TreeWalker lockup Xerces1.0.1-Java

[Greg Matthews]

dear all,   we have encountered a problem with using the treewalker.   not sure if it's something we're doing wrong but the nextNode method seems like it's not finding the end of the document and just keeps looping back to the start of the doc.   if you remove any of the <c> elements in lockup.xml then it all seems to work and nextNode correctly returns the <b> node.   i'd like to know if anyone can see what we're doing wrong or if this might be a bug.   usage of attached java program:   java Loop lockup.xml   any help much appreciated,   thanks greg   platform: windows 2000, jdk1.2.2, and *not* using hotspot.

import java.io.*;
import org.w3c.dom.*;
import org.apache.xerces.domx.traversal.*;
import org.apache.xerces.dom.traversal.*;
import org.apache.xerces.dom.*;


public class Loop {

	private static Document readFile( String fileName ) throws Exception {


		org.apache.xerces.parsers.DOMParser parser = new org.apache.xerces.parsers.DOMParser();
		parser.parse( fileName );
		Document doc = parser.getDocument();
		return doc;
	}


	private static TreeWalker createTreeWalker( Node node, String nodeName ) {

		org.apache.xerces.dom.DocumentImpl docImpl = (org.apache.xerces.dom.DocumentImpl)node.getOwnerDocument();
		TreeWalker tw = docImpl.createTreeWalker( node, (short)NodeFilter.SHOW_ELEMENT, new ElementFilter( nodeName ));

		return tw;
	}


	public static void main( String args[] ) {

		try {

			Document doc = readFile( args[0] );
			TreeWalker tw = createTreeWalker( doc, "b" );

			while( true ) {

				System.out.print( "." );
				Element el = (Element)tw.nextNode();
				if( el == null ) break;

				//DEBUG
				System.out.println( "! " + el );
			}

		} catch( Exception e ) {

			e.printStackTrace();
		}
	}
}



class ElementFilter implements NodeFilter {

	private String name = null;

	public ElementFilter() {

		this(null);
	}


	public ElementFilter( String name ) {

		this.name = name;
	}


	public short acceptNode( Node n ) {

//		System.out.println( n.getNodeName());
		
		if( n.getNodeName().equals( this.name ) && n.getNodeType() == Node.ELEMENT_NODE ) {
			return FILTER_ACCEPT;
		}
		return FILTER_SKIP;
	}
}

<a>
  <b>
    <c>
      <d>
        <e/>
      </d>
      <f>
        <g/>
        <g/>
      </f>
      <h>
        <i/>
      </h>
      <j>
        <k/>
        <k/>
      </j>
    </c>
    <c>
      <d>
        <e/>
      </d>
      <f>
        <g/>
        <g/>
      </f>
      <h>
        <i/>
      </h>
      <j>
        <k/>
      </j>
    </c>
    <c>
      <d>
        <e/>
      </d>
      <l>
        <m/>
      </l>
      <f>
        <g/>
      </f>
      <h>
        <i/>
      </h>
      <j>
        <k/>
      </j>
    </c>
    <c>
      <d>
        <e/>
      </d>
      <l>
        <m/>
      </l>
      <f>
        <g/>
        <g/>
      </f>
      <h>
        <i/>
      </h>
      <j>
        <k/>
      </j>
    </c>
    <c>
      <d>
        <e/>
        <e/>
      </d>
      <j>
        <k/>
        <k/>
      </j>
    </c>
  </b>
  <n/>
</a>