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1   /**
2    * This file Copyright (c) 2011 Magnolia International
3    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
4    *
5    *
6    * This file is dual-licensed under both the Magnolia
7    * Network Agreement and the GNU General Public License.
8    * You may elect to use one or the other of these licenses.
9    *
10   * This file is distributed in the hope that it will be
11   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12   * implied warranty of MERCHANTABILITY or FITNESS FOR A
13   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14   * Redistribution, except as permitted by whichever of the GPL
15   * or MNA you select, is prohibited.
16   *
17   * 1. For the GPL license (GPL), you can redistribute and/or
18   * modify this file under the terms of the GNU General
19   * Public License, Version 3, as published by the Free Software
20   * Foundation.  You should have received a copy of the GNU
21   * General Public License, Version 3 along with this program;
22   * if not, write to the Free Software Foundation, Inc., 51
23   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24   *
25   * 2. For the Magnolia Network Agreement (MNA), this file
26   * and the accompanying materials are made available under the
27   * terms of the MNA which accompanies this distribution, and
28   * is available at http://www.magnolia-cms.com/mna.html
29   *
30   * Any modifications to this file must keep this entire header
31   * intact.
32   *
33   */
34  package info.magnolia.jcr.iterator;
35  
36  import java.util.Arrays;
37  import java.util.List;
38  
39  import javax.jcr.Node;
40  import javax.jcr.NodeIterator;
41  
42  import org.apache.commons.collections.iterators.IteratorChain;
43  /**
44   * An implementation of {@link NodeIterator} which will chain several iterators making them behave like one.
45   *
46   * @version $Id$
47   *
48   */
49  public class ChainedNodeIterator implements NodeIterator {
50  
51      private IteratorChain iterators = new IteratorChain();
52      private long position = 0;
53      private long size = 0;
54  
55      public ChainedNodeIterator(List<NodeIterator> iterators) {
56          for(NodeIterator it : iterators) {
57              this.iterators.addIterator(it);
58              size += it.getSize();
59          }
60      }
61  
62      public ChainedNodeIterator(NodeIterator... iterators) {
63          this(Arrays.asList(iterators));
64      }
65  
66      @Override
67      public void skip(long skipNum) {
68          while (skipNum > 0) {
69              next();
70              skipNum--;
71          }
72      }
73  
74      @Override
75      public long getSize() {
76          return size;
77      }
78  
79      @Override
80      public long getPosition() {
81          return position;
82      }
83  
84      @Override
85      public boolean hasNext() {
86          return iterators.hasNext();
87      }
88  
89      @Override
90      public Object next() {
91          return nextNode();
92      }
93  
94      @Override
95      public void remove() {
96          iterators.remove();
97      }
98  
99      @Override
100     public Node nextNode() {
101         Node node = (Node)iterators.next();
102         position++;
103         return node;
104     }
105 }