01: /**
02: * JDBM LICENSE v1.00
03: *
04: * Redistribution and use of this software and associated documentation
05: * ("Software"), with or without modification, are permitted provided
06: * that the following conditions are met:
07: *
08: * 1. Redistributions of source code must retain copyright
09: * statements and notices. Redistributions must also contain a
10: * copy of this document.
11: *
12: * 2. Redistributions in binary form must reproduce the
13: * above copyright notice, this list of conditions and the
14: * following disclaimer in the documentation and/or other
15: * materials provided with the distribution.
16: *
17: * 3. The name "JDBM" must not be used to endorse or promote
18: * products derived from this Software without prior written
19: * permission of Cees de Groot. For written permission,
20: * please contact cg@cdegroot.com.
21: *
22: * 4. Products derived from this Software may not be called "JDBM"
23: * nor may "JDBM" appear in their names without prior written
24: * permission of Cees de Groot.
25: *
26: * 5. Due credit should be given to the JDBM Project
27: * (http://jdbm.sourceforge.net/).
28: *
29: * THIS SOFTWARE IS PROVIDED BY THE JDBM PROJECT AND CONTRIBUTORS
30: * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
31: * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
32: * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
33: * CEES DE GROOT OR ANY CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
34: * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
35: * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
36: * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
38: * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
39: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
40: * OF THE POSSIBILITY OF SUCH DAMAGE.
41: *
42: * Copyright 2001 (C) Alex Boisvert. All Rights Reserved.
43: * Contributions are Copyright (C) 2001 by their associated contributors.
44: *
45: */package jdbm.helper;
46:
47: import java.io.IOException;
48:
49: /**
50: * Browser to traverse a collection of tuples. The browser allows for
51: * forward and reverse order traversal.
52: *
53: * @author <a href="mailto:boisvert@intalio.com">Alex Boisvert</a>
54: * @version $Id: TupleBrowser.java,v 1.2 2001/05/19 14:02:00 boisvert Exp $
55: */
56: public abstract class TupleBrowser {
57:
58: /**
59: * Get the next tuple.
60: *
61: * @param tuple Tuple into which values are copied.
62: * @return True if values have been copied in tuple, or false if there is
63: * no next tuple.
64: */
65: public abstract boolean getNext(Tuple tuple) throws IOException;
66:
67: /**
68: * Get the previous tuple.
69: *
70: * @param tuple Tuple into which values are copied.
71: * @return True if values have been copied in tuple, or false if there is
72: * no previous tuple.
73: */
74: public abstract boolean getPrevious(Tuple tuple) throws IOException;
75:
76: }
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