001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *     http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.commons.jxpath.servlet;
018    
019    import java.util.Enumeration;
020    import java.util.HashSet;
021    import javax.servlet.http.HttpSession;
022    
023    import org.apache.commons.jxpath.JXPathException;
024    
025    /**
026     * Implementation of the {@link org.apache.commons.jxpath.DynamicPropertyHandler}
027     * interface that provides access to attributes of a @{link HttpSession}.
028     *
029     * @author Dmitri Plotnikov
030     * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
031     */
032    public class HttpSessionHandler extends ServletContextHandler {
033    
034        protected void collectPropertyNames(HashSet set, Object bean) {
035            HttpSessionAndServletContext handle =
036                (HttpSessionAndServletContext) bean;
037            super.collectPropertyNames(set, handle.getServletContext());
038            HttpSession session = handle.getSession();
039            if (session != null) {
040                Enumeration e = session.getAttributeNames();
041                while (e.hasMoreElements()) {
042                    set.add(e.nextElement());
043                }
044            }
045        }
046    
047        public Object getProperty(Object bean, String property) {
048            HttpSessionAndServletContext handle =
049                (HttpSessionAndServletContext) bean;
050            HttpSession session = handle.getSession();
051            if (session != null) {
052                Object object = session.getAttribute(property);
053                if (object != null) {
054                    return object;
055                }
056            }
057            return super.getProperty(handle.getServletContext(), property);
058        }
059    
060        public void setProperty(Object bean, String property, Object value) {
061            HttpSessionAndServletContext handle =
062                (HttpSessionAndServletContext) bean;
063            HttpSession session = handle.getSession();
064            if (session != null) {
065                session.setAttribute(property, value);
066            }
067            else {
068                throw new JXPathException("Cannot set session attribute: "
069                        + "there is no session");
070            }
071        }
072    }