View Javadoc

1   package org.apache.anakia;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.    
20   */
21  
22  import java.util.ArrayList;
23  import java.util.Collection;
24  import java.util.Iterator;
25  
26  import org.jdom.Element;
27  
28  /**
29   * This class allows you to walk a tree of JDOM Element objects.
30   * It first walks the tree itself starting at the Element passed
31   * into allElements() and stores each node of the tree
32   * in a Vector which allElements() returns as a result of its
33   * execution. You can then use a #foreach in Velocity to walk
34   * over the Vector and visit each Element node. However, you can
35   * achieve the same effect by calling <code>element.selectNodes("//*")</code>.
36   *
37   * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
38   * @author <a href="mailto:szegedia@freemail.hu">Attila Szegedi</a>
39   * @version $Id: TreeWalker.java 524478 2007-03-31 20:51:49Z wglass $
40   */
41  public class TreeWalker
42  {
43      /**
44       * Empty constructor
45       */
46      public TreeWalker()
47      {
48          // Left blank
49      }
50  
51      /**
52       * Creates a new Vector and walks the Element tree.
53       *
54       * @param e the starting Element node
55       * @return Vector a vector of Element nodes
56       */
57      public NodeList allElements(Element e)
58      {
59          ArrayList theElements = new ArrayList();
60          treeWalk (e, theElements);
61          return new NodeList(theElements, false);
62      }
63  
64      /**
65       * A recursive method to walk the Element tree.
66       * @param Element the current Element
67       */
68      private final void treeWalk(Element e, Collection theElements )
69      {
70          for (Iterator i=e.getChildren().iterator(); i.hasNext(); )
71          {
72              Element child = (Element)i.next();
73              theElements.add(child);
74              treeWalk(child, theElements);
75          }
76      }
77  }