XOM API for Processing XML with Java

[Peter Murray-Rust <pm286 AT cam.ac.uk>]

Many thanks, this is very helpful

Tatu Saloranta wrote:
> Just to be clear, based on error message the problem is not the scheme part, 
> but that DTD references can not be located.

I guessed this might be the case. It's obviously a confusing error 
message but that may be inevitable if Xerces is involved. Just to 
confirm, the DTD itself is accessible - it is presumably references 
within it that give the problem.

> The usual work-around is to configure underlying parser (such as Xerces/SAX) 
> to redirect reads that are needed to access the DTD. For Sax this is done by 
> setting org.xml.sax.EntityResolver in XMLReader, and for Stax similarly by 
> setting XMLInputFactory.RESOLVER property on input factory. In either case, 
> one usually just returns empty document as dummy DTD.

Understood. However configuring Xerces is not always a relaxing 
operation and it would be nice to avoid it.

> DTD read is needed even when not validating since it could contain default attributes 
> or general entities. And although theoretically adding 'standalone="yes"' in 
> xml declaration might allow skipping reading, my recollection is that Xerces still 
> tries to read DTD in question no matter what.

Again I guessed this - I tried standalone="yes" without success and 
assumed some default overrid it.
> Hope this helps,
It does.

A gentle suggestion would be to be able to configure XOM to hide some of 
this. Basically "I know what I want to do and it uses simple XML ideas 
and doesn't need the complexity of DTDs, Schemas or whatever. I'll take 
my chances on in working as I would like". For many of us (as I have 
argued consistently since XML started) Xerces and XMLSchema are vastly 
more complex than we require and they cause us more problems than they 
solve. If it weren't for XOM I would have great problems in using XML.

P.

> -+ Tatu +-
>
>
> --- On Wed, 12/31/08, Peter Murray-Rust <pm286 AT cam.ac.uk> wrote:
>
> > From: Peter Murray-Rust <pm286 AT cam.ac.uk>
> > Subject: [XOM-interest] Problem with "Missing scheme in absolute URI 
> > reference"
> > To: xom-interest AT lists.ibiblio.org
> > Date: Wednesday, December 31, 2008, 9:32 AM
> > I am trying to parse some SVG generated by pstoedit and so
> > out of my 
> > control. This uses a DOCTYPE + remote DTD which appear to
> > be valid but 
> > which throw the above exception. (I don't understand it
> > as there are no 
> > explicit namespaceURIs). The SYSTEM identifiers appear to
> > be valid from 
> > the W3C site (I have copied them to make sure). I attach
> > (simplified) 
> > code snippets which demonstrate the problem using XOM-1.1.
> > The second 
> > one is valid against the W3C validation service (except for
> > missing 
> > required SVG attributes)
> >
> > At present the workaround is to edit the XML to remove the
> > DOCTYPE as I 
> > cannot control its output. I prefer not to do this - is
> > there a way of 
> > setting XOM to ignore the DOCTYPE or some otehr setting?
> >
> > Thanks
> >
> > P.
> >
> > public class TestXOM {
> >
> >    public static void main(String[] args) {
> >      String[] strings = {
> >          "<?xml version='1.0'
> > encoding='UTF-8'?>"+
> >          "<!DOCTYPE svg SYSTEM 
> > \"http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd\";>"+
> >          "<svg/>",
> >
> >          "<?xml version='1.0'
> > encoding='UTF-8'?>"+
> >          "<!DOCTYPE svg SYSTEM 
> > \"http://www.w3.org/TR/2000/03/WD-SVG-20000303/DTD/svg-20000303-stylable.dtd\";>"+
> >          "<svg/>",
> >
> >          "<?xml version='1.0'
> > encoding='UTF-8'?>"+
> >          "<!DOCTYPE svg SYSTEM 
> > \"http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/nonexistent.dtd\";>"+
> >          "<svg/>"
> >      };
> >      for (String s : strings) {
> >        try {
> >          new Builder().build(new StringReader(s));
> >          System.out.println("parsed OK");
> >        } catch (Exception e) {
> >          System.out.println(e);
> >        }
> >      }
> >    }
> > }
> >
> > which gives:
> >
> > parsed OK
> >
> > nu.xom.ParsingException: Missing scheme in absolute URI
> > reference
> >
> > java.io.FileNotFoundException: 
> > http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/nonexistent.dtd
> > _______________________________________________
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> > XOM-interest AT lists.ibiblio.org
> > http://lists.ibiblio.org/mailman/listinfo/xom-interest
>
>
>