Re: [xsl] Running transformations using JSTL

[Roger <rxt360@xxxxxxxxx>]

Hi Michael,

I've been using this for about two years. I can send you a simple setup 
(via an attachment) if you're interested.

Roger

Michael Kay schreef:
> Does anyone have experience of running transformations using the JSP
> Standard Tag Library?
>
> I have a user who is attempting it, and is seeing symptoms that suggest that
> the same Transformer is being used in more than one thread. This is
> consistent with the JSTL spec, which says in section 13.1: 
>
> "A more efficient approach is to process the transformation stylesheet once,
> and then save this "transformer" object for successive transformations. The
> specification allows implementations to support
> transparent caching of transformer objects to improve performance."
>
> But the JAXP Transformer is not reusable in this way. The Javadoc for
> javax.xml.transform.Transformer says "An object of this class may not be
> used in multiple threads running concurrently. Different Transformers may be
> used concurrently by different threads." 
>
> The object that should be cached is the Templates object, not the
> Transformer.
>
> Is it possible that jstl has got this wrong? It would seem a surprisingly
> grave blunder. Perhaps in the Xalan implementation the Transformer object
> can be safely reused across threads, despite the JAXP specification saying
> it can't?
>
> Any insights welcome.
>
> Michael Kay
> http://www.saxonica.com/