How to: JAXP, Xerces 2.6.2 and XML Schema ?

[joes]

Hello there

I tried for several days to get a simple validation with xml schema &
xerces working. Goal for me is tuse JAXP and not specific Xerces
classes. I don't get the point what I am doing wrong. Could somebody
help me? I didn't find any full example working on the net. Thank you
for any hints!

If I run the examples below, the parsers parses the file well, no
vlaidation is occuring although the schema and xml file does not
match.

I tried with the JAXP standard procedure, it does not work, why ?

File f = new File("dvd.xml");
SAXParserFactory saxFactory = SAXParserFactory.newInstance();
saxFactory.setNamespaceAware(true);
saxFactory.setValidating(true);
SAXParser saxParser = saxFactory.newSAXParser();
saxParser.parse(f, new DefaultHandler());

I tried with activating additional SAX Features, does also not work,
why ?

File f = new File("dvd.xml");
SAXParserFactory saxFactory = SAXParserFactory.newInstance();
saxFactory.setNamespaceAware(true);
saxFactory.setValidating(true);
saxFactory.setFeature("http://xml.org/sax/features/validation",true);
saxFactory.setFeature("http://apache.org/xml/features/validation/schema",true);
saxFactory.setFeature("http://apache.org/xml/features/validation/schema-full-checking",true);
SAXParser saxParser = saxFactory.newSAXParser();
saxParser.parse(f, new DefaultHandler());

Here is my xml:

<?xml version="1.0" encoding="utf-8" ?>
<dvd xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="dvd.xsd" id="33" available="3">Matrix
Revolutions</dvd>

Here is my xsd:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="dvdi" type="xs:string"/>
<xs:attribute name="id" type="xs:string"/>
<xs:attribute name="available" type="xs:boolean"/>
</xs:schema>

 

[Nigel Whitaker]

Hello there

I tried for several days to get a simple validation with xml schema &
xerces working. Goal for me is tuse JAXP and not specific Xerces
classes. I don't get the point what I am doing wrong. Could somebody
help me? I didn't find any full example working on the net. Thank you
for any hints!

Before you call SAXParserFactory.newInstance() you need to configure
the implementation lookup mechanism to use Xerces (the current JDK
1.4.x default is to use the Crimson parser).

One method (see the javadoc for the SAXParserFactory.newInstance()
method) would be to set a system property, from the command line using
-D, or in the code:

System.setProperty("javax.xml.parsers.SAXParserFactory",
"org.apache.xerces.jaxp.SAXParserFactoryImpl");

You need to do this in addition to having the xerces jar files in your classpath.

Nigel

 

[joes]

Thank you Nigel

But this is not the case. I do have already the xerces activated for
my application. By the way you have not to configure this by using
system properties. You can use the Jar service Provider Service
mechanism. Means you have just to include xerces in the class path
that's all.

I still not have a solution for my issue above, so has someone a
solution how to activate xml schema validation in xerces by using only
JAXP and not xerces specific classes ?

thank you
regards
mark

 

[joes]

Ok I found the solution by myself...
Please refer to:
http://xml.apache.org/~edwingo/jaxp-ri-1.2.0-fcs/docs/samples.html#Schema

After that I simple tried the following JAXP, SAX & DOM solutions
which work.
While this is not documented at the Xerces Homepage in detail, I don't
expect that this is working in any further releases, so be careful.

For SAX, you have to use especially the underlying xmlReader with the
saxparser interface from sun it is not working.

File f = new File("dvd.xml");
SAXParserFactory saxFactory = SAXParserFactory.newInstance();
saxFactory.setNamespaceAware(true);
saxFactory.setValidating(true);
saxFactory.setFeature("http://apache.org/xml/features/validation/schema",
true );
SAXParser saxParser = saxFactory.newSAXParser();
XMLReader xmlReader = saxParser.getXMLReader();
xmlReader.parse(f.getAbsolutePath());


A DOM solution would look and work like this:

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setAttribute("http://apache.org/xml/features/validation/schema",
Boolean.TRUE);
dbf.setNamespaceAware(true);
dbf.setValidating(true);
DocumentBuilder db = dbf.newDocumentBuilder();
db.parse(f);

don't give up...we are just at the beginning
regards
Mark Egloff

 

[Keith M. Corbett]

A DOM solution would look and work like this:

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setAttribute("http://apache.org/xml/features/validation/schema",
Boolean.TRUE);
dbf.setNamespaceAware(true);
dbf.setValidating(true);
DocumentBuilder db = dbf.newDocumentBuilder();
db.parse(f);

Sun's JAXP tutorial includes a more complete example along these lines. The
section "Reading XML Data into a DOM" illustrates necessary imports and
error handling. See URL:

http://java.sun.com/j2ee/1.4/docs/tutorial/doc/JAXPDOM3.html

Section "Validating with XML Schema" is at URL:

http://java.sun.com/j2ee/1.4/docs/tutorial/doc/JAXPDOM8.html#wp76446

/kmc