org.springframework.web.servlet.LocaleResolver 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.lang.Nullable;
/**
* Interface for web-based locale resolution strategies that allows for
* both locale resolution via the request and locale modification via
* request and response.
*
* This interface allows for implementations based on request, session,
* cookies, etc. The default implementation is
* {@link org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver},
* simply using the request's locale provided by the respective HTTP header.
*
*
Use {@link org.springframework.web.servlet.support.RequestContext#getLocale()}
* to retrieve the current locale in controllers or views, independent
* of the actual resolution strategy.
*
*
Note: As of Spring 4.0, there is an extended strategy interface
* called {@link LocaleContextResolver}, allowing for resolution of
* a {@link org.springframework.context.i18n.LocaleContext} object,
* potentially including associated time zone information. Spring's
* provided resolver implementations implement the extended
* {@link LocaleContextResolver} interface wherever appropriate.
*
* @author Juergen Hoeller
* @since 27.02.2003
* @see LocaleContextResolver
* @see org.springframework.context.i18n.LocaleContextHolder
* @see org.springframework.web.servlet.support.RequestContext#getLocale
* @see org.springframework.web.servlet.support.RequestContextUtils#getLocale
*/
public interface LocaleResolver {
/**
* Resolve the current locale via the given request.
*
Can return a default locale as fallback in any case.
* @param request the request to resolve the locale for
* @return the current locale (never {@code null})
*/
Locale resolveLocale(HttpServletRequest request);
/**
* Set the current locale to the given one.
* @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
*/
void setLocale(HttpServletRequest request, @Nullable HttpServletResponse response, @Nullable Locale locale);
}