    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
    018package org.apache.commons.jxpath.servlet;
    019
    020import java.util.Enumeration;
    021import java.util.HashSet;
    022
    023import javax.servlet.ServletContext;
    024
    025import org.apache.commons.jxpath.DynamicPropertyHandler;
    026
    027/**
    028 * Implementation of the {@link DynamicPropertyHandler} interface that provides access to attributes of a {@link ServletContext}.
    029 */
    030public class ServletContextHandler implements DynamicPropertyHandler {
    031
    032    private static final int DEFAULT_PROPERTY_COUNT = 16;
    033
    034    /**
    035     * Constructs a new instance.
    036     */
    037    public ServletContextHandler() {
    038        // empty
    039    }
    040
    041    /**
    042     * Collect the property names from bean, storing in set.
    043     *
    044     * @param set  destination
    045     * @param bean to read
    046     */
    047    protected void collectPropertyNames(final HashSet<String> set, Object bean) {
    048        if (bean instanceof HttpSessionAndServletContext) {
    049            bean = ((HttpSessionAndServletContext) bean).getServletContext();
    050        }
    051        final Enumeration<String> e = ((ServletContext) bean).getAttributeNames();
    052        while (e.hasMoreElements()) {
    053            set.add(e.nextElement());
    054        }
    055    }
    056
    057    @Override
    058    public Object getProperty(final Object context, final String property) {
    059        return ((ServletContext) context).getAttribute(property);
    060    }
    061
    062    @Override
    063    public String[] getPropertyNames(final Object context) {
    064        final HashSet<String> set = new HashSet<>(DEFAULT_PROPERTY_COUNT);
    065        collectPropertyNames(set, context);
    066        return set.toArray(new String[set.size()]);
    067    }
    068
    069    @Override
    070    public void setProperty(final Object context, final String property, final Object value) {
    071        ((ServletContext) context).setAttribute(property, value);
    072    }
    073}