Schema validation routine?

Question

Hi
I have serious problems finding a (PL/SQL) validation routine that takes a piece of xml and a corresponding schema and validates the xml according to the schema. Everything (PL/SQL) seems to demand that I register my schema and define columns on that schema, and that's a problem with my application (basically, I have a "free format" xmltype column to which a schema is attached - the user may define both the xml and the schema)
I need a PL/SQL function basically like "oraxml -schema".
Can anyone help me out here, or do I need to write a Java-function to do the trick?
Regards
/John

Answer 1

you can pass a CLOB as a parameter by using a slightly adapted version of the example code:
package ibb.xml;
import java.net.*;
import java.io.*;
import java.util.*;
import java.sql.SQLException;
import oracle.sql.CLOB;
import oracle.xml.parser.schema.*;
import oracle.xml.parser.v2.*;
import org.w3c.dom.*;
public class XMLSchemaUtils
public static String validate(CLOB xmlDoc, CLOB xsdDoc)
throws Exception
//Build Schema Object
XSDBuilder builder = new XSDBuilder();
InputStream xsdInAsciiFormat = xsdDoc.getAsciiStream();
XMLSchema schemadoc = (XMLSchema)builder.build(xsdInAsciiFormat, null);
//Build XML Object
InputStream xmlInAsciiFormat = xmlDoc.getAsciiStream();
// Greate the DOM
DOMParser domparser_doc = new DOMParser();
// Set Schema Object for Validation
domparser_doc.setXMLSchema(schemadoc);
domparser_doc.setValidationMode(XMLParser.SCHEMA_VALIDATION);
domparser_doc.setPreserveWhitespace (true);
// New stream for the return string
StringWriter string_writer_stream = new StringWriter();
domparser_doc.setErrorStream (new PrintWriter(string_writer_stream));
String returnValue;
try {
domparser_doc.parse (xmlInAsciiFormat);
returnValue = "The input XML parsed without errors.\n";
catch (XMLParseException pe) {
returnValue = "Parser Exception: " + pe.getMessage();
catch (Exception e) {
returnValue = "NonParserException: " + e.getMessage();
return returnValue;
I don't (yet) understand the suggestion by Deepak to set an ErrorHandler on the DOMParser. This is possible as you can use setErrorHandler(handler) on any object inherited from parser (that is both for the DOMParser and the SAXParser) like:
ErrorHandler handler = new ErrorHandler();
domparser_doc.setErrorHandler(handler);
But according to the documentation the ErrorHandler is only used by the SAXParser.
At the moment this advanced Java stuff is too complex for a simple PL/SQL programmer like me... Deepak! Help!