Java tutorial
/* * JBoss, Home of Professional Open Source * Copyright 2005, JBoss Inc., and individual contributors as indicated * by the @authors tag. See the copyright.txt in the distribution for a * full listing of individual contributors. * * This is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * This software is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */ package org.jbpm.jpdl.xml; import java.io.IOException; import java.io.Serializable; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.dom4j.Document; import org.dom4j.io.SAXReader; import org.xml.sax.EntityResolver; import org.xml.sax.ErrorHandler; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import org.xml.sax.SAXParseException; import org.xml.sax.XMLReader; /** * Validate an XML document using JAXP techniques and an XML Schema. This helper * class wraps the processing of a schema to aid in schema validation throughout * the product. * * @author Tom Baeyens * @author Jim Rigsbee */ public class JpdlParser implements Serializable { private static final long serialVersionUID = 1L; static final EntityResolver JPDL_ENTITY_RESOLVER = new JpdlEntityResolver(); static SAXParserFactory saxParserFactory = createSaxParserFactory(); public static Document parse(InputSource inputSource, ProblemListener problemListener) throws Exception { Document document = null; SAXReader saxReader = createSaxReader(problemListener); document = saxReader.read(inputSource); return document; } public static SAXReader createSaxReader(ProblemListener problemListener) throws Exception { XMLReader xmlReader = createXmlReader(); SAXReader saxReader = new SAXReader(xmlReader); saxReader.setErrorHandler(new JpdlErrorHandler(problemListener)); saxReader.setEntityResolver(JPDL_ENTITY_RESOLVER); return saxReader; } public static XMLReader createXmlReader() throws Exception { SAXParser saxParser = saxParserFactory.newSAXParser(); XMLReader xmlReader = saxParser.getXMLReader(); try { saxParser.setProperty("http://java.sun.com/xml/jaxp/properties/schemaLanguage", "http://www.w3.org/2001/XMLSchema"); } catch (SAXException e) { log.warn( "couldn't set xml parser property 'http://java.sun.com/xml/jaxp/properties/schemaLanguage' to 'http://www.w3.org/2001/XMLSchema'", e); } try { saxParser.setProperty("http://apache.org/xml/properties/schema/external-schemaLocation", "http://jbpm.org/3/jpdl http://jbpm.org/jpdl-3.0.xsd " + "urn:jbpm.org:jpdl-3.0 http://jbpm.org/jpdl-3.0.xsd " + "urn:jbpm.org:jpdl-3.1 http://jbpm.org/jpdl-3.1.xsd " + "urn:jbpm.org:jpdl-3.2 http://jbpm.org/jpdl-3.2.xsd"); } catch (SAXException e) { log.warn( "couldn't set xml parser property 'http://apache.org/xml/properties/schema/external-schemaLocation'", e); } try { xmlReader.setFeature("http://apache.org/xml/features/validation/dynamic", true); } catch (SAXException e) { log.warn("couldn't set xml parser feature 'http://apache.org/xml/features/validation/dynamic'", e); } return xmlReader; } static class JpdlErrorHandler implements ErrorHandler, Serializable { private static final long serialVersionUID = 1L; ProblemListener problemListener = null; JpdlErrorHandler(ProblemListener problemListener) { this.problemListener = problemListener; } public void warning(SAXParseException pe) { addProblem(Problem.LEVEL_WARNING, "line " + pe.getLineNumber() + ": " + pe.getMessage(), pe); } public void error(SAXParseException pe) { addProblem(Problem.LEVEL_ERROR, "line " + pe.getLineNumber() + ": " + pe.getMessage(), pe); } public void fatalError(SAXParseException pe) { addProblem(Problem.LEVEL_FATAL, "line " + pe.getLineNumber() + ": " + pe.getMessage(), pe); } void addProblem(int level, String description, Throwable exception) { problemListener.addProblem(new Problem(level, description, exception)); } } static class JpdlEntityResolver implements EntityResolver, Serializable { private static final long serialVersionUID = 1L; public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException { InputSource inputSource = null; log.debug("resolving schema reference publicId(" + publicId + ") systemId(" + systemId + ")"); if ("http://jbpm.org/jpdl-3.2.xsd".equals(systemId)) { log.debug("providing input source to local 'jpdl-3.2.xsd' resource"); inputSource = new InputSource(this.getClass().getResourceAsStream("jpdl-3.2.xsd")); } else if ("http://jbpm.org/jpdl-3.1.xsd".equals(systemId)) { log.debug("providing input source to local 'jpdl-3.1.xsd' resource"); inputSource = new InputSource(this.getClass().getResourceAsStream("jpdl-3.1.xsd")); } else if ("http://jbpm.org/jpdl-3.0.xsd".equals(systemId)) { log.debug("providing input source to local 'jpdl-3.0.xsd' resource"); inputSource = new InputSource(this.getClass().getResourceAsStream("jpdl-3.0.xsd")); } else { log.debug("original systemId as input source"); inputSource = new InputSource(systemId); } return inputSource; } } private static SAXParserFactory createSaxParserFactory() { SAXParserFactory saxParserFactory = SAXParserFactory.newInstance(); saxParserFactory.setValidating(true); saxParserFactory.setNamespaceAware(true); return saxParserFactory; } private static final Log log = LogFactory.getLog(JpdlParser.class); }