1 /*
2 * Copyright (c) 2007, James Leigh All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * - Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 * - Redistributions in binary form must reproduce the above copyright notice,
10 * this list of conditions and the following disclaimer in the documentation
11 * and/or other materials provided with the distribution.
12 * - Neither the name of the openrdf.org nor the names of its contributors may
13 * be used to endorse or promote products derived from this software without
14 * specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 *
28 */
29 package org.openrdf.elmo.sesame.iterators;
30
31 import java.io.Closeable;
32 import java.io.IOException;
33 import java.util.Iterator;
34
35 /**
36 * Converts the delegate iterator into the result type.
37 *
38 * @author James Leigh
39 *
40 * @param <S>
41 * @param <E>
42 */
43 public abstract class ConvertingIterator<S, E> implements Iterator<E>,
44 Closeable {
45 private Iterator<S> delegate;
46
47 public ConvertingIterator(Iterator<S> delegate) {
48 super();
49 this.delegate = delegate;
50 }
51
52 public boolean hasNext() {
53 return delegate.hasNext();
54 }
55
56 public E next() {
57 return convert(delegate.next());
58 }
59
60 public void remove() {
61 delegate.remove();
62 }
63
64 public void close() throws IOException {
65 if (delegate instanceof Closeable)
66 ((Closeable) delegate).close();
67 }
68
69 protected abstract E convert(S element);
70
71 }