org.springframework.web.servlet.LocaleContextResolver 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;
import java.util.Locale;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.context.i18n.LocaleContext;
import org.springframework.context.i18n.SimpleLocaleContext;
import org.springframework.lang.Nullable;
/**
* Extension of {@link LocaleResolver} that adds support for a rich locale context
* (potentially including locale and time zone information).
*
* Also provides {@code default} implementations of {@link #resolveLocale} and
* {@link #setLocale} which delegate to {@link #resolveLocaleContext} and
* {@link #setLocaleContext}, respectively.
*
* @author Juergen Hoeller
* @author Sam Brannen
* @since 4.0
* @see org.springframework.context.i18n.LocaleContext
* @see org.springframework.context.i18n.TimeZoneAwareLocaleContext
* @see org.springframework.context.i18n.LocaleContextHolder
* @see org.springframework.web.servlet.support.RequestContext#getTimeZone
* @see org.springframework.web.servlet.support.RequestContextUtils#getTimeZone
*/
public interface LocaleContextResolver extends LocaleResolver {
/**
* Resolve the current locale context via the given request.
*
This is primarily intended for framework-level processing; consider using
* {@link org.springframework.web.servlet.support.RequestContextUtils} or
* {@link org.springframework.web.servlet.support.RequestContext} for
* application-level access to the current locale and/or time zone.
*
The returned context may be a
* {@link org.springframework.context.i18n.TimeZoneAwareLocaleContext},
* containing a locale with associated time zone information.
* Simply apply an {@code instanceof} check and downcast accordingly.
*
Custom resolver implementations may also return extra settings in
* the returned context, which again can be accessed through downcasting.
* @param request the request to resolve the locale context for
* @return the current locale context (never {@code null}
* @see #resolveLocale(HttpServletRequest)
* @see org.springframework.web.servlet.support.RequestContextUtils#getLocale
* @see org.springframework.web.servlet.support.RequestContextUtils#getTimeZone
*/
LocaleContext resolveLocaleContext(HttpServletRequest request);
/**
* Set the current locale context to the given one,
* potentially including a locale with associated time zone information.
* @param request the request to be used for locale modification
* @param response the response to be used for locale modification
* @param localeContext the new locale context, or {@code null} to clear the locale
* @throws UnsupportedOperationException if the LocaleResolver implementation
* does not support dynamic changing of the locale or time zone
* @see #setLocale(HttpServletRequest, HttpServletResponse, Locale)
* @see org.springframework.context.i18n.SimpleLocaleContext
* @see org.springframework.context.i18n.SimpleTimeZoneAwareLocaleContext
*/
void setLocaleContext(HttpServletRequest request, @Nullable HttpServletResponse response,
@Nullable LocaleContext localeContext);
/**
* Default implementation of {@link LocaleResolver#resolveLocale(HttpServletRequest)}
* that delegates to {@link #resolveLocaleContext(HttpServletRequest)}, falling
* back to {@link HttpServletRequest#getLocale()} if necessary.
* @param request the request to resolve the locale for
* @return the current locale (never {@code null})
* @since 6.0
*/
@Override
default Locale resolveLocale(HttpServletRequest request) {
Locale locale = resolveLocaleContext(request).getLocale();
return (locale != null ? locale : request.getLocale());
}
/**
* Default implementation of {@link LocaleResolver#setLocale(HttpServletRequest,
* HttpServletResponse, Locale)} that delegates to
* {@link #setLocaleContext(HttpServletRequest, HttpServletResponse, LocaleContext)},
* using a {@link SimpleLocaleContext}.
* @param request the request to be used for locale modification
* @param response the response to be used for locale modification
* @param locale the new locale, or {@code null} to clear the locale
* @throws UnsupportedOperationException if the LocaleResolver implementation
* does not support dynamic changing of the locale
* @since 6.0
*/
@Override
default void setLocale(HttpServletRequest request, @Nullable HttpServletResponse response, @Nullable Locale locale) {
setLocaleContext(request, response, (locale != null ? new SimpleLocaleContext(locale) : null));
}
}