01: /******************************************************************
02: * File: SingletonIterator.java
03: * Created by: Dave Reynolds
04: * Created on: 20-Jan-03
05: *
06: * (c) Copyright 2003, 2004, 2005, 2006, 2007, 2008 Hewlett-Packard Development Company, LP
07: * [See end of file]
08: * $Id: SingletonIterator.java,v 1.10 2008/01/02 12:07:36 andy_seaborne Exp $
09: *****************************************************************/package com.hp.hpl.jena.util.iterator;
10:
11: /**
12: * A ClosableIterator that contains only one element
13: *
14: * @author <a href="mailto:der@hplb.hpl.hp.com">Dave Reynolds</a>
15: * @version $Revision: 1.10 $ on $Date: 2008/01/02 12:07:36 $
16: */
17: public class SingletonIterator extends NiceIterator implements
18: ExtendedIterator {
19:
20: /** The single value to be returned */
21: private Object item;
22:
23: /** element delivered */
24: private boolean delivered = false;
25:
26: /**
27: * Constructor
28: * @param element the single value to be returned
29: */
30: public SingletonIterator(Object element) {
31: this .item = element;
32: }
33:
34: /**
35: * Can return a single value
36: */
37: public boolean hasNext() {
38: return !delivered;
39: }
40:
41: /**
42: * Return the value
43: */
44: public Object next() {
45: if (delivered)
46: return noElements("no objects in this iterator");
47: else {
48: delivered = true;
49: return item;
50: }
51: }
52:
53: }
54:
55: /*
56: (c) Copyright 2003, 2004, 2005, 2006, 2007, 2008 Hewlett-Packard Development Company, LP
57: All rights reserved.
58:
59: Redistribution and use in source and binary forms, with or without
60: modification, are permitted provided that the following conditions
61: are met:
62:
63: 1. Redistributions of source code must retain the above copyright
64: notice, this list of conditions and the following disclaimer.
65:
66: 2. Redistributions in binary form must reproduce the above copyright
67: notice, this list of conditions and the following disclaimer in the
68: documentation and/or other materials provided with the distribution.
69:
70: 3. The name of the author may not be used to endorse or promote products
71: derived from this software without specific prior written permission.
72:
73: THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
74: IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
75: OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
76: IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
77: INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
78: NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
79: DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
80: THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
81: (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
82: THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
83: */
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