What is default value of the javax.xml.transform.Transformer sys property?

Question

Hi all
In my other thread "javax.xml.transform." last replied to on 17/04/05, I described that having & in my xml was causing TransformerExceptions when I attempted to apply a stylesheet to the xml.
I've now deployed exactly the same xml, xsl and java on a completely different environment and have found that the error does NOT occur.
This completely baffled me at first, but then I read the following in the API documentation for TransformerFactory: -
"A TransformerFactory instance can be used to create Transformer and Templates objects.
The system property that determines which Factory implementation to create is named "javax.xml.transform.TransformerFactory". This property names a concrete subclass of the TransformerFactory abstract class. If the property is not defined, a platform default is be used.
I think that the key must lie in the system property "javax.xml.transform.TransformerFactory". The two environments must be using a different value for this - one representing a class that objects to & and one that doesn't. In neither case do I actually set this property, so my main question is what does it default to and how can I find out what each environment is using for this?
I'm really baffled here guys, any help would be massively appreciated.
Thank you
Jon

Answer 1

javax.xml.transform.TransformerFactory is a real class implemented by someone. It looks at the system property to figure out what actual implementation to use. It the property doesn't exist, it uses the class that came bundled with the javax.xml.transform.TransformerFactory class you are using.
Here, for instance, is the javax.xml.transform.TransformerFactory that comes with jdk1.4.2
    public static TransformerFactory newInstance()
        throws TransformerFactoryConfigurationError
        try {
            return (TransformerFactory) FactoryFinder.find(
                /* The default property name according to the JAXP spec */
                "javax.xml.transform.TransformerFactory",
                /* The fallback implementation class name */
                "org.apache.xalan.processor.TransformerFactoryImpl");
        } catch (FactoryFinder.ConfigurationError e) {
            throw new TransformerFactoryConfigurationError(e.getException(),
                                                           e.getMessage());
    }