XOM API for Processing XML with Java

["Nick Day" <the_doctor_nick AT hotmail.com>]

Hi,

Many thanks for the advice!

I am now using TagSoup to parse HTML documents, however I have run into a 
problem when attempting to query the resulting Documents using XPath.  I 
have set up a test method (bottom) which reads in a HTML page from a 
specified URL and then queries it using XPath.  The matching elements are 
then printed out.

If, for example I use 
http://wwmm.ch.cam.ac.uk/data/kegg/cml_inchi/C12384.cml and query it using 
//* I get the following printout:

NUMBER OF MATCHING ELEMENTS: 100
Element number: 0 [nu.xom.Element: html]
Element number: 1 [nu.xom.Element: body]
.... more element declarations
Element number: 99 [nu.xom.Element: bond]
FINISH

But if I try to match against any element in particular (e.g. using //body) 
then the result I get is:

NUMBER OF MATCHING ELEMENTS: 0
FINISH

So the individual elements are being recognised, but I can't seem to 
retrieve them using the query method.  Does anyone else have any experience 
with this?

many thanks,
Nick

public static void main(String[] args) {
                Document doc = null;
                try {
			XMLReader tagsoup = 
XMLReaderFactory.createXMLReader("org.ccil.cowan.tagsoup.Parser");
                        Builder builder = new Builder(tagsoup);
		    doc = 
builder.build("http://wwmm.ch.cam.ac.uk/data/kegg/cml_inchi/C12384.cml";);
                } catch (SAXException e) {
                        e.printStackTrace();
                } catch (ValidityException e) {
                        e.printStackTrace();
                } catch (ParsingException e) {
                        e.printStackTrace();
                } catch (IOException e) {
                        e.printStackTrace();
                }

                String xpath = "//*";
                Nodes elements = doc.query(xpath);
                System.out.println("NUMBER OF MATCHING ELEMENTS: " + 
elements.size());
                for (int i = 0; i < elements.size(); i++) {
			System.out.println("Element number: " + i + " " + 
elements.get(i).toString());
                }
                System.out.println("FINISH");
        }

-------------------------------------------------------------------------------------------------------------------------------------------






> From: Wolfgang Hoschek <wolfgang.hoschek AT mac.com>
> To: Nick Day <the_doctor_nick AT hotmail.com>
> CC: xom-interest AT lists.ibiblio.org
> Subject: Re: [XOM-interest] Problem parsing HTML file into Document
> Date: Sat, 10 Dec 2005 17:55:00 -0800
>
> HTML is not wellformed XML, so you need to preprocess it with  something 
> like TagSoup.
> Tagsoup makes HTML appear as if it were XML. See http:// 
> mercury.ccil.org/~cowan/XML/tagsoup/
>
> Wolfgang.
>
> On Dec 10, 2005, at 3:09 PM, Nick Day wrote:
>
> > Hi,
> >
> > I've been having a bit of trouble parsing a HTML file (attached)  into a 
> > document and keep getting the error below.  Do I need to  preprocess the 
> > file into a different encoding before attempting the  creation of the 
> > Document object or am I way off?
> >
> > thanks,
> > Nick
> >
> > nu.xom.ParsingException: Invalid byte 1 of 1-byte UTF-8 sequence.  in 
> > file:/f:/test.txt
> >     at nu.xom.Builder.build(Builder.java:1157)
> >     at nu.xom.Builder.build(Builder.java:614)
> >     at nu.xom.Builder.build(Builder.java:990)
> >     at  uk.ac.cam.ch.wwmm.scuflworkers.java.StripElementsFromXMLTest.main 
> > (StripElementsFromXMLTest.java:23)
> > Caused by: java.io.UTFDataFormatException: Invalid byte 1 of 1-byte  UTF-8 
> > sequence.
> >     at org.apache.xerces.impl.io.UTF8Reader.invalidByte(Unknown  Source)
> >     at org.apache.xerces.impl.io.UTF8Reader.read(Unknown Source)
> >     at org.apache.xerces.impl.XMLEntityScanner.load(Unknown Source)
> >     at org.apache.xerces.impl.XMLEntityScanner.scanLiteral(Unknown  
> > Source)
> >     at org.apache.xerces.impl.XMLScanner.scanAttributeValue(Unknown  
> > Source)
> >     at  
> > org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanAttribute 
> > (Unknown Source)
> >     at  
> > org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement 
> > (Unknown Source)
> >     at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl 
> > $FragmentContentDispatcher.dispatch(Unknown Source)
> >     at  
> > org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument 
> > (Unknown Source)
> >     at org.apache.xerces.parsers.DTDConfiguration.parse(Unknown  Source)
> >     at org.apache.xerces.parsers.DTDConfiguration.parse(Unknown  Source)
> >     at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
> >     at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown  Source)
> >     at nu.xom.Builder.build(Builder.java:1127)
> >     ... 3 more
> > Exception in thread "main" java.lang.NullPointerException
> >     at  uk.ac.cam.ch.wwmm.scuflworkers.java.StripElementsFromXml.strip 
> > (StripElementsFromXml.java:22)
> >     at  uk.ac.cam.ch.wwmm.scuflworkers.java.StripElementsFromXMLTest.main 
> > (StripElementsFromXMLTest.java:34)
> >
> >
> > <test.txt>
> > _______________________________________________
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