001/*
002 * Copyright 2002-2017 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.servlet;
018
019import java.util.Locale;
020
021import javax.servlet.http.HttpServletRequest;
022import javax.servlet.http.HttpServletResponse;
023
024import org.springframework.context.i18n.LocaleContext;
025import org.springframework.lang.Nullable;
026
027/**
028 * Extension of {@link LocaleResolver}, adding support for a rich locale context
029 * (potentially including locale and time zone information).
030 *
031 * @author Juergen Hoeller
032 * @since 4.0
033 * @see org.springframework.context.i18n.LocaleContext
034 * @see org.springframework.context.i18n.TimeZoneAwareLocaleContext
035 * @see org.springframework.context.i18n.LocaleContextHolder
036 * @see org.springframework.web.servlet.support.RequestContext#getTimeZone
037 * @see org.springframework.web.servlet.support.RequestContextUtils#getTimeZone
038 */
039public interface LocaleContextResolver extends LocaleResolver {
040
041        /**
042         * Resolve the current locale context via the given request.
043         * <p>This is primarily intended for framework-level processing; consider using
044         * {@link org.springframework.web.servlet.support.RequestContextUtils} or
045         * {@link org.springframework.web.servlet.support.RequestContext} for
046         * application-level access to the current locale and/or time zone.
047         * <p>The returned context may be a
048         * {@link org.springframework.context.i18n.TimeZoneAwareLocaleContext},
049         * containing a locale with associated time zone information.
050         * Simply apply an {@code instanceof} check and downcast accordingly.
051         * <p>Custom resolver implementations may also return extra settings in
052         * the returned context, which again can be accessed through downcasting.
053         * @param request the request to resolve the locale context for
054         * @return the current locale context (never {@code null}
055         * @see #resolveLocale(HttpServletRequest)
056         * @see org.springframework.web.servlet.support.RequestContextUtils#getLocale
057         * @see org.springframework.web.servlet.support.RequestContextUtils#getTimeZone
058         */
059        LocaleContext resolveLocaleContext(HttpServletRequest request);
060
061        /**
062         * Set the current locale context to the given one,
063         * potentially including a locale with associated time zone information.
064         * @param request the request to be used for locale modification
065         * @param response the response to be used for locale modification
066         * @param localeContext the new locale context, or {@code null} to clear the locale
067         * @throws UnsupportedOperationException if the LocaleResolver implementation
068         * does not support dynamic changing of the locale or time zone
069         * @see #setLocale(HttpServletRequest, HttpServletResponse, Locale)
070         * @see org.springframework.context.i18n.SimpleLocaleContext
071         * @see org.springframework.context.i18n.SimpleTimeZoneAwareLocaleContext
072         */
073        void setLocaleContext(HttpServletRequest request, @Nullable HttpServletResponse response,
074                        @Nullable LocaleContext localeContext);
075
076}