Re: [xmlblaster] XML parser

[Peter Antman <pra at mint.se>]

On 17 Sep, Marcel Ruff wrote:
> pra at mint.se wrote:
> 
>>On 16 Sep, Till: xmlblaster at server.xmlBlaster.org wrote:
>>
>>Looking into my old code again a see that I have had to hardcode the
>>crimson parser into several classes. I really think this needs a
>>solution.
>>
>>>From my experience I would say this:
>>
>>1.   It does not help to do:
>>System.setProperty("javax.xml.parsers.DocumentBuilderFactory","org.apache.crimson.jaxp.DocumentBuilderFactoryImpl");
>>
>>System.setProperty("javax.xml.parsers.SAXParserFactory","org.apache.crimson.jaxp.SAXParserFactoryImpl");
>>
>>The spec (and xerces impl) is done in such a way that it is not possible
>>to bypass this in other classloader/locally. I cant belive the tricks in
>>SaxHandlerBase really works. I have tried that before without success.
>>
>>Or have I missed something? Why then is xerces loaded in my setup?
>>
> I believe it works, i think we have tested it.
> 
>>
>>2. The nonportable code is possible to write portable. I have portable
>>   code from other projects to do toString, merge and replace. But I
>>   think the portable code will be a lot slower (using XSL for
>>   serialization and the DOM api for the other).
>>
> It would be nice to have this option - if crimson is active the old code
> applies (probably by reflection to allow compiling), otherwise your 
> portable code
> is active. This way we never have a nogo, just a slower xmlBlaster.

I totaly agree, I will start the factory path tough. Testing is so
timeconsuming...

//Peter

 
>>
>>3. Since at least the string
>>   org.apache.crimson.jaxp.SAXParserFactoryImpl is hardcoded in several
>>   places (and it is actually today not possible to use XmlBlaster
>>   without crimson) I think we could as well hardcode crimson. Like this
>>   for example: SAXParserFactory spf = new
>>   org.apache.crimson.jaxp.SAXParserFactoryImpl();
>>
>>   It should probably even be done in a wrapper class: JAXPFactory,
>>   where we could get the SAXParserFactory, DocumentBuilderFactory and
>>   TransformerFactory. Here we could hardcode crimson or load
>>   dynamically.
>>
> Yes!
> 
>>
>>Any thoughts on this? It would be really nice to get a solution that
>>works in JBoss, even when xerces is the parser used.
>>
> Definitely yes, this problem arises from time to time again.
> 
> cu
> Marcel
> 
>>
>>//Peter
>>
>>  
>>
>>>Hi,
>>>may I be a little dogy.
>>>
>>>As far as I can see the XML parser loading in XmlBlaster is done in
>>>XmlProcessor where com.jclark.xsl.dom.SunXMLProcessorImpl(). It uses the
>>>com.sun.xml.parser.Parser to get at the parser. If I get it correct this
>>>however uses the JAXP API to get its real parser: i.e if this is set to
>>>xerces, or if xerces had the chance to load before crimson, xerces will
>>>be the parser used through SunXMLProcessorImpl. Since XmlBlaster uses
>>>crimson specific stuff to do important stuff this is not so good. I once
>>>wrote a helper for this:
>>>
>>>public class CrimsonProcessorImpl extends com.jclark.xsl.dom.XMLProcessorImpl  {
>>>
>>>    DocumentBuilderFactory dbf = null;
>>>    
>>>    public CrimsonProcessorImpl() {
>>>	dbf = new org.apache.crimson.jaxp.DocumentBuilderFactoryImpl();
>>>    }
>>>    
>>>    public org.w3c.dom.Document load(org.xml.sax.InputSource input)
>>>	throws java.io.IOException, org.xml.sax.SAXException {
>>>	DocumentBuilder db = null;
>>>	try {
>>>	    db = dbf.newDocumentBuilder ();
>>>	}catch(javax.xml.parsers.ParserConfigurationException ex) {
>>>	    throw new org.xml.sax.SAXException("Could not setup builder", ex);
>>>	}
>>>	return db.parse(input);
>>>
>>>    }
>>>	
>>>    public org.w3c.dom.Element getElementById(org.w3c.dom.Document doc, String str) {
>>>	return null;
>>>    }
>>>}
>>>
>>>And used that from XmlProcessor. But I guess mine is not as effective as
>>>yours. Any ideas on how to solve this would be great.
>>>
>>>//Peter
>>>    
>>>
>>
>>  
>>
> 

-- 
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Peter Antman	Chief Systems Architect, Business Development
Technology in Media, Box 34105 100 26 Stockholm
WWW: http://www.tim.se	WWW: http://www.backsource.org
Email: pra at tim.se	 
Phone: +46-(0)8-506 381 11 Mobile: 070-675 3942 
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