org.springframework.web.servlet.i18n.SessionLocaleResolver Maven / Gradle / Ivy
/*
* Copyright 2002-2022 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 java.util.function.Function;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.context.i18n.LocaleContext;
import org.springframework.context.i18n.TimeZoneAwareLocaleContext;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.web.util.WebUtils;
/**
* {@link org.springframework.web.servlet.LocaleResolver} implementation that
* uses a locale attribute in the user's session in case of a custom setting,
* with a fallback to the configured default locale, the request's
* {@code Accept-Language} header, or the default locale for the server.
*
* This is most appropriate if the application needs user sessions anyway,
* i.e. when the {@code HttpSession} does not have to be created just for storing
* the user's locale. The session may optionally contain an associated time zone
* attribute 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}.
*
*
In contrast to {@link CookieLocaleResolver}, this strategy stores locally
* chosen locale settings in the Servlet container's {@code HttpSession}. As a
* consequence, those settings are just temporary for each session and therefore
* lost when each session terminates.
*
*
Note that there is no direct relationship with external session management
* mechanisms such as the "Spring Session" project. This {@code LocaleResolver}
* will simply evaluate and modify corresponding {@code HttpSession} attributes
* against the current {@code HttpServletRequest}.
*
* @author Juergen Hoeller
* @author Vedran Pavic
* @since 27.02.2003
* @see #setDefaultLocale
* @see #setDefaultTimeZone
*/
public class SessionLocaleResolver extends AbstractLocaleContextResolver {
/**
* Default name of the session attribute that holds the Locale.
*
Only used internally by this implementation.
*
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_SESSION_ATTRIBUTE_NAME = SessionLocaleResolver.class.getName() + ".LOCALE";
/**
* Default name of the session attribute that holds the TimeZone.
*
Only used internally by this implementation.
*
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_SESSION_ATTRIBUTE_NAME = SessionLocaleResolver.class.getName() + ".TIME_ZONE";
private String localeAttributeName = LOCALE_SESSION_ATTRIBUTE_NAME;
private String timeZoneAttributeName = TIME_ZONE_SESSION_ATTRIBUTE_NAME;
private Function defaultLocaleFunction = request -> {
Locale defaultLocale = getDefaultLocale();
return (defaultLocale != null ? defaultLocale : request.getLocale());
};
private Function defaultTimeZoneFunction = request -> getDefaultTimeZone();
/**
* Specify the name of the corresponding attribute in the {@code HttpSession},
* holding the current {@link Locale} value.
* The default is an internal {@link #LOCALE_SESSION_ATTRIBUTE_NAME}.
* @since 4.3.8
*/
public void setLocaleAttributeName(String localeAttributeName) {
this.localeAttributeName = localeAttributeName;
}
/**
* Specify the name of the corresponding attribute in the {@code HttpSession},
* holding the current {@link TimeZone} value.
*
The default is an internal {@link #TIME_ZONE_SESSION_ATTRIBUTE_NAME}.
* @since 4.3.8
*/
public void setTimeZoneAttributeName(String timeZoneAttributeName) {
this.timeZoneAttributeName = timeZoneAttributeName;
}
/**
* Set the function used to determine the default locale for the given request,
* called if no {@link Locale} session attribute has been found.
*
The default implementation returns the configured
* {@linkplain #setDefaultLocale(Locale) default locale}, if any, and otherwise
* falls back to the request's {@code Accept-Language} header locale or the
* default locale for the server.
* @param defaultLocaleFunction the function used to determine the default locale
* @since 6.0
* @see #setDefaultLocale
* @see jakarta.servlet.http.HttpServletRequest#getLocale()
*/
public void setDefaultLocaleFunction(Function defaultLocaleFunction) {
Assert.notNull(defaultLocaleFunction, "defaultLocaleFunction must not be null");
this.defaultLocaleFunction = defaultLocaleFunction;
}
/**
* Set the function used to determine the default time zone for the given request,
* called if no {@link TimeZone} session attribute has been found.
* The default implementation returns the configured default time zone,
* if any, or {@code null} otherwise.
* @param defaultTimeZoneFunction the function used to determine the default time zone
* @since 6.0
* @see #setDefaultTimeZone
*/
public void setDefaultTimeZoneFunction(Function defaultTimeZoneFunction) {
Assert.notNull(defaultTimeZoneFunction, "defaultTimeZoneFunction must not be null");
this.defaultTimeZoneFunction = defaultTimeZoneFunction;
}
@Override
public Locale resolveLocale(HttpServletRequest request) {
Locale locale = (Locale) WebUtils.getSessionAttribute(request, this.localeAttributeName);
if (locale == null) {
locale = this.defaultLocaleFunction.apply(request);
}
return locale;
}
@Override
public LocaleContext resolveLocaleContext(final HttpServletRequest request) {
return new TimeZoneAwareLocaleContext() {
@Override
public Locale getLocale() {
Locale locale = (Locale) WebUtils.getSessionAttribute(request, localeAttributeName);
if (locale == null) {
locale = defaultLocaleFunction.apply(request);
}
return locale;
}
@Override
@Nullable
public TimeZone getTimeZone() {
TimeZone timeZone = (TimeZone) WebUtils.getSessionAttribute(request, timeZoneAttributeName);
if (timeZone == null) {
timeZone = defaultTimeZoneFunction.apply(request);
}
return timeZone;
}
};
}
@Override
public void setLocaleContext(HttpServletRequest request, @Nullable HttpServletResponse response,
@Nullable LocaleContext localeContext) {
Locale locale = null;
TimeZone timeZone = null;
if (localeContext != null) {
locale = localeContext.getLocale();
if (localeContext instanceof TimeZoneAwareLocaleContext timeZoneAwareLocaleContext) {
timeZone = timeZoneAwareLocaleContext.getTimeZone();
}
}
WebUtils.setSessionAttribute(request, this.localeAttributeName, locale);
WebUtils.setSessionAttribute(request, this.timeZoneAttributeName, timeZone);
}
/**
* Determine the default locale for the given request, called if no
* {@link Locale} session attribute has been found.
* The default implementation returns the configured
* {@linkplain #setDefaultLocale(Locale) default locale}, if any, and otherwise
* falls back to the request's {@code Accept-Language} header locale or the
* default locale for the server.
* @param request the request to resolve the locale for
* @return the default locale (never {@code null})
* @see #setDefaultLocale
* @see jakarta.servlet.http.HttpServletRequest#getLocale()
* @deprecated as of 6.0, in favor of {@link #setDefaultLocaleFunction(Function)}
*/
@Deprecated(since = "6.0")
protected Locale determineDefaultLocale(HttpServletRequest request) {
return this.defaultLocaleFunction.apply(request);
}
/**
* Determine the default time zone for the given request, called if no
* {@link TimeZone} session attribute has been found.
*
The default implementation returns the configured 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
* @deprecated as of 6.0, in favor of {@link #setDefaultTimeZoneFunction(Function)}
*/
@Deprecated(since = "6.0")
@Nullable
protected TimeZone determineDefaultTimeZone(HttpServletRequest request) {
return this.defaultTimeZoneFunction.apply(request);
}
}