Using transform api with xslt and DOM Nodes

Question

Hi,
when trying to transform a xml document with xslt using the javax.xml.transform api
providing an element node of a previously parsed document, I find that absolute
paths are not recognized.
The following program shows what I am basically doing (the class can be executed
on the command line providing a stylesheet and xml instance):
import java.io.*;
import org.w3c.dom.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.stream.*;
import javax.xml.parsers.*;
class Transform {
public static void main(String [] args) throws Exception {
     TransformerFactory tfactory = TransformerFactory.newInstance();
     Transformer transformer = tfactory.newTransformer(new StreamSource(args[0]));
     DocumentBuilderFactory dfactory = DocumentBuilderFactory.newInstance();
     DocumentBuilder parser = dfactory.newDocumentBuilder();
     Document doc = parser.parse(args[1]);
     Element domElem = doc.getDocumentElement();
     // workaround
//     StringWriter out = new StringWriter();
//     Transformer id = tfactory.newTransformer();
//     id.transform(new DOMSource(domElem),new StreamResult(out));
//     String xml = out.toString();
//     transformer.transform(new StreamSource(new StringReader(xml)), new StreamResult(System.out));
     transformer.transform(new DOMSource(domElem), new StreamResult(System.out));
transformer.clearParameters();
If I use this on e.g.
xsl:
<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes" encoding="ISO-8859-1" method="xml"/>
<xsl:template match="/">
<xsl:value-of select="/foo/bar"/>
</xsl:template>
</xsl:stylesheet>
xml:
<foo>abc<bar>def</bar></foo>
I get
<?xml version="1.0" encoding="ISO-8859-1"?>
abcdef
instead of
<?xml version="1.0" encoding="ISO-8859-1"?>
def
I think this is due to the fact, that the transformation does not recognize
any absolutely adressed xpath correctly.
From what I read in the API docs, I think what I'm doing should be ok.
So: did I misunderstand something or is this a bug in the java libraries?
I'm using j2sdk 1.4.1_01 on i386 linux.
If I use the commented code (serializing the xml and doing the transformation
with a StreamSource, that has to be parsed again), everything's fine.
Of course it would be easier to parse the file directly in the example but in the
real program, I already have a dom tree and want to transform a part of it.
Any help appreciated.
Thanks, Morus

Answer 1

why?
that's all the point of XSL: define what part of your
XML you want in your XSL templates, there is no need
to prepare a sub-DOM of your DOM.
Ok. Right. That's an alternative.
The problem remains, that there are some stylesheets originally written
for the current solution and though they should work with the whole document
as well, it's not certain.
Actually I don't know if this ever worked. I did neither write this code nor maintained the system so far.
btw. you would be faster by giving a StreamSource to
your transformation.Probably yes. But that would imply to rewrite a lot of code.
What is happening is:
there is a SOAP answser containing a xml document as the result parameter.
The SOAP answer is parsed (I guess by the soap classes already) and the
result xml is extracted. That's where the element node I'm trying to transform
stems from.
Besides, I still don't see why DOMSource takes any node if only document nodes
work.
Thanks, Morus