[jdom-interest] Question about JDOMResult and usage with XMLReader

[Mario Felarca]

Hello all,

I have searched the archives, and have also compiled my own jar from the 
latest tree, but I am experiencing some weird behavior and I was hoping 
someone else may know what is causing this problem.

I have some code that is transforming data. I have an XMLReader that is 
setting an ContentHandler from a templates object as its content handler. 
The handler to that is being set as one of two things (since I was testing 
both).

The first case, which doesn't work, is when I do the following.

JDOMResult jdr = new JDOMResult();
current.setResult(jdr);

reader.parse(jds.getInputSource());

Where current is the content handler for a templates object and reader is 
the XMLReader.

This throws me the following exception on the reader.parse line.

java.lang.RuntimeException: org.xml.sax.SAXException: Ill-formed XML 
document (multiple root elements detected)
	at org.apache.xalan.transformer.TransformerImpl.run(TransformerImpl.java:3392)
	at 
org.apache.xalan.transformer.TransformerHandlerImpl.endDocument(TransformerHandlerImpl.java:433)
	at org.apache.xerces.parsers.AbstractSAXParser.endDocument(Unknown Source)
	at org.apache.xerces.impl.XMLNamespaceBinder.endDocument(Unknown Source)
	at org.apache.xerces.impl.dtd.XMLDTDValidator.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.XMLEntityManager$EntityScanner.load(Unknown Source)
	at 
org.apache.xerces.impl.XMLEntityManager$EntityScanner.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.DTDConfiguration.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)


On the other hand, if I don't use JDOMResult, and instead do the following:

ByteArrayOutputStream baos = new ByteArrayOutputStream();
                     Serializer serial = 
SerializerFactory.getSerializer(OutputProperties.getDefaultMethodProperties("xml"));
serial.setOutputStream((OutputStream)baos);

((SerializerToXML)serial).m_shouldNotWriteXMLHeader = true;

current.setResult(new SAXResult(serial.asContentHandler()));

reader.parse(jds.getInputSource());

This works if I then build a JDOMDocument using a SAXBuilder from the byte 
array that I get back.

My question I guess is two-fold. First, why does the JDOMResult not work in 
this case? Second, am I really losing any performance (either memory or 
time/processing) by going to a byte-array and then to a JDOM Document in 
two steps, as opposed to just doing a getDocument() from a JDOMResult instance?

Any thoughts or ideas would be greatly appreciated.

Thanks in advance,

Mario-