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.jsp.PageContext;
024
025import org.apache.commons.jxpath.DynamicPropertyHandler;
026
027/**
028 * Implementation of the {@link DynamicPropertyHandler} interface that provides access to attributes of a {@link PageContext} in all scopes.
029 */
030public class PageContextHandler implements DynamicPropertyHandler {
031
032    /**
033     * Constructs a new instance.
034     */
035    public PageContextHandler() {
036        // empty
037    }
038
039    /**
040     * Returns {@code pageContext.findAttribute(property)}.
041     *
042     * @param pageContext to search
043     * @param property    name
044     * @return Object value
045     */
046    @Override
047    public Object getProperty(final Object pageContext, final String property) {
048        return ((PageContext) pageContext).findAttribute(property);
049    }
050
051    @Override
052    public String[] getPropertyNames(final Object pageContext) {
053        final HashSet<String> set = new HashSet<>();
054        Enumeration<String> e = ((PageContext) pageContext).getAttributeNamesInScope(PageContext.PAGE_SCOPE);
055        while (e.hasMoreElements()) {
056            set.add(e.nextElement());
057        }
058        e = ((PageContext) pageContext).getAttributeNamesInScope(PageContext.REQUEST_SCOPE);
059        while (e.hasMoreElements()) {
060            set.add(e.nextElement());
061        }
062        e = ((PageContext) pageContext).getAttributeNamesInScope(PageContext.SESSION_SCOPE);
063        while (e.hasMoreElements()) {
064            set.add(e.nextElement());
065        }
066        e = ((PageContext) pageContext).getAttributeNamesInScope(PageContext.APPLICATION_SCOPE);
067        while (e.hasMoreElements()) {
068            set.add(e.nextElement());
069        }
070        return set.toArray(new String[set.size()]);
071    }
072
073    @Override
074    public void setProperty(final Object pageContext, final String property, final Object value) {
075        ((PageContext) pageContext).setAttribute(property, value, PageContext.PAGE_SCOPE);
076    }
077}