selector.java

来自「这是外国一个开源推理机」· Java 代码 · 共 57 行

/*  Sesame - Storage and Querying architecture for RDF and RDF Schema
 *  Copyright (C) 2001-2005 Aduna
 *
 *  Contact: 
 *  	Aduna
 *  	Prinses Julianaplein 14 b
 *  	3817 CS Amersfoort
 *  	The Netherlands
 *  	tel. [phone]
 *  	fax. [phone]
 *
 *  	http://aduna.biz/
 *  	http://www.openrdf.org/
 *  
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.openrdf.sesame.query.rql.model;

import org.openrdf.sesame.query.QueryEvaluationException;
import org.openrdf.sesame.sail.RdfSchemaSource;

public interface Selector {

	/**
	 * Gives the Selector the opportunity to initialize itself.
	 **/
	public void initialize(RdfSchemaSource rss)
		throws QueryEvaluationException;

	/**
	 * Selects the next values. Returns true if the selection was
	 * successful, false otherwise.
	 **/
	public boolean selectNext(RdfSchemaSource rss)
		throws QueryEvaluationException;

	/**
	 * Clears the Selector. The Selector will release all resources
	 * it is currently using. After the Selector has been cleared it
	 * should be reusable by re-initializing it.
	 **/
	public void clear();
}