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    
022    import javax.servlet.jsp.PageContext;
023    
024    import org.apache.commons.jxpath.DynamicPropertyHandler;
025    
026    /**
027     * Implementation of the {@link DynamicPropertyHandler} interface that provides
028     * access to attributes of a {@link PageContext} in all scopes.
029     *
030     * @author Dmitri Plotnikov
031     * @version $Revision: 668329 $ $Date: 2008-06-16 16:59:48 -0500 (Mon, 16 Jun 2008) $
032     */
033    public class PageContextHandler implements DynamicPropertyHandler {
034    
035        public String[] getPropertyNames(Object pageContext) {
036            HashSet list = new HashSet();
037            Enumeration e =
038                ((PageContext) pageContext).getAttributeNamesInScope(
039                    PageContext.PAGE_SCOPE);
040            while (e.hasMoreElements()) {
041                list.add(e.nextElement());
042            }
043            e =
044                ((PageContext) pageContext).getAttributeNamesInScope(
045                    PageContext.REQUEST_SCOPE);
046            while (e.hasMoreElements()) {
047                list.add(e.nextElement());
048            }
049            e =
050                ((PageContext) pageContext).getAttributeNamesInScope(
051                    PageContext.SESSION_SCOPE);
052            while (e.hasMoreElements()) {
053                list.add(e.nextElement());
054            }
055            e =
056                ((PageContext) pageContext).getAttributeNamesInScope(
057                    PageContext.APPLICATION_SCOPE);
058            while (e.hasMoreElements()) {
059                list.add(e.nextElement());
060            }
061            return (String[]) list.toArray(new String[list.size()]);
062        }
063    
064        /**
065         * Returns <code>pageContext.findAttribute(property)</code>.
066         * @param pageContext to search
067         * @param property name
068         * @return Object value
069         */
070        public Object getProperty(Object pageContext, String property) {
071            return ((PageContext) pageContext).findAttribute(property);
072        }
073    
074        public void setProperty(Object pageContext, String property, Object value) {
075            ((PageContext) pageContext).setAttribute(
076                property,
077                value,
078                PageContext.PAGE_SCOPE);
079        }
080    }