* Copyright (c) 2002-2018 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights * reserved. See for project information * https://simulation.tudelft.nl. The DSOL project is distributed under a three-clause BSD-style license, which can * be found at * https://simulation.tudelft.nl/dsol/3.0/license.html. *
* @author Alexander Verbraeck */ public abstract class AbstractXMLParser { /** schema validation on/off. */ private boolean validateSchema; /** the URL of the file to parse. */ private URL url; /** the URL of the schema file. */ private URL schema; /** the namespace of the schema. */ private String schemaNamespace; /** * Parses an XML file and validates it against a schema XSD. Explicitly call parse() from the extended class, after * other initialization tasks have been carried out. The parse() method will, after schema validation and xml-file * validation, call the parse(Element) method that has been declared in the extended class. * @param url URL; the URL of the XML file to read. * @param schema URL; the URL of the XSD schema file to validate against. * @param schemaNamespace String; the namespace of the schema * @param validateSchema boolean; whether to validate the schema file. */ public AbstractXMLParser(final URL url, final URL schema, final String schemaNamespace, final boolean validateSchema) { this.validateSchema = validateSchema; this.url = url; this.schema = schema; this.schemaNamespace = schemaNamespace; } /** * This method carries out the task of parsing an XML file and validates it against a schema XSD. dsol-xml now * contains the 2001 definitions of the schema files: XMLSchema.xsd, XMLSchema.dtd, xml.xsd, and datatypes.dtd to * validate against. When no network connection is available, these definitions can help for validation when *validation is true.
* @return the JDOM root element of the XML file
* @throws Exception on failure
*/
protected Element parse() throws Exception
{
if (this.validateSchema)
{
// create the parser to validate the schema file with SAX
XMLReader parser = XMLReaderFactory.createXMLReader("org.apache.xerces.parsers.SAXParser");
parser.setErrorHandler(new ValidHandler());
// turns on Schema Validation with Xerces
parser.setFeature("http://xml.org/sax/features/validation", true);
parser.setFeature("http://apache.org/xml/features/validation/schema", true);
// fatal error handler
parser.setEntityResolver(new RelativePathResolver());
parser.setErrorHandler(new ValidHandler());
parser.parse(this.schema.toExternalForm());
}
// build the DOM document for the content -- validation on
DOMParser domParser = new DOMParser();
domParser.setFeature("http://xml.org/sax/features/validation", true);
domParser.setFeature("http://apache.org/xml/features/validation/schema", true);
domParser.setProperty("http://apache.org/xml/properties/schema/external-schemaLocation",
this.schemaNamespace + " " + this.schema.toExternalForm());
domParser.setEntityResolver(new RelativePathResolver());
domParser.setErrorHandler(new ValidHandler());
// System.exit(0);
domParser.parse(this.url.toExternalForm());
Document document = domParser.getDocument();
DOMBuilder builder = new DOMBuilder();
org.jdom2.Document jdomDocument = builder.build(document);
Element xmlRootElement = jdomDocument.getRootElement();
return xmlRootElement;
}
/**
* The actual parsing method to implement, based on the availability of the entire JDOM tree, starting from the root
* element.
* @param xmlRootElement Element; the root element
* @throws Exception on failure
*/
protected abstract void parse(final Element xmlRootElement) throws Exception;
/**
* The ValidHandler ErrorHandler gives a more extensive explanation about errors that occur during parsing. If
* needed, this inner class can be overridden to provide other forms of error handling. * Copyright (c) 2003-2018 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights * reserved. See for project information * https://simulation.tudelft.nl. The DSOL project is distributed under a three-clause BSD-style license, which * can be found at * https://simulation.tudelft.nl/dsol/3.0/license.html. *
* @author Alexander Verbraeck */ private static class ValidHandler implements ErrorHandler { /** * format the exception with line number, column number, etc. * @param exception SAXParseException; the excpetion to format * @return the String */ private String formatError(final SAXParseException exception) { return "SAXParseException: \nsystemId=" + exception.getSystemId() + "\npublicId=" + exception.getSystemId() + "\nMessage=" + exception.getMessage() + "\nline,col=" + exception.getLineNumber() + "," + exception.getColumnNumber(); } /** {@inheritDoc} */ @Override public void warning(final SAXParseException exception) { // ignore, but log SimLogger.always().warn(exception, formatError(exception)); } /** {@inheritDoc} */ @Override public void error(final SAXParseException e) throws SAXException { throw new SAXException(formatError(e)); } /** {@inheritDoc} */ @Override public void fatalError(final SAXParseException e) throws SAXException { throw new SAXException(formatError(e)); } } /** * The relative path resolver takes care of resolving xsd-files or xml-files, that are in the current classpath. * Example use is theinclude tag in the schema file, that can now point to a relative path. * Copyright (c) 2003-2018 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights * reserved. See for project information * https://simulation.tudelft.nl. The DSOL project is distributed under a three-clause BSD-style license, which * can be found at * https://simulation.tudelft.nl/dsol/3.0/license.html. *
* @author Alexander Verbraeck */ private static class RelativePathResolver implements EntityResolver2 { /** the fallback defaultHandler2 */ private DefaultHandler2 defaultHandler2 = new DefaultHandler2(); /** {@inheritDoc} */ @Override public InputSource getExternalSubset(final String name, final String baseURI) throws SAXException, IOException { return this.defaultHandler2.getExternalSubset(name, baseURI); } /** {@inheritDoc} */ @Override public InputSource resolveEntity(final String name, final String publicId, final String baseURI, final String systemId) throws SAXException, IOException { return this.defaultHandler2.resolveEntity(name, publicId, baseURI, systemId); } /** {@inheritDoc} */ @Override public InputSource resolveEntity(final String publicId, final String systemId) throws SAXException, IOException { URL url; if (systemId.startsWith("file:")) { url = URLResource.getResource(systemId.substring(5)); } else { url = URLResource.getResource(systemId); } InputStream localStream = URLResource.getResourceAsStream(url.toExternalForm()); if (localStream != null) { return new InputSource(localStream); } return this.defaultHandler2.resolveEntity(publicId, systemId); } } }