RE: dom build speed

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:jvdoever@xxxxxxxxx] 
Sent: Monday, February 14, 2005 6:56 AM
To: xerces-j-user@xxxxxxxxxxxxxx
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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