTimeZone
* @see org.springframework.web.servlet.support.RequestContextUtils#getTimeZone
*/
public static final String TIME_ZONE_REQUEST_ATTRIBUTE_NAME = CookieLocaleResolver.class.getName() + ".TIME_ZONE";
/**
* The default cookie name used if none is explicitly set.
*/
public static final String DEFAULT_COOKIE_NAME = CookieLocaleResolver.class.getName() + ".LOCALE";
private Locale defaultLocale;
private TimeZone defaultTimeZone;
/**
* Create a new instance of the {@link CookieLocaleResolver} class
* using the {@link #DEFAULT_COOKIE_NAME default cookie name}.
*/
public CookieLocaleResolver() {
setCookieName(DEFAULT_COOKIE_NAME);
}
/**
* Set a fixed Locale that this resolver will return if no cookie found.
*/
public void setDefaultLocale(Locale defaultLocale) {
this.defaultLocale = defaultLocale;
}
/**
* Return the fixed Locale that this resolver will return if no cookie found,
* if any.
*/
protected Locale getDefaultLocale() {
return this.defaultLocale;
}
/**
* Set a fixed TimeZone that this resolver will return if no cookie found.
*/
public void setDefaultTimeZone(TimeZone defaultTimeZone) {
this.defaultTimeZone = defaultTimeZone;
}
/**
* Return the fixed TimeZone that this resolver will return if no cookie found,
* if any.
*/
protected TimeZone getDefaultTimeZone() {
return this.defaultTimeZone;
}
@Override
public Locale resolveLocale(HttpServletRequest request) {
parseLocaleCookieIfNecessary(request);
return (Locale) request.getAttribute(LOCALE_REQUEST_ATTRIBUTE_NAME);
}
@Override
public LocaleContext resolveLocaleContext(final HttpServletRequest request) {
parseLocaleCookieIfNecessary(request);
return new TimeZoneAwareLocaleContext() {
@Override
public Locale getLocale() {
return (Locale) request.getAttribute(LOCALE_REQUEST_ATTRIBUTE_NAME);
}
@Override
public TimeZone getTimeZone() {
return (TimeZone) request.getAttribute(TIME_ZONE_REQUEST_ATTRIBUTE_NAME);
}
};
}
private void parseLocaleCookieIfNecessary(HttpServletRequest request) {
if (request.getAttribute(LOCALE_REQUEST_ATTRIBUTE_NAME) == null) {
// Retrieve and parse cookie value.
Cookie cookie = WebUtils.getCookie(request, getCookieName());
Locale locale = null;
TimeZone timeZone = null;
if (cookie != null) {
String value = cookie.getValue();
String localePart = value;
String timeZonePart = null;
int spaceIndex = localePart.indexOf(' ');
if (spaceIndex != -1) {
localePart = value.substring(0, spaceIndex);
timeZonePart = value.substring(spaceIndex + 1);
}
locale = (!"-".equals(localePart) ? StringUtils.parseLocaleString(localePart) : null);
if (timeZonePart != null) {
timeZone = StringUtils.parseTimeZoneString(timeZonePart);
}
if (logger.isDebugEnabled()) {
logger.debug("Parsed cookie value [" + cookie.getValue() + "] into locale '" + locale +
"'" + (timeZone != null ? " and time zone '" + timeZone.getID() + "'" : ""));
}
}
request.setAttribute(LOCALE_REQUEST_ATTRIBUTE_NAME,
(locale != null ? locale: determineDefaultLocale(request)));
request.setAttribute(TIME_ZONE_REQUEST_ATTRIBUTE_NAME,
(timeZone != null ? timeZone : determineDefaultTimeZone(request)));
}
}
@Override
public void setLocale(HttpServletRequest request, HttpServletResponse response, Locale locale) {
setLocaleContext(request, response, (locale != null ? new SimpleLocaleContext(locale) : null));
}
@Override
public void setLocaleContext(HttpServletRequest request, HttpServletResponse response, LocaleContext localeContext) {
Locale locale = null;
TimeZone timeZone = null;
if (localeContext != null) {
locale = localeContext.getLocale();
if (localeContext instanceof TimeZoneAwareLocaleContext) {
timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
}
addCookie(response, (locale != null ? locale : "-") + (timeZone != null ? ' ' + timeZone.getID() : ""));
}
else {
removeCookie(response);
}
request.setAttribute(LOCALE_REQUEST_ATTRIBUTE_NAME,
(locale != null ? locale: determineDefaultLocale(request)));
request.setAttribute(TIME_ZONE_REQUEST_ATTRIBUTE_NAME,
(timeZone != null ? timeZone : determineDefaultTimeZone(request)));
}
/**
* Determine the default locale for the given request,
* Called if no locale cookie has been found.
* <p>The default implementation returns the specified default locale,
* if any, else falls back to the request's accept-header locale.
* @param request the request to resolve the locale for
* @return the default locale (never {@code null})
* @see #setDefaultLocale
* @see javax.servlet.http.HttpServletRequest#getLocale()
*/
protected Locale determineDefaultLocale(HttpServletRequest request) {
Locale defaultLocale = getDefaultLocale();
if (defaultLocale == null) {
defaultLocale = request.getLocale();
}
return defaultLocale;
}
/**
* Determine the default time zone for the given request,
* Called if no TimeZone cookie has been found.
* <p>The default implementation returns the specified default time zone,
* if any, or {@code null} otherwise.
* @param request the request to resolve the time zone for
* @return the default time zone (or {@code null} if none defined)
* @see #setDefaultTimeZone
*/
protected TimeZone determineDefaultTimeZone(HttpServletRequest request) {
return getDefaultTimeZone();
}
}