    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}