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1   /*
2    * Copyright 1999-2004 The Apache Software Foundation
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.apache.commons.jxpath.servlet;
17  
18  import java.util.Enumeration;
19  import java.util.HashSet;
20  
21  import javax.servlet.jsp.PageContext;
22  
23  import org.apache.commons.jxpath.DynamicPropertyHandler;
24  
25  /***
26   * Implementation of the DynamicPropertyHandler interface that provides
27   * access to attributes of a PageContext in all scopes.
28   *
29   * @author Dmitri Plotnikov
30   * @version $Revision: 1.6 $ $Date: 2004/05/08 15:10:49 $
31   */
32  public class PageContextHandler implements DynamicPropertyHandler {
33  
34      public String[] getPropertyNames(Object pageContext) {
35          HashSet list = new HashSet();
36          Enumeration e =
37              ((PageContext) pageContext).getAttributeNamesInScope(
38                  PageContext.PAGE_SCOPE);
39          while (e.hasMoreElements()) {
40              list.add(e.nextElement());
41          }
42          e =
43              ((PageContext) pageContext).getAttributeNamesInScope(
44                  PageContext.REQUEST_SCOPE);
45          while (e.hasMoreElements()) {
46              list.add(e.nextElement());
47          }
48          e =
49              ((PageContext) pageContext).getAttributeNamesInScope(
50                  PageContext.SESSION_SCOPE);
51          while (e.hasMoreElements()) {
52              list.add(e.nextElement());
53          }
54          e =
55              ((PageContext) pageContext).getAttributeNamesInScope(
56                  PageContext.APPLICATION_SCOPE);
57          while (e.hasMoreElements()) {
58              list.add(e.nextElement());
59          }
60          return (String[]) list.toArray(new String[0]);
61      }
62  
63      /***
64       * Returns <code>pageContext.findAttribute(property)</code>.
65       */
66      public Object getProperty(Object pageContext, String property) {
67          return ((PageContext) pageContext).findAttribute(property);
68      }
69  
70      public void setProperty(
71          Object pageContext,
72          String property,
73          Object value) 
74      {
75          ((PageContext) pageContext).setAttribute(
76              property,
77              value,
78              PageContext.PAGE_SCOPE);
79      }
80  }