org.springframework.web.servlet.i18n.CookieLocaleResolver Maven / Gradle / Ivy
/*
* Copyright 2002-2020 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
*
* https://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.lang.Nullable;
import org.springframework.util.Assert;
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.
*
* 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.
*
*
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 {@code Locale}.
*
Only used for overriding a cookie value if the locale has been
* changed in the course of the current request!
*
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 {@code TimeZone}.
*
Only used for overriding a cookie value if the locale has been
* changed in the course of the current request!
*
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 boolean languageTagCompliant = true;
private boolean rejectInvalidCookies = true;
@Nullable
private Locale defaultLocale;
@Nullable
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);
}
/**
* Specify whether this resolver's cookies should be compliant with BCP 47
* language tags instead of Java's legacy locale specification format.
*
The default is {@code true}, as of 5.1. Switch this to {@code false}
* for rendering Java's legacy locale specification format. For parsing,
* this resolver leniently accepts the legacy {@link Locale#toString}
* format as well as BCP 47 language tags in any case.
* @since 4.3
* @see #parseLocaleValue(String)
* @see #toLocaleValue(Locale)
* @see Locale#forLanguageTag(String)
* @see Locale#toLanguageTag()
*/
public void setLanguageTagCompliant(boolean languageTagCompliant) {
this.languageTagCompliant = languageTagCompliant;
}
/**
* Return whether this resolver's cookies should be compliant with BCP 47
* language tags instead of Java's legacy locale specification format.
* @since 4.3
*/
public boolean isLanguageTagCompliant() {
return this.languageTagCompliant;
}
/**
* Specify whether to reject cookies with invalid content (e.g. invalid format).
*
The default is {@code true}. Turn this off for lenient handling of parse
* failures, falling back to the default locale and time zone in such a case.
* @since 5.1.7
* @see #setDefaultLocale
* @see #setDefaultTimeZone
* @see #determineDefaultLocale
* @see #determineDefaultTimeZone
*/
public void setRejectInvalidCookies(boolean rejectInvalidCookies) {
this.rejectInvalidCookies = rejectInvalidCookies;
}
/**
* Return whether to reject cookies with invalid content (e.g. invalid format).
* @since 5.1.7
*/
public boolean isRejectInvalidCookies() {
return this.rejectInvalidCookies;
}
/**
* Set a fixed locale that this resolver will return if no cookie found.
*/
public void setDefaultLocale(@Nullable Locale defaultLocale) {
this.defaultLocale = defaultLocale;
}
/**
* Return the fixed locale that this resolver will return if no cookie found,
* if any.
*/
@Nullable
protected Locale getDefaultLocale() {
return this.defaultLocale;
}
/**
* Set a fixed time zone that this resolver will return if no cookie found.
* @since 4.0
*/
public void setDefaultTimeZone(@Nullable TimeZone defaultTimeZone) {
this.defaultTimeZone = defaultTimeZone;
}
/**
* Return the fixed time zone that this resolver will return if no cookie found,
* if any.
* @since 4.0
*/
@Nullable
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
@Nullable
public Locale getLocale() {
return (Locale) request.getAttribute(LOCALE_REQUEST_ATTRIBUTE_NAME);
}
@Override
@Nullable
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) {
Locale locale = null;
TimeZone timeZone = null;
// Retrieve and parse cookie value.
String cookieName = getCookieName();
if (cookieName != null) {
Cookie cookie = WebUtils.getCookie(request, cookieName);
if (cookie != null) {
String value = cookie.getValue();
String localePart = value;
String timeZonePart = null;
int separatorIndex = localePart.indexOf('/');
if (separatorIndex == -1) {
// Leniently accept older cookies separated by a space...
separatorIndex = localePart.indexOf(' ');
}
if (separatorIndex >= 0) {
localePart = value.substring(0, separatorIndex);
timeZonePart = value.substring(separatorIndex + 1);
}
try {
locale = (!"-".equals(localePart) ? parseLocaleValue(localePart) : null);
if (timeZonePart != null) {
timeZone = StringUtils.parseTimeZoneString(timeZonePart);
}
}
catch (IllegalArgumentException ex) {
if (isRejectInvalidCookies() &&
request.getAttribute(WebUtils.ERROR_EXCEPTION_ATTRIBUTE) == null) {
throw new IllegalStateException("Encountered invalid locale cookie '" +
cookieName + "': [" + value + "] due to: " + ex.getMessage());
}
else {
// Lenient handling (e.g. error dispatch): ignore locale/timezone parse exceptions
if (logger.isDebugEnabled()) {
logger.debug("Ignoring invalid locale cookie '" + cookieName +
"': [" + value + "] due to: " + ex.getMessage());
}
}
}
if (logger.isTraceEnabled()) {
logger.trace("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, @Nullable HttpServletResponse response, @Nullable Locale locale) {
setLocaleContext(request, response, (locale != null ? new SimpleLocaleContext(locale) : null));
}
@Override
public void setLocaleContext(HttpServletRequest request, @Nullable HttpServletResponse response,
@Nullable LocaleContext localeContext) {
Assert.notNull(response, "HttpServletResponse is required for CookieLocaleResolver");
Locale locale = null;
TimeZone timeZone = null;
if (localeContext != null) {
locale = localeContext.getLocale();
if (localeContext instanceof TimeZoneAwareLocaleContext) {
timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
}
addCookie(response,
(locale != null ? toLocaleValue(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)));
}
/**
* Parse the given locale value coming from an incoming cookie.
*
The default implementation calls {@link StringUtils#parseLocale(String)},
* accepting the {@link Locale#toString} format as well as BCP 47 language tags.
* @param localeValue the locale value to parse
* @return the corresponding {@code Locale} instance
* @since 4.3
* @see StringUtils#parseLocale(String)
*/
@Nullable
protected Locale parseLocaleValue(String localeValue) {
return StringUtils.parseLocale(localeValue);
}
/**
* Render the given locale as a text value for inclusion in a cookie.
*
The default implementation calls {@link Locale#toString()}
* or JDK 7's {@link Locale#toLanguageTag()}, depending on the
* {@link #setLanguageTagCompliant "languageTagCompliant"} configuration property.
* @param locale the locale to stringify
* @return a String representation for the given locale
* @since 4.3
* @see #isLanguageTagCompliant()
*/
protected String toLocaleValue(Locale locale) {
return (isLanguageTagCompliant() ? locale.toLanguageTag() : locale.toString());
}
/**
* Determine the default locale for the given request,
* Called if no locale cookie has been found.
*
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 time zone cookie has been found.
*
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
*/
@Nullable
protected TimeZone determineDefaultTimeZone(HttpServletRequest request) {
return getDefaultTimeZone();
}
}