/**
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided
* that the following conditions are met:
*
* 1. Redistributions of source code must retain copyright
* statements and notices. Redistributions must also contain a
* copy of this document.
*
* 2. Redistributions in binary form must reproduce the
* above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* 3. The name "Exolab" must not be used to endorse or promote
* products derived from this Software without prior written
* permission of Intalio, Inc. For written permission,
* please contact info@exolab.org.
*
* 4. Products derived from this Software may not be called "Exolab"
* nor may "Exolab" appear in their names without prior written
* permission of Intalio, Inc. Exolab is a registered
* trademark of Intalio, Inc.
*
* 5. Due credit should be given to the Exolab Project
* (http://www.exolab.org/).
*
* THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* INTALIO, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Copyright 1999 (C) Intalio, Inc. All Rights Reserved.
*
* $Id$
*/
package org.exolab.castor.jdo;
import java.util.Enumeration;
import java.util.NoSuchElementException;
/**
* An iteration of the results of a query. This interface provides the
* ability to move forward only in the result set and pick the next
* result and close it.
*
* @author <a href="arkin@intalio.com">Assaf Arkin</a>
* @version $Revision$ $Date: 2004-05-03 16:05:30 -0600 (Mon, 03 May 2004) $
*/
public interface QueryResults extends Enumeration<Object> {
/**
* Returns true if there are any more results in the result set.
* If an error occured reading the last result, an exception will
* be thrown and the result set cannot be used further.
*
* @return True if there are any more results in the result set
* @throws PersistenceException An error with the persistence engine
*/
boolean hasMore() throws PersistenceException;
/**
* Returns the next result in the result set. If there are no
* more results (a previous cal to {@link #hasMore} returns
* false) this method will throw an exceptin. If an error
* occured reading the last result, an exception will be
* thrown and the result set cannot be used further.
*
* @return The next result in the result set
* @throws PersistenceException An error with the persistence
* engine
* @throws NoSuchElementException There are no more results in
* the result set
*/
Object next() throws PersistenceException, NoSuchElementException;
/**
* Closes the result set and releases all resources held by it.
*/
void close();
/**
* moves the result of the query to the absolute position in the
* resultset.
*
* @param row The row to move to
* @return ???
* @throws PersistenceException A persistence error occured
*/
boolean absolute(int row) throws PersistenceException;
/**
* Finds the size of the resulting resultset from the query.
*
* @return Size of the resulting result set.
* @throws PersistenceException A persistence error occured
*/
int size() throws PersistenceException;
}