XSLTC provides intractable DTMAxisIterNodeList to function call

James Prosser Fri, 08 Sep 2006 04:21:07 -0700

Hi folks,

The following code demonstrates a stylesheet successfully executingunder Xalan-Java Interpretive and failing under XSLTC. The problemappears to lie with the Nodeset passed by XSL java extensions tostatic methods. When interpreted I get a DTMNodeList which can bewrangled into a Node. Under XSLTC I get a DTMAxisIterNodeList whichmeets all my attempts to inspect it with null pointer andarrayOutOfBounds exceptions.

The intention of the technique shown here is to allow an arbitrarynumber of named arguements to be passed to a single resolve method.


Any help would be appreciated.

Regards,

James Prosser

Pasted below are:
1. test.xml a document to transform
2. test.xsl a stylesheet that demonstrating technique (in a raw form).
3. Test.java applies test.xsl to test.xml and provides a method called
   by  test.xsl.
4. The winXP command lines used to compile and run code.
5. The results of running Test.java
6. My environment

1. test.xml===================================================================

<?xml version='1.0' encoding='UTF-8'?>
<client ClientID="123456">
   <initial-consult>
      <diagnosis>Autism</diagnosis>
   </initial-consult>
</client>

2. test.xsl===================================================================

<?xml version='1.0' encoding='UTF-8'?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
                xmlns:xalan="http://xml.apache.org/xalan";

xmlns:test="http://xml.apache.org/xalan/au.com.portal.test.xsltc";

                version='1.0'>

   <xsl:template match="client">
      <xsl:variable name="args">
         <args sub-view="client-details.xml">
            <arg param="ClientID"><xsl:value-of select="@ClientID"/></arg>
            <arg param="Service">Ambulatory</arg>
         </args>
      </xsl:variable>

      <report>
         <xsl:copy-of select="test:Test.resolve(xalan:nodeset($args)/args)"/>
         <flag>
            <xsl:value-of select="initial-consult/diagnosis"/>
         </flag>
      </report>
   </xsl:template>
</xsl:stylesheet>

3. Test.java==================================================================

package au.com.portal.test.xsltc;

// Sun Java API
import java.io.FileOutputStream;
import java.io.StringWriter;
import java.util.Properties;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

public class Test {

   // values for property javax.xml.transform.TransformerFactory

static String interpreted ="org.apache.xalan.processor.TransformerFactoryImpl";static String compiled ="org.apache.xalan.xsltc.trax.TransformerFactoryImpl";


   // Local file names of input and output files.
   static String xslInURI = "test.xsl";
   static String xmlInURI = "test.xml";
   static String interpretedOutURI = "interpreted.xml";
   static String compiledOutURI = "compiled.xml";

   // document: return a namespace aware Document ==========================
   private static Document document() {
      DocumentBuilder docBuilder = null;
      try { DocumentBuilderFactory fac = DocumentBuilderFactory.newInstance();
            fac.setNamespaceAware(true);
            docBuilder = fac.newDocumentBuilder();
      }
      catch (Exception e) {e.printStackTrace();}
      return docBuilder.newDocument();
   }

   // printNode: print node to System.out ===================================
   private static void printNode(Node node) throws Exception {
      StringWriter stringWriter = new StringWriter();
      Transformer t = TransformerFactory.newInstance().newTransformer();
      t.transform(new DOMSource(node),
                  new StreamResult(stringWriter));
      System.out.println(stringWriter.toString());
   }

   // transform: perform transformation =====================================
   private static void transform(String outURI) throws Exception {
      TransformerFactory tFactory = TransformerFactory.newInstance();

Transformer t = tFactory.newTransformer(newStreamSource(Test.xslInURI));

      t.transform(new StreamSource(Test.xmlInURI),
                  new StreamResult(new FileOutputStream(outURI)));
   }

   // resolve: method called by test.xsl ====================================
   // A useful resolve would return XML generated by a named template whose
   // params are bound by values in nodelist. Here we just return the args.
   public static Node resolve(NodeList nodeList) throws Exception {
      System.out.println("--" + nodeList + "--");
      // Retrieves Element from org.apache.xml.dtm.ref.DTMNodeList in
      // interpreted mode but fails org.apache.xml.dtm.ref.DTMAxisIterNodeList
      // in compiled mode.
      Element viewElement = (Element) (document().importNode(nodeList.item(0),
                                                             true));
      printNode(viewElement);     // trace statement
      return viewElement;
   }

   // main ==================================================================
   public static void main(String[] args) throws Exception {

System.out.println("---- Interpreted transform------------------------");

         System.setProperty("javax.xml.transform.TransformerFactory",
                         interpreted);
      transform(interpretedOutURI);

System.out.println("---- Compiled transform---------------------------");

         System.setProperty("javax.xml.transform.TransformerFactory",
                         compiled);
      transform(compiledOutURI);
      System.out.println("Goodbye");
   }
}

4. Compile and run command lines used under Windows XP========================

    REM Compile
    e:
    SET XSLTCPATH=e:\cherrywood\test-bench\xsltc
    SET JARPATH=%XSLTCPATH%\jar

SETCLASSPATH=.;%JARPATH%\xalan.jar;%JARPATH%\serializer.jar;%JARPATH%\xercesImpl.jar;%JARPATH%\xml-apis.jar;

    cd %XSLTCPATH%\au\com\portal\test\xsltc
    javac Test.java

    REM Run
    e:
    SET XSLTCPATH=e:\cherrywood\test-bench\xsltc
    SET JARPATH=%XSLTCPATH%\jar

SETCLASSPATH=.;%JARPATH%\xalan.jar;%JARPATH%\serializer.jar;%JARPATH%\xercesImpl.jar;%JARPATH%\xml-apis.jar;

    cd %XSLTCPATH%
    java au.com.portal.test.xsltc.Test

5. Output from running Test.java==============================================

---- Interpreted transform ------------------------
[EMAIL PROTECTED]

<?xml version="1.0" encoding="UTF-8"?><argssub-view="client-details.xml"><arg p

aram="ClientID">123456</arg><arg param="Service">Ambulatory</arg></args>
---- Compiled transform ---------------------------
[EMAIL PROTECTED]
ERROR:  ''

Exception in thread "main" javax.xml.transform.TransformerException:java.lang.N

ullPointerException