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    
021    import javax.servlet.jsp.PageContext;
022    
023    /**
024     * A lightweight wrapper for {@link PageContext} that restricts access
025     * to attributes of the "page" scope.  This object is needed so that
026     * XPath "foo" would lookup the attribute "foo" in all scopes, while
027     * "$page/foo" would only look in the "page" scope.
028     *
029     * @author Dmitri Plotnikov
030     * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
031     */
032    public class PageScopeContext {
033        private PageContext pageContext;
034    
035        /**
036         * Create a new PageScopeContext.
037         * @param pageContext base
038         */
039        public PageScopeContext(PageContext pageContext) {
040            this.pageContext = pageContext;
041        }
042    
043        /**
044         * Returns attributes of the pageContext declared in the "page" scope.
045         * @return Enumeration of attribute names
046         */
047        public Enumeration getAttributeNames() {
048            return pageContext.getAttributeNamesInScope(PageContext.PAGE_SCOPE);
049        }
050    
051        /**
052         * Get the value of the specified attribute.
053         * @param attribute name
054         * @return Object
055         */
056        public Object getAttribute(String attribute) {
057            return pageContext.getAttribute(attribute, PageContext.PAGE_SCOPE);
058        }
059    
060        /**
061         * Set the specified attribute.
062         * @param attribute to set
063         * @param value to set
064         */
065        public void setAttribute(String attribute, Object value) {
066            pageContext.setAttribute(attribute, value, PageContext.PAGE_SCOPE);
067        }
068    }