Why this exception?

[Per Eckerdal <ed...@shell.linux.se>]

Hello,
When I run this code,

        
System.setProperty("org.xml.sax.driver","org.apache.xerces.parsers.SAXParser");
       
        // Instantiate  a TransformerFactory.
        TransformerFactory tFactory = TransformerFactory.newInstance();
        // Determine whether the TransformerFactory supports The use uf 
SAXSource
        // and SAXResult
        if (tFactory.getFeature(SAXSource.FEATURE) && 
tFactory.getFeature(SAXResult.FEATURE))
        {
            // Cast the TransformerFactory to SAXTransformerFactory.
            SAXTransformerFactory saxTFactory = ((SAXTransformerFactory) 
tFactory);     
            // Create a TransformerHandler for each stylesheet.
            TransformerHandler tHandler1 = 
saxTFactory.newTransformerHandler(new 
StreamSource("c:\\programmering\\xml\\test\\hello.xsl"));
            //TransformerHandler tHandler2 = 
saxTFactory.newTransformerHandler(new StreamSource("foo2.xsl"));
            //TransformerHandler tHandler3 = 
saxTFactory.newTransformerHandler(new StreamSource("foo3.xsl"));
           
            // Create an XMLReader.
            XMLReader reader = XMLReaderFactory.createXMLReader();
            reader.setContentHandler(tHandler1);
            
reader.setProperty("http://xml.org/sax/properties/lexical-handler", 
tHandler1);
           
            //tHandler1.setResult(new SAXResult(tHandler2));
            //tHandler2.setResult(new SAXResult(tHandler3));
           
            // transformer3 outputs SAX events to the serializer.
            Serializer serializer = 
SerializerFactory.getSerializer(OutputPropertiesFactory.getDefaultMethodProperties("xml"));        

            serializer.setOutputStream(System.out);
            tHandler1.setResult(new 
SAXResult(serializer.asContentHandler())); // This line is changed from 
tHandler3 to tHandler1
           
            // Parse the XML input document. The input ContentHandler 
and output ContentHandler
            // work in separate threads to optimize performance.  
            reader.parse("c:\\programmering\\xml\\test\\hello.xml");
        }

I get the exception

java.lang.RuntimeException: java.lang.NullPointerException
    at org.apache.xalan.transformer.TransformerImpl.run(Unknown Source)
    at 
org.apache.xalan.transformer.TransformerHandlerImpl.endDocument(Unknown 
Source)
    at org.apache.xerces.parsers.AbstractSAXParser.endDocument(Unknown 
Source)
    at org.apache.xerces.impl.XMLDocumentScannerImpl.endEntity(Unknown 
Source)
    at org.apache.xerces.impl.XMLEntityManager.endEntity(Unknown Source)
    at org.apache.xerces.impl.XMLEntityScanner.load(Unknown Source)
    at org.apache.xerces.impl.XMLEntityScanner.skipSpaces(Unknown Source)
    at 
org.apache.xerces.impl.XMLDocumentScannerImpl$TrailingMiscDispatcher.dispatch(Unknown 
Source)
    at 
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown 
Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.DTDConfiguration.parse(Unknown Source)
    at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
    at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
    at eoner.TestClass.<init>(TestClass.java:97)
    at eoner.TestClass.main(TestClass.java:182)

I have no idea of what this is. For the ones who want to know this code 
is almost directly copied from the Pipe example, except the lines i've 
commented out and I've the line where tHandler3's result is set to the 
serializer so tHandler1's result is set to that because when I test I'm 
trying to keep things simple, so I limited the test to just one xsl file.
I'm not setting any system properties except the one I set in the first 
line of the code.
There is no code before that in the constructor of TestClass, and the 
main method do only call the constructor and catch exceptions.
/Pelle