01: /*
02: * (c) Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Hewlett-Packard Development Company, LP
03: * All rights reserved.
04: *
05: * Redistribution and use in source and binary forms, with or without
06: * modification, are permitted provided that the following conditions
07: * are met:
08: * 1. Redistributions of source code must retain the above copyright
09: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: * 3. The name of the author may not be used to endorse or promote products
14: * derived from this software without specific prior written permission.
15:
16: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26: *
27: * NodeIterator.java
28: *
29: * Created on 28 July 2000, 13:36
30: */
31:
32: package com.hp.hpl.jena.rdf.model;
33:
34: import com.hp.hpl.jena.util.iterator.ExtendedIterator;
35: import java.util.NoSuchElementException;
36:
37: /** An iterator which returns RDF nodes.
38: *
39: * <p>RDF iterators are standard Java iterators, except that they
40: * have an extra method that returns specifically typed objects,
41: * in this case RDF nodes, and have a <CODE>close()</CODE> method.
42: * thatshould be called to free resources if the application does
43: * not complete the iteration.</p>
44: * @author bwm
45: * @version Release='$Name: $' Revision='$Revision: 1.11 $' Date='$Date: 2008/01/02 12:05:46 $'
46: */
47: public interface NodeIterator extends ExtendedIterator {
48: /** Determine if there any more values in the iteration.
49: .
50: * @return true if and only if there are more values available
51: * from the iteration.
52: */
53: public boolean hasNext();
54:
55: /** Return the next RDFNode of the iteration.
56: * @throws NoSuchElementException if there are no more nodes to be returned.
57: .
58: * @return The next RDFNode from the iteration.
59: */
60: public Object next() throws NoSuchElementException;
61:
62: /** Return the next RDFNode of the iteration.
63: * @throws NoSuchElementException if there are no more nodes to be returned.
64: .
65: * @return The next RDFNode from the iteration.
66: */
67: public RDFNode nextNode() throws NoSuchElementException;
68:
69: /** Unsupported Operation.
70: * @throws NoSuchElementException
71: */
72: public void remove() throws NoSuchElementException;
73:
74: /** Terminate the iteration and free up resources.
75: *
76: * <p>Some implementations, e.g. on relational databases, hold resources while
77: * the iterator still exists. These will normally be freed when the iteration
78: * completes. However, if an application wishes to ensure they are freed without
79: * completing the iteration, this method should be called.</p>
80: .
81: */
82: public void close();
83: }
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