001/* 002 * Copyright 2002-2014 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.support; 018 019import java.util.List; 020 021import javax.servlet.http.HttpServletRequest; 022import javax.servlet.http.HttpServletResponse; 023import javax.servlet.http.HttpSession; 024 025import org.springframework.lang.Nullable; 026import org.springframework.web.servlet.FlashMap; 027import org.springframework.web.util.WebUtils; 028 029/** 030 * Store and retrieve {@link FlashMap} instances to and from the HTTP session. 031 * 032 * @author Rossen Stoyanchev 033 * @author Juergen Hoeller 034 * @since 3.1.1 035 */ 036public class SessionFlashMapManager extends AbstractFlashMapManager { 037 038 private static final String FLASH_MAPS_SESSION_ATTRIBUTE = SessionFlashMapManager.class.getName() + ".FLASH_MAPS"; 039 040 041 /** 042 * Retrieves saved FlashMap instances from the HTTP session, if any. 043 */ 044 @Override 045 @SuppressWarnings("unchecked") 046 @Nullable 047 protected List<FlashMap> retrieveFlashMaps(HttpServletRequest request) { 048 HttpSession session = request.getSession(false); 049 return (session != null ? (List<FlashMap>) session.getAttribute(FLASH_MAPS_SESSION_ATTRIBUTE) : null); 050 } 051 052 /** 053 * Saves the given FlashMap instances in the HTTP session. 054 */ 055 @Override 056 protected void updateFlashMaps(List<FlashMap> flashMaps, HttpServletRequest request, HttpServletResponse response) { 057 WebUtils.setSessionAttribute(request, FLASH_MAPS_SESSION_ATTRIBUTE, (!flashMaps.isEmpty() ? flashMaps : null)); 058 } 059 060 /** 061 * Exposes the best available session mutex. 062 * @see org.springframework.web.util.WebUtils#getSessionMutex 063 * @see org.springframework.web.util.HttpSessionMutexListener 064 */ 065 @Override 066 protected Object getFlashMapsMutex(HttpServletRequest request) { 067 return WebUtils.getSessionMutex(request.getSession()); 068 } 069 070}