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 */
017package org.apache.commons.jxpath.servlet;
018
019import java.util.Enumeration;
020import java.util.HashSet;
021
022import javax.servlet.ServletContext;
023
024import org.apache.commons.jxpath.DynamicPropertyHandler;
025
026/**
027 * Implementation of the {@link DynamicPropertyHandler} interface that provides
028 * access to attributes of a {@link ServletContext}.
029 *
030 * @author Dmitri Plotnikov
031 * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
032 */
033public class ServletContextHandler implements DynamicPropertyHandler {
034
035    private static final int DEFAULT_PROPERTY_COUNT = 16;
036
037    public String[] getPropertyNames(Object context) {
038        HashSet list = new HashSet(DEFAULT_PROPERTY_COUNT);
039        collectPropertyNames(list, context);
040        return (String[]) list.toArray(new String[list.size()]);
041    }
042
043    /**
044     * Collect the property names from bean, storing in set.
045     * @param set destination
046     * @param bean to read
047     */
048    protected void collectPropertyNames(HashSet set, Object bean) {
049        Enumeration e = ((ServletContext) bean).getAttributeNames();
050        while (e.hasMoreElements()) {
051            set.add(e.nextElement());
052        }
053    }
054
055    public Object getProperty(Object context, String property) {
056        return ((ServletContext) context).getAttribute(property);
057    }
058
059    public void setProperty(Object context, String property, Object value) {
060        ((ServletContext) context).setAttribute(property, value);
061    }
062}