xobject.java

用Java写的面相对象的数据库管理系统

// You can redistribute this software and/or modify it under the terms of
// the Ozone Library License version 1 published by ozone-db.org.
//
// The original code and portions created by SMB are
// Copyright (C) 1997-2000 by SMB GmbH. All rights reserved.
//
// $Id: XObject.java,v 1.4 2000/10/28 16:55:25 daniela Exp $

package org.ozoneDB.xml.xpath;

import java.io.Serializable;

import org.w3c.dom.DocumentFragment;
import org.w3c.dom.NodeList;


/**
 * This common interface insulates the different XPath query results. The
 * interface must be implemented for each XPath engine like Xalan or XT. The
 * interface provides methods for getting the native result type.
 * 
 * 
 * @version $Revision: 1.4 $ $Date: 2000/10/28 16:55:25 $
 * @author <a href="http://www.softwarebuero.de">SMB</a>
 */
public interface XObject extends Serializable {
    
    // result class type
    public final static int CLASS_NULL = -1;
    
    public final static int CLASS_UNKNOWN = 0;
    
    public final static int CLASS_BOOLEAN = 1;
    
    public final static int CLASS_NUMBER = 2;
    
    public final static int CLASS_STRING = 3;
    
    public final static int CLASS_NODESET = 4;
    
    public final static int CLASS_RTREEFRAG = 5;
    
    
    /**
     * Tell what kind of class this is.
     */
    public int getType();
    
    
    /**
     * Cast result object to a boolean.
     */
    public boolean bool() throws org.xml.sax.SAXException;
    
    
    /**
     * Cast result object to a number.
     */
    public double num() throws org.xml.sax.SAXException;
    
    
    /**
     * Cast result object to a string.
     */
    public String str();
    
    
    /**
     * Cast result object to a nodelist.
     */
    public NodeList nodeset() throws org.xml.sax.SAXException;
    
    
    /**
     * Cast result object to a result tree fragment.
     */
    public DocumentFragment rtree();
    
}