Validating XML: specifying schema externally

["Mayne, Peter" <PeterMayne@ap.spherion.com>]

I'm trying to use org.apache.xerces.parsers.SAXParser from Java to validate
an XML document.

If the document starts:

<?xml version="1.0"?>
<PurchaseOrder
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
            xsi:noNamespaceSchemaLocation="PO.xsd"
>
<Header>...</Header>
...

then the code below does the right thing (assuming that PO.xsd is present),
such that if I change <Header></Header> to <xHeader></xHeader>, the document
won't validate.

However, the incoming documents do not have the namespace declarations in
them, so I'm attempting to validate them by specifying the schema from Java.
However, this isn't working properly: the document will be parsed without
errors, even if it contains <xHeader></xHeader>.

What do I have to do to force the document to be validated against a schema
that I specify?

Thanks.

Partial code:

    static final String DEFAULT_PARSER_NAME =
"org.apache.xerces.parsers.SAXParser";
    
    static final String VALIDATION_FEATURE =
"http://xml.org/sax/features/validation";;
    static final String SCHEMA_VALIDATION_FEATURE =
"http://apache.org/xml/features/validation/schema";;
    static final String DYNAMIC_VALIDATION_FEATURE =
"http://apache.org/xml/features/validation/dynamic";;
    static final String SCHEMA_NO_NAMESPACE_LOCATION_PROPERTY =
"http://apache.org/xml/properties/schema/external-noNamespaceSchemaLocation";
;
    static final String SCHEMA_LOCATION_PROPERTY =
"http://apache.org/xml/properties/schema/external-schemaLocation";;
    static final String SCHEMA_FULL_CHECKING_FEATURE =
"http://apache.org/xml/features/validation/schema-full-checking";;

    public static void main(String[] args)
    {
       if(args.length != 1)
        {
            System.err.println("Usage: java ParseXML <filename>");
            System.exit(1);
        }
        
        XMLReader parser = null;
        try
        {
            parser = XMLReaderFactory.createXMLReader(DEFAULT_PARSER_NAME);
        }
        catch (Exception e)
        {
            System.err.println("error: Unable to instantiate parser (" +
DEFAULT_PARSER_NAME + ")");
            System.exit(1);
        }

        try
        {
            // try various features/properties
            parser.setFeature(VALIDATION_FEATURE, true);
            parser.setFeature(SCHEMA_VALIDATION_FEATURE, true);
            //parser.setFeature(SCHEMA_FULL_CHECKING_FEATURE, true);
            parser.setFeature(DYNAMIC_VALIDATION_FEATURE, true);
            //parser.setProperty(SCHEMA_NO_NAMESPACE_LOCATION_PROPERTY,
"file:///c:/home/code/eclipsetest/test/telstraPO.xsd");
            parser.setProperty(SCHEMA_NO_NAMESPACE_LOCATION_PROPERTY,
"PO.xsd");
            //parser.setProperty(SCHEMA_LOCATION_PROPERTY,
"file:///c:/home/code/eclipsetest/test/telstraPO.xsd
file:///c:/home/code/eclipsetest/test/PO.xsd");
            //parser.setProperty(SCHEMA_LOCATION_PROPERTY,
"http://www.w3.org/2001/XMLSchema-instance
file:///c:/home/code/eclipsetest/test/PO.xsd");
            parser.setErrorHandler(new ErrorHandler()
            {
                public void fatalError(SAXParseException spe)
                    throws SAXException
                {
                    printError("Fatal Error", spe);
                }
                public void error(SAXParseException spe)
                    throws SAXParseException
                {
                    printError("Error", spe);
                    System.out.println("error");
                }
                public void warning(SAXParseException spe)
                    throws SAXParseException
                {
                    printError("Warning", spe);
                }
            });
            if(false) // not using this at the moment
            {
                parser.setEntityResolver(new EntityResolver()
                {
                    public InputSource resolveEntity (String publicId,
String systemId)
                    {
                        System.out.println("publicId[" + publicId + "]");
                        System.out.println("systemId[" + systemId + "]");
                        return new InputSource();
                    }
                });
            }
        }
        catch(SAXNotRecognizedException e)
        {
            System.err.println("not recognised: " + e);
            System.exit(1);
        }
        catch(SAXNotSupportedException snse)
        {
            System.err.println("not supported: " + snse);
            System.exit(1);
        }
        
        try
        {
            System.out.println("begin parsing");
            parser.parse(args[0]);
            System.out.println("end parsing");
        }
        catch(Exception e)
        {
            System.err.println("Parsing error: " + e);
            e.printStackTrace();
        }

PJDM
-- 
Peter Mayne
Technology Consultant
Spherion Technology Solutions
Level 1, 243 Northbourne Avenue, Lyneham, ACT, 2602
T: 61 2 62689727  F: 61 2 62689777
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