xtxpathprocessor.java

用Java写的面相对象的数据库管理系统

// Copyright 1997-1999 by softwarebuero m&b (SMB). All rights reserved.
//
// You can redistribute this software and/or modify it under the terms of
// the Ozone Library License version 1 published by softwarebuero m&b (SMB).
//
// $Id: XtXPathProcessor.java,v 1.6 2000/11/09 14:56:53 daniela Exp $

package org.ozoneDB.xml.xpath;

import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.Enumeration;

import org.ozoneDB.xml.dom.NodeProxy;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.traversal.NodeFilter;

import org.xml.sax.SAXException;

import com.fujitsu.xml.omquery.DomQueryMgr;


/**
 * This class implements the XPathProcessor interface on top of XT. This package
 * is provided by James Clark. Additionally the package 'omquery' is used for the
 * XPath API.
 * 
 * 
 * @version $Revision: 1.6 $ $Date: 2000/11/09 14:56:53 $
 * @author <a href="http://www.softwarebuero.de">SMB</a>
 */
public final class XtXPathProcessor extends java.lang.Object implements XPathProcessor {
    
    // Constants
    
    final static long serialVersionUID = 1;
    
    
    public XtXPathProcessor() {
    }
    
    
    public XObject execute( XPathQuery _query, Node _rootNode ) throws SAXException {
        Node namespace = _query.namespace != null ? _query.namespace : _rootNode;
        return execute( _query.qstring, _rootNode, namespace, _query.filter );
    } 
    
    
    protected XObject execute( String qString, Node rootNode, Node nameSpace, NodeFilter filter ) 
            throws org.xml.sax.SAXException {
       // System.out.println( "execute(): qstring=" + qString + ", root=" + rootNode );
        try {
            if (rootNode.getNodeType() == Node.DOCUMENT_NODE) {
                rootNode = ((Document)rootNode).getDocumentElement();
            } 
            DomQueryMgr queryMgr = new DomQueryMgr( rootNode.getOwnerDocument() );
            return new XtXObject( queryMgr.getNodesByXPath( rootNode, qString ) );
        } 
        catch (Exception e) {
           // e.printStackTrace();
            throw new org.xml.sax.SAXException( e.toString() );
        } 
    } 
    
    
    public void writeExternal( ObjectOutput out ) throws IOException {
    // nothing to do
    } 
    
    
    public void readExternal( ObjectInput in ) throws IOException, ClassNotFoundException {
    // nothing to do
    } 
    
}