Hallo Rick,
Thanks for your reply. I added your suggested lines to the code, but I see no
speed increase at all. Just to make sure, here's the code I use for parsing
now:
if (docbuilder == null) {
System.setProperty("javax.xml.transform.TransformerFactory",
"org.apache.xalan.processor.TransformerFactoryImpl");
System.setProperty("org.apache.xml.dtm.DTMManager",
"org.apache.xml.dtm.ref.DTMManagerDefault");
System.setProperty("javax.xml.parsers.DocumentBuilderFactory",
"org.apache.xerces.jaxp.DocumentBuilderFactoryImpl");
System.setProperty("javax.xml.parsers.SAXParserFactory",
"org.apache.xerces.jaxp.SAXParserFactoryImpl");
System.setProperty(
"org.apache.xerces.xni.parser.XMLParserConfiguration",
"org.apache.xerces.parsers.XML11Configuration");
DocumentBuilderFactory factory = DocumentBuilderFactory
.newInstance();
System.out.println(factory);
factory.setNamespaceAware(true);
factory.setValidating(false);
factory.setExpandEntityReferences(false);
docbuilder = factory.newDocumentBuilder();
docbuilder.setErrorHandler(errorHandler);
System.out.println(docbuilder);
}
InputSource is = new InputSource(rwm);
// output that measures the DOM parse time
long t = System.currentTimeMillis();
doc = docbuilder.parse(is);
t = System.currentTimeMillis()-t;
System.out.println("parseTime: "+String.valueOf(t));
Could the DOCTYPE declaration have anything to do with it?
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd";>
Cheers, Jos
PS, parsing the file with the qt library takes ~7 ms...
On Monday 14 February 2005 13:14, Rick Bullotta wrote:
> Add these system properties to your code and you may see a DRAMATIC
> increase in performance in DOM creation as well as Xpath and Transformer
> creation. Using this technique bypasses a lot of very expensive factory
> overhead which involves searching in the JAR file and the classpath for
> configuration information.
>
> // Xalan
>
> System.setProperty("javax.xml.transform.TransformerFactory",
> "org.apache.xalan.processor.TransformerFactoryImpl");
>
> System.setProperty("org.apache.xml.dtm.DTMManager",
> "org.apache.xml.dtm.ref.DTMManagerDefault");
>
> // Xerces
>
> System.setProperty("javax.xml.parsers.DocumentBuilderFactory",
> "org.apache.xerces.jaxp.DocumentBuilderFactoryImpl");
>
> System.setProperty("javax.xml.parsers.SAXParserFactory",
> "org.apache.xerces.jaxp.SAXParserFactoryImpl");
>
> System.setProperty("org.apache.xerces.xni.parser.XMLParserConfiguration",
> "org.apache.xerces.parsers.XML11Configuration");
>
>
> Rick Bullotta
> CTO
> Lighthammer Software (http://www.lighthammer.com)
>
> -----Original Message-----
> From: Jos van den Oever [mailto:[EMAIL PROTECTED]
> Sent: Monday, February 14, 2005 6:56 AM
> To: [EMAIL PROTECTED]
> Subject: Re: dom build speed
>
> > I've run up against this problem as well. If I'm not mistaken, the
> > problem is the way Xerces handles setting properties on a DOM parser
> > via the JAXP interfaces. Xerces will create a new instance (!) of the
> > DOMParser class for every single property you set (i.e., via
> > setValidating(), setNamespaceAware(), etc.). This wouldn't be so bad
> > if it wasn't so expensive to create a DOMParser instance, but it is.
> > You should really be timing the parse and not the setup and parse.
> >
> > I was sort of shocked when I first discovered how poorly Xerces
> > handles setting JAXP DocumentBuilder properties, but from
> > conversations on this mailing list it's obviously a known problem and
> > there doesn't seem to be much that can be done about it. Shrug.
>
> Hello Curtis,
>
> What I didn't mention: I'm reusing the DocumentBuilder and this gives me
> only
> a small speedup. What I'm timing is the parsing itself, not the creation of
> the DocumentBuilder. Even if creating the DocumentBuilder was really slow,
> it
> wouldn't really be a problem because I'm using it in a Bean and it's only
> created once per Bean.
>
> Cheers, Jos
>
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