RE: [xsl] TransformerHandler Chaining with Java and Saxon

["Michael Kay" <mike@xxxxxxxxxxxx>]

Could be this bug

https://sourceforge.net/tracker/index.php?func=detail&aid=1558231&group_id=2
9872&atid=397617

though that's documented as applying to 8.8 rather than 8.9.

Another candidate is this one, in 9.0

https://sourceforge.net/tracker/?func=detail&aid=1986836&group_id=29872&atid
=397617

I suggest you try it on a more recent release. The current release is
9.1.0.6.

Also, I suggest you raise Saxon-specific problems on the saxon-help list at
SourceForge.

Regards,

Michael Kay
http://www.saxonica.com/
http://twitter.com/michaelhkay  

> -----Original Message-----
> From: Scott Lynch [mailto:slynch@xxxxxxxxxx] 
> Sent: 02 June 2009 23:50
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject: [xsl] TransformerHandler Chaining with Java and Saxon
> 
> All,
> 
> This is not quite an xsl question, but hopefully someone here 
> has seen this before and can help me, because I've been 
> banging my head on my keyboard for hours now. I'm trying to 
> chain together several transforms using the 
> TransformerHandler chaining design pattern in Java with the 
> Saxon (8.9) engine. The code below invariable throws an 
> exception complaining about "The TransformerHandler is not 
> serially reusable. The
> startDocument() method must be called once only." when the
> reader.parse(source) method is invoked. 
> 
> Does anyone know why this would be happening and how to 
> prevent it? I am able to individually transform my file with 
> the transforms by using a set of rotating temporary files, 
> but I would like to increase the speed of the transformation 
> (I'm transforming about 17 files comprising 50meg of data 
> through about 10 transforms and this is taking several 
> minutes) using chaining if possible.
> 
> thanks,
> Scott
> 
> 
>     private String multiTransform(String sourceFileName, 
> List<String> transformFiles, String startKey)
>     {
>         String outFileName = "transformOutput.xml";
>         try
>         {
>             TransformerFactory factory = 
> TransformerFactory.newInstance();
>             SAXTransformerFactory saxTFactory = 
> ((SAXTransformerFactory) factory);
>             List<TransformerHandler> handlers = new 
> ArrayList<TransformerHandler>();
>             TransformerHandler previousHandler = null;
>             for (String transformFile : transformFiles)
>             {
>                 StreamSource source = new 
> StreamSource(Resources.getResource(transformFile).openStream());
>                 TransformerHandler handler = 
> saxTFactory.newTransformerHandler(source);
>                 handlers.add(handler);
>                 if (previousHandler != null)
>                 {
>                     previousHandler.setResult(new SAXResult(handler));
>                     break;
>                 }
>                 previousHandler = handler;
>             }
> 
>             XMLReader reader = XMLReaderFactory.createXMLReader();
>             reader.setContentHandler(handlers.get(0));
> 
>             TransformerHandler lastHandler =
> handlers.get(handlers.size() - 1);
>             OutputStream resultOutStream = new 
> FileOutputStream(outFileName);
>             StreamResult xformOutResult = new 
> StreamResult(resultOutStream);
>             lastHandler.setResult(xformOutResult);
>             FileInputStream fileInStrm = new 
> FileInputStream(sourceFileName);
>             InputSource source = new InputSource(fileInStrm);
>             reader.parse(source);
>         }
>         catch (Exception e)
>         {
>             e.printStackTrace();
>         }
>         return outFileName;
>     }
> 
> 
> 
> The exception...
> 
> java.lang.UnsupportedOperationException: The 
> TransformerHandler is not serially reusable. The 
> startDocument() method must be called once only.
> 	at
> net.sf.saxon.TransformerHandlerImpl.startDocument(TransformerH
> andlerImpl
> .java:69)
> 	at
> net.sf.saxon.event.ContentHandlerProxy.open(ContentHandlerProx
> y.java:242
> )
> 	at net.sf.saxon.event.ProxyReceiver.open(ProxyReceiver.java:76)
> 	at
> net.sf.saxon.event.ImplicitResultChecker.open(ImplicitResultCh
> ecker.java
> :24)
> 	at
> net.sf.saxon.event.ImplicitResultChecker.firstContent(Implicit
> ResultChec
> ker.java:59)
> 	at
> net.sf.saxon.event.ImplicitResultChecker.startElement(Implicit
> ResultChec
> ker.java:30)
> 	at
> net.sf.saxon.event.NamespaceReducer.startElement(NamespaceRedu
> cer.java:5
> 4)
> 	at
> net.sf.saxon.event.ComplexContentOutputter.startContent(Comple
> xContentOu
> tputter.java:481)
> 	at
> net.sf.saxon.event.ComplexContentOutputter.characters(ComplexC
> ontentOutp
> utter.java:136)
> 	at net.sf.saxon.instruct.Copy.processLeavingTail(Copy.java:164)
> 	at
> net.sf.saxon.instruct.Choose.processLeavingTail(Choose.java:338)
> 	at
> net.sf.saxon.instruct.Template.applyLeavingTail(Template.java:99)
> 	at
> net.sf.saxon.instruct.ApplyTemplates.applyTemplates(ApplyTempl
> ates.java:
> 319)
> 	at
> net.sf.saxon.instruct.ApplyTemplates.apply(ApplyTemplates.java:189)
> 	at
> net.sf.saxon.instruct.ApplyTemplates.process(ApplyTemplates.java:149)
> 	at
> net.sf.saxon.instruct.ElementCreator.processLeavingTail(Elemen
> tCreator.j
> ava:250)
> 	at net.sf.saxon.instruct.Copy.processLeavingTail(Copy.java:152)
> 	at
> net.sf.saxon.instruct.Choose.processLeavingTail(Choose.java:338)
> 	at
> net.sf.saxon.instruct.Template.applyLeavingTail(Template.java:99)
> 	at
> net.sf.saxon.instruct.ApplyTemplates.applyTemplates(ApplyTempl
> ates.java:
> 319)
> 	at
> net.sf.saxon.instruct.ApplyTemplates.defaultAction(ApplyTempla
> tes.java:3
> 51)
> 	at
> net.sf.saxon.instruct.ApplyTemplates.applyTemplates(ApplyTempl
> ates.java:
> 312)
> 	at
> net.sf.saxon.Controller.transformDocument(Controller.java:1602)
> 	at
> net.sf.saxon.TransformerHandlerImpl.endDocument(TransformerHan
> dlerImpl.j
> ava:133)
> 	at
> com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.e
> ndDocument
> (AbstractSAXParser.java:737)
> 	at
> com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentSca
> nnerImpl.s
> canDocument(XMLDocumentFragmentScannerImpl.java:515)
> 	at
> com.sun.org.apache.xerces.internal.parsers.XML11Configuration.
> parse(XML1
> 1Configuration.java:807)
> 	at
> com.sun.org.apache.xerces.internal.parsers.XML11Configuration.
> parse(XML1
> 1Configuration.java:737)
> 	at
> com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XML
> Parser.jav
> a:107)
> 	at
> com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.p
> arse(Abstr
> actSAXParser.java:1205)