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