/*
* Copyright 2002-2012 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
*
* http://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.support;
import java.util.Locale;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import org.springframework.ui.context.Theme;
import org.springframework.ui.context.ThemeSource;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import org.springframework.web.servlet.DispatcherServlet;
import org.springframework.web.servlet.FlashMap;
import org.springframework.web.servlet.FlashMapManager;
import org.springframework.web.servlet.LocaleResolver;
import org.springframework.web.servlet.ThemeResolver;
/**
* Utility class for easy access to request-specific state which has been
* set by the {@link org.springframework.web.servlet.DispatcherServlet}.
*
* <p>Supports lookup of current WebApplicationContext, LocaleResolver,
* Locale, ThemeResolver, Theme, and MultipartResolver.
*
* @author Juergen Hoeller
* @since 03.03.2003
* @see RequestContext
* @see org.springframework.web.servlet.DispatcherServlet
*/
public abstract class RequestContextUtils {
/**
* Look for the WebApplicationContext associated with the DispatcherServlet
* that has initiated request processing.
* @param request current HTTP request
* @return the request-specific web application context
* @throws IllegalStateException if no servlet-specific context has been found
*/
public static WebApplicationContext getWebApplicationContext(ServletRequest request)
throws IllegalStateException {
return getWebApplicationContext(request, null);
}
/**
* Look for the WebApplicationContext associated with the DispatcherServlet
* that has initiated request processing, and for the global context if none
* was found associated with the current request. This method is useful to
* allow components outside the framework, such as JSP tag handlers,
* to access the most specific application context available.
* @param request current HTTP request
* @param servletContext current servlet context
* @return the request-specific WebApplicationContext, or the global one
* if no request-specific context has been found
* @throws IllegalStateException if neither a servlet-specific nor a
* global context has been found
*/
public static WebApplicationContext getWebApplicationContext(
ServletRequest request, ServletContext servletContext) throws IllegalStateException {
WebApplicationContext webApplicationContext = (WebApplicationContext) request.getAttribute(
DispatcherServlet.WEB_APPLICATION_CONTEXT_ATTRIBUTE);
if (webApplicationContext == null) {
if (servletContext == null) {
throw new IllegalStateException("No WebApplicationContext found: not in a DispatcherServlet request?");
}
webApplicationContext = WebApplicationContextUtils.getRequiredWebApplicationContext(servletContext);
}
return webApplicationContext;
}
/**
* Return the LocaleResolver that has been bound to the request by the
* DispatcherServlet.
* @param request current HTTP request
* @return the current LocaleResolver, or <code>null</code> if not found
*/
public static LocaleResolver getLocaleResolver(HttpServletRequest request) {
return (LocaleResolver) request.getAttribute(DispatcherServlet.LOCALE_RESOLVER_ATTRIBUTE);
}
/**
* Retrieves the current locale from the given request,
* using the LocaleResolver bound to the request by the DispatcherServlet
* (if available), falling back to the request's accept-header Locale.
* @param request current HTTP request
* @return the current locale, either from the LocaleResolver or from
* the plain request
* @see #getLocaleResolver
* @see javax.servlet.http.HttpServletRequest#getLocale()
*/
public static Locale getLocale(HttpServletRequest request) {
LocaleResolver localeResolver = getLocaleResolver(request);
if (localeResolver != null) {
return localeResolver.resolveLocale(request);
}
else {
return request.getLocale();
}
}
/**
* Return the ThemeResolver that has been bound to the request by the
* DispatcherServlet.
* @param request current HTTP request
* @return the current ThemeResolver, or <code>null</code> if not found
*/
public static ThemeResolver getThemeResolver(HttpServletRequest request) {
return (ThemeResolver) request.getAttribute(DispatcherServlet.THEME_RESOLVER_ATTRIBUTE);
}
/**
* Return the ThemeSource that has been bound to the request by the
* DispatcherServlet.
* @param request current HTTP request
* @return the current ThemeSource
*/
public static ThemeSource getThemeSource(HttpServletRequest request) {
return (ThemeSource) request.getAttribute(DispatcherServlet.THEME_SOURCE_ATTRIBUTE);
}
/**
* Retrieves the current theme from the given request, using the ThemeResolver
* and ThemeSource bound to the request by the DispatcherServlet.
* @param request current HTTP request
* @return the current theme, or <code>null</code> if not found
* @see #getThemeResolver
*/
public static Theme getTheme(HttpServletRequest request) {
ThemeResolver themeResolver = getThemeResolver(request);
ThemeSource themeSource = getThemeSource(request);
if (themeResolver != null && themeSource != null) {
String themeName = themeResolver.resolveThemeName(request);
return themeSource.getTheme(themeName);
}
else {
return null;
}
}
/**
* Return a read-only {@link Map} with "input" flash attributes saved on a
* previous request.
* @param request the current request
* @return a read-only Map, or {@code null}
* @see FlashMap
*/
@SuppressWarnings("unchecked")
public static Map<String, ?> getInputFlashMap(HttpServletRequest request) {
return (Map<String, ?>) request.getAttribute(DispatcherServlet.INPUT_FLASH_MAP_ATTRIBUTE);
}
/**
* Return the "output" FlashMap with attributes to save for a subsequent request.
* @param request current request
* @return a {@link FlashMap} instance, never {@code null}
* @see FlashMap
*/
public static FlashMap getOutputFlashMap(HttpServletRequest request) {
return (FlashMap) request.getAttribute(DispatcherServlet.OUTPUT_FLASH_MAP_ATTRIBUTE);
}
/**
* Return the FlashMapManager instance to save flash attributes with
* before a redirect.
* @param request the current request
*/
public static FlashMapManager getFlashMapManager(HttpServletRequest request) {
return (FlashMapManager) request.getAttribute(DispatcherServlet.FLASH_MAP_MANAGER_ATTRIBUTE);
}
}