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/* * Copyright 2002-2017 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.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.context.i18n.LocaleContext; import org.springframework.context.i18n.TimeZoneAwareLocaleContext; import org.springframework.lang.Nullable; 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 specified default locale or the request's * accept-header locale. * * <p>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. * * <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}. * * <p>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. * * <p>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 * @since 27.02.2003 * @see #setDefaultLocale * @see #setDefaultTimeZone */ public class SessionLocaleResolver extends AbstractLocaleContextResolver { /** * Name of the session attribute that holds the Locale. * Only used internally by this implementation. * <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_SESSION_ATTRIBUTE_NAME = SessionLocaleResolver.class.getName() + ".LOCALE"; /** * Name of the session attribute that holds the TimeZone. * Only used internally by this implementation. * <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_SESSION_ATTRIBUTE_NAME = SessionLocaleResolver.class.getName() + ".TIME_ZONE"; private String localeAttributeName = LOCALE_SESSION_ATTRIBUTE_NAME; private String timeZoneAttributeName = TIME_ZONE_SESSION_ATTRIBUTE_NAME; /** * Specify the name of the corresponding attribute in the {@code HttpSession}, * holding the current {@link Locale} value. * <p>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. * <p>The default is an internal {@link #TIME_ZONE_SESSION_ATTRIBUTE_NAME}. * @since 4.3.8 */ public void setTimeZoneAttributeName(String timeZoneAttributeName) { this.timeZoneAttributeName = timeZoneAttributeName; } @Override public Locale resolveLocale(HttpServletRequest request) { Locale locale = (Locale) WebUtils.getSessionAttribute(request, this.localeAttributeName); if (locale == null) { locale = determineDefaultLocale(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 = determineDefaultLocale(request); } return locale; } @Override @Nullable public TimeZone getTimeZone() { TimeZone timeZone = (TimeZone) WebUtils.getSessionAttribute(request, timeZoneAttributeName); if (timeZone == null) { timeZone = determineDefaultTimeZone(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) { timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone(); } } WebUtils.setSessionAttribute(request, this.localeAttributeName, locale); WebUtils.setSessionAttribute(request, this.timeZoneAttributeName, timeZone); } /** * Determine the default locale for the given request, * Called if no Locale session attribute 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 session attribute 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 */ @Nullable protected TimeZone determineDefaultTimeZone(HttpServletRequest request) { return getDefaultTimeZone(); } }