Thanks for the suggestion. Not sure if that's going to work in my case though, how will I know which parser to use for which incoming document?
All documents come in through one entry point in a Servlet (so effectively multithreaded) Thanks Adam. -----Original Message----- From: Bill Michell [mailto:[EMAIL PROTECTED] Sent: 10 November 2008 12:03 To: j-users@xerces.apache.org Subject: RE: Problem validating using XMLGrammarPool with different Grammars with no namespace I hit this crazy bit of schema design myself. If you create one parser per schema document, you can give each one its own caching grammar pool, and re-use them from document to document. Of course, things are even more fun if you are parsing from multiple threads. It is possible to share the cached grammar pool (which is thread safe) amongst multiple parsers (which are not thread safe). My code is ugly, and can certainly be adjusted for your use case: /** * @param schemaLocation * @param preloadGrammars * @return a DOMParser for the specified schema * @throws IOException * @throws XNIException */ public static DOMParser domParserWithPrivateGrammarPool(final URL schemaLocation, final List<URL> preloadGrammars) throws XNIException, IOException { final XMLGrammarPool grammarPool = new XMLGrammarPoolImpl(); if (preloadGrammars!=null) { preloadGrammarsIntoPool(grammarPool,preloadGrammars); } final XMLGrammarCachingConfiguration config = new XMLGrammarCachingConfiguration( new SymbolTable(), grammarPool); config.setErrorHandler(new GenericXMLErrorHandler()); if (schemaLocation!=null) { config.setFeature(JAXP_VALIDATION_FEATURE, true); config.setFeature(JAXP_SCHEMA_VALIDATION_FEATURE, true); config.parseGrammar(XMLConstants.W3C_XML_SCHEMA_NS_URI, schemaLocation.toString()); } else { config.setFeature(JAXP_VALIDATION_FEATURE,false); } return new org.apache.xerces.parsers.DOMParser(config); } /** * @param grammarPool * @param preloadGrammars */ private static void preloadGrammarsIntoPool(final XMLGrammarPool grammarPool, final List<URL> preloadGrammars) { final XMLGrammarPreparser preparser=new XMLGrammarPreparser(); preparser.registerPreparser(XMLGrammarDescription.XML_DTD, null); preparser.registerPreparser(XMLGrammarDescription.XML_SCHEMA, null); preparser.setGrammarPool(grammarPool); for (final URL grammar:preloadGrammars) { if (logger.isInfoEnabled()) { logger.info("Preloading grammar for "+grammar.toExternalForm()); } try { final InputStream inputStream = new BufferedInputStream(grammar.openStream()); final XMLInputSource source=new XMLInputSource(null,grammar.toURI().getPath(),null,inputStream,null); if (grammar.getPath().endsWith(".dtd")) { preparser.preparseGrammar(XMLGrammarDescription.XML_DTD, source); } else { preparser.preparseGrammar(XMLGrammarDescription.XML_SCHEMA, source); } } catch (final IOException e) { // Preloading is just for convenience logger.warn("Error trying to preload grammar file "+grammar.toExternalForm(), e); } catch (final URISyntaxException e) { // Preloading is just for convenience logger.warn("Error trying to preload grammar file "+grammar.toExternalForm(), e); } } } -- Bill Michell Development Team Leader, Broadcast Platforms, BBC FM&T (Journalism). -----Original Message----- From: Adam Retter [mailto:[EMAIL PROTECTED] Sent: 10 November 2008 11:23 To: j-users@xerces.apache.org Subject: Problem validating using XMLGrammarPool with different Grammars with no namespace Hi Chaps, I am having some problems with XMLGrammarPool and I would like to confirm the cause of this. I think that it is because I have a number of different XML documents that use different XML Schemas, and these all use the same namespace i.e. no namespace. When I create a new XMLGrammarPool and validate document A with Schema 1 it works, however when I then validate document B with Schema 2 using the same XMLGrammarPool it fails as it cant find the Schema. Both document A and document B have no namespace defined. e.g. <a xsi:noNamespaceSchemaLocation="1.xsd" xmlns:xsi="xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";> ... </a> <b xsi:noNamespaceSchemaLocation="2.xsd" xmlns:xsi="xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";> ... </b> Our application needs to validate a number of different incoming XML documents using their XML Schemas, a number of these documents all have no namespace and use xsi:noNamespaceSchemaLocation="blah.xsd" to refer to their Schemas. I would like to use an XMLGrammarPool for caching Schemas to improve performance of the system. I thought that by implementing my own XMLGrammarPool I would be able to determine the uniqueness of an XMLSchema by something other than its namespace, e.g. its location. However this doesn't seem to be the case. After some investigation with the debugger: at line 1373 of XMLSchemaValidator in com.sun.org.apache.xerces.internal.impl.xs (Sun JDK 1.6.0_06) I see this comment in reset(XMLComponentManager componentManager) - // store the external schema locations. they are set when reset is called, // so any other schemaLocation declaration for the same namespace will be // effectively ignored. because we choose to take first location hint // available for a particular namespace. My question then is how and what do I need to do to get this working? Or if it is currently possible, then what am I doing wrong? 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