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Posted to users@tomcat.apache.org by Gil Hauer <gi...@technolog.ca> on 2003/04/30 19:37:59 UTC

building a DOM from with a JSP page

Hello,

I'm trying to read an XML file and build a DOM from within a JSP page. I
have the code working as a standalone java application. After parsing
the XML file I print out the Document object and get this result:

  document = org.apache.crimson.tree.XmlDocument@f9f9d8

When I put this same (well, the body is identical) code in a JSP page I
get this result:


  document = [#document: null]

I've taken the code from Sun's XML tutorial (included below).

Has anyone experienced this behaviour? At first I thought that the file
was not being read so I changed the filename to one that is invalid and
got a Java stacktrace (as expected); this means that it's actually
readin the file.

I don't think I'm getting any exceptions since I 'catch' the following:

   SAXParseException 
   SAXException 
   ParserConfigurationException 
   IOException

Finally, here's the code:

    Document document;

    DocumentBuilderFactory factory =
        DocumentBuilderFactory.newInstance();
    //factory.setValidating(true);   
    //factory.setNamespaceAware(true);
    try {
	DocumentBuilder builder = factory.newDocumentBuilder();
	document = builder.parse(topics_filename);
	System.err.println("document = " + document);
    } catch (SAXParseException spe) {
	// Error generated by the parser
	System.out.println("\n** Parsing error"
			   + ", line " + spe.getLineNumber()
			   + ", uri " + spe.getSystemId());
	System.out.println("   " + spe.getMessage() );

	// Use the contained exception, if any
	Exception  x = spe;
	if (spe.getException() != null) {
	    x = spe.getException();
	}
	x.printStackTrace();
 
    } catch (SAXException sxe) {
	// Error generated during parsing)
	Exception  x = sxe;
	if (sxe.getException() != null)
	    x = sxe.getException();
	x.printStackTrace();
	
    } catch (ParserConfigurationException pce) {
	// Parser with specified options can't be built
	pce.printStackTrace();

    } catch (IOException ioe) {
	// I/O error
	ioe.printStackTrace();
    }






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SOLVED: Re: building a DOM from with a JSP page

Posted by Gil Hauer <gi...@technolog.ca>.
Well, it turns out the 'document' is not really null; I can get at the
nodes with getElementByTagName. The 'null' text in the printout is
simple there to confuse :)

Thanks,
Gil

On Wed, 2003-04-30 at 13:37, Gil Hauer wrote:
> Hello,
> 
> I'm trying to read an XML file and build a DOM from within a JSP page. I
> have the code working as a standalone java application. After parsing
> the XML file I print out the Document object and get this result:
> 
>   document = org.apache.crimson.tree.XmlDocument@f9f9d8
> 
> When I put this same (well, the body is identical) code in a JSP page I
> get this result:
> 
> 
>   document = [#document: null]
> 
> I've taken the code from Sun's XML tutorial (included below).
> 
> Has anyone experienced this behaviour? At first I thought that the file
> was not being read so I changed the filename to one that is invalid and
> got a Java stacktrace (as expected); this means that it's actually
> readin the file.
> 
> I don't think I'm getting any exceptions since I 'catch' the following:
> 
>    SAXParseException 
>    SAXException 
>    ParserConfigurationException 
>    IOException
> 
> Finally, here's the code:
> 
>     Document document;
> 
>     DocumentBuilderFactory factory =
>         DocumentBuilderFactory.newInstance();
>     //factory.setValidating(true);   
>     //factory.setNamespaceAware(true);
>     try {
> 	DocumentBuilder builder = factory.newDocumentBuilder();
> 	document = builder.parse(topics_filename);
> 	System.err.println("document = " + document);
>     } catch (SAXParseException spe) {
> 	// Error generated by the parser
> 	System.out.println("\n** Parsing error"
> 			   + ", line " + spe.getLineNumber()
> 			   + ", uri " + spe.getSystemId());
> 	System.out.println("   " + spe.getMessage() );
> 
> 	// Use the contained exception, if any
> 	Exception  x = spe;
> 	if (spe.getException() != null) {
> 	    x = spe.getException();
> 	}
> 	x.printStackTrace();
>  
>     } catch (SAXException sxe) {
> 	// Error generated during parsing)
> 	Exception  x = sxe;
> 	if (sxe.getException() != null)
> 	    x = sxe.getException();
> 	x.printStackTrace();
> 	
>     } catch (ParserConfigurationException pce) {
> 	// Parser with specified options can't be built
> 	pce.printStackTrace();
> 
>     } catch (IOException ioe) {
> 	// I/O error
> 	ioe.printStackTrace();
>     }
> 
> 
> 
> 
> 
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> 


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