1 /*
2 * ModeShape (http://www.modeshape.org)
3 * See the COPYRIGHT.txt file distributed with this work for information
4 * regarding copyright ownership. Some portions may be licensed
5 * to Red Hat, Inc. under one or more contributor license agreements.
6 * See the AUTHORS.txt file in the distribution for a full listing of
7 * individual contributors.
8 *
9 * Unless otherwise indicated, all code in ModeShape is licensed
10 * to you under the terms of the GNU Lesser General Public License as
11 * published by the Free Software Foundation; either version 2.1 of
12 * the License, or (at your option) any later version.
13 *
14 * ModeShape is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with this software; if not, write to the Free
21 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
23 */
24 package org.modeshape.jcr;
25
26 import java.util.NoSuchElementException;
27 import javax.jcr.Node;
28 import javax.jcr.NodeIterator;
29 import net.jcip.annotations.Immutable;
30 import org.modeshape.common.util.CheckArg;
31
32 /**
33 * A concrete {@link NodeIterator} that is always empty.
34 */
35 @Immutable
36 class JcrEmptyNodeIterator implements NodeIterator {
37
38 /**
39 * {@inheritDoc}
40 *
41 * @see javax.jcr.NodeIterator#nextNode()
42 */
43 public Node nextNode() {
44 throw new NoSuchElementException();
45 }
46
47 /**
48 * {@inheritDoc}
49 *
50 * @see javax.jcr.RangeIterator#getPosition()
51 */
52 public long getPosition() {
53 return 0;
54 }
55
56 /**
57 * {@inheritDoc}
58 *
59 * @see javax.jcr.RangeIterator#getSize()
60 */
61 public long getSize() {
62 return 0;
63 }
64
65 /**
66 * {@inheritDoc}
67 *
68 * @see javax.jcr.RangeIterator#skip(long)
69 */
70 public void skip( long skipNum ) {
71 CheckArg.isNonNegative(skipNum, "skipNum");
72 if (skipNum == 0L) return;
73 throw new NoSuchElementException();
74 }
75
76 /**
77 * {@inheritDoc}
78 *
79 * @see java.util.Iterator#hasNext()
80 */
81 public boolean hasNext() {
82 return false;
83 }
84
85 /**
86 * {@inheritDoc}
87 *
88 * @see java.util.Iterator#next()
89 */
90 public Object next() {
91 throw new NoSuchElementException();
92 }
93
94 /**
95 * {@inheritDoc}
96 *
97 * @see java.util.Iterator#remove()
98 */
99 public void remove() {
100 throw new UnsupportedOperationException();
101 }
102
103 }