[jdom-interest] Writing large XML files

[New, Cecil (GEAE)]

if the output after creation of the jDOM is the file, why not just go straight
to the file and skip JDOM altogether.  XML is just text after all. :-)

-----Original Message-----
From: Subrahmanian, Sundararaman V [IT]
[mailto:sundararaman.v.subrahmanian at citigroup.com]
Sent: Tuesday, May 13, 2003 10:10 AM
To: 'jdom-interest at jdom.org'
Subject: [jdom-interest] Writing large XML files


I have a situation where I have to write a huge file.  If all the data that
is to be persisted as XML is converted to XML it might result in more than
10,000 elements.  I am pasting here a simple fragment of the code that I am
using to write the XML elements.  At some point of time, the program
suddenly aborts without any trace message.  

I am using jdom-b8 and jdk version java 1.3.1-b24.  I have the following
questions:

1.  Should I be writing the elements in smaller chunks?  If so, how do I do
it?
2.  Will going over to jdom-b9 help?  I would not want to do this right now.
3.  Also this section gets iterated over several times - is it possible that
the elements created in the previous iteration have not been freed yet by
the garbage collector and hence causing huge memory usage?

Code fragment:  (I had put 2 try-catch blocks for debugging purposes)

		Element rootElement;
		try {
			rootElement = new Element(id + m_rootElementSuffix);
			Iterator iter = beanMap.keySet().iterator();
			while (iter.hasNext()) {  // contains more than
10,000 elements
				PropertyAccessor propAcc =
(PropertyAccessor)(beanMap.get(iter.next()));
				Element element = writeElement(id, propAcc);
// writes the content of propAcc as an XML element
				rootElement.addContent(element);
			}
		} catch (Throwable t) {
			LogMgr.info(this, t.getMessage());
			throw new RuntimeException("Creating elements: " +
t.getMessage());  // t.getMessage() returns null
		}

		Writer writer = null;
		try {
			m_document.setRootElement(rootElement);  //
m_document is a class member
			m_document.setDocType(docType);
			writer = createWriter(id);
// creates a BufferedWriter
			m_outputter.output(m_document, writer);
		} catch (Throwable t) {
			LogMgr.info(this, t.getMessage());
			throw new RuntimeException("Writing elements: " +
t.getMessage());
		} finally {
			try {
				if (writer != null) { writer.close(); }
			} catch (IOException e) {
				throw new RuntimeException(e.getMessage());
			}
		}		

Any help in this regard will be appreciated.

Thanking you,
SVS
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