001 /** 002 * JDBM LICENSE v1.00 003 * 004 * Redistribution and use of this software and associated documentation 005 * ("Software"), with or without modification, are permitted provided 006 * that the following conditions are met: 007 * 008 * 1. Redistributions of source code must retain copyright 009 * statements and notices. Redistributions must also contain a 010 * copy of this document. 011 * 012 * 2. Redistributions in binary form must reproduce the 013 * above copyright notice, this list of conditions and the 014 * following disclaimer in the documentation and/or other 015 * materials provided with the distribution. 016 * 017 * 3. The name "JDBM" must not be used to endorse or promote 018 * products derived from this Software without prior written 019 * permission of Cees de Groot. For written permission, 020 * please contact cg@cdegroot.com. 021 * 022 * 4. Products derived from this Software may not be called "JDBM" 023 * nor may "JDBM" appear in their names without prior written 024 * permission of Cees de Groot. 025 * 026 * 5. Due credit should be given to the JDBM Project 027 * (http://jdbm.sourceforge.net/). 028 * 029 * THIS SOFTWARE IS PROVIDED BY THE JDBM PROJECT AND CONTRIBUTORS 030 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT 031 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 032 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 033 * CEES DE GROOT OR ANY CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 034 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 035 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 036 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 037 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 038 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 039 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 040 * OF THE POSSIBILITY OF SUCH DAMAGE. 041 * 042 * Copyright 2001 (C) Alex Boisvert. All Rights Reserved. 043 * Contributions are Copyright (C) 2001 by their associated contributors. 044 * 045 */ 046 047 package jdbm.helper; 048 049 import java.io.IOException; 050 051 /** 052 * Browser to traverse a collection of tuples. The browser allows for 053 * forward and reverse order traversal. 054 * 055 * @author <a href="mailto:boisvert@intalio.com">Alex Boisvert</a> 056 * @version $Id: TupleBrowser.java,v 1.2 2001/05/19 14:02:00 boisvert Exp $ 057 */ 058 public abstract class TupleBrowser { 059 060 /** 061 * Get the next tuple. 062 * 063 * @param tuple Tuple into which values are copied. 064 * @return True if values have been copied in tuple, or false if there is 065 * no next tuple. 066 */ 067 public abstract boolean getNext( Tuple tuple ) 068 throws IOException; 069 070 071 /** 072 * Get the previous tuple. 073 * 074 * @param tuple Tuple into which values are copied. 075 * @return True if values have been copied in tuple, or false if there is 076 * no previous tuple. 077 */ 078 public abstract boolean getPrevious( Tuple tuple ) 079 throws IOException; 080 081 }