At first I used DocumentSource (a dom4j implementation) since
I already have the documents (dom4j documents)
cached and nothing worked regarding setting system id.
I then tried to use a simple StreamSource instead and then it
worked perfectly.
I guess there is a bug in dom4j or something then...
Unlike other interfaces, there is no guarantee that a particular XSLT
transformer will accept every class that implements Source as an input. Each
kind of Source requires specific code to handle it. Saxon doesn't recognize
dom4j's DocumentSource as one of the kinds of Source that it knows how to
handle. So, no bug.
(If anyone would like to implement the code needed to do this, based on the
current JDOM module, please feel free...)
Michael Kay