Java tutorial
/* * JBoss, Home of Professional Open Source. * Copyright 2008, Red Hat Middleware LLC, and individual contributors * as indicated by the @author tags. See the copyright.txt file 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.jboss.mx.metadata; // $Id: XMLMetaData.java 81026 2008-11-14 12:51:05Z dimitris@jboss.org $ import java.net.MalformedURLException; import java.net.URL; import java.util.Map; import javax.management.MBeanInfo; import javax.management.NotCompliantMBeanException; import org.dom4j.Document; import org.dom4j.DocumentException; import org.dom4j.DocumentType; import org.dom4j.Element; import org.dom4j.io.SAXReader; import org.jboss.mx.modelmbean.XMBeanConstants; import org.jboss.mx.service.ServiceConstants; import org.jboss.mx.util.JBossNotCompliantMBeanException; import org.jboss.util.xml.JBossEntityResolver; import org.xml.sax.SAXException; /** * Aggregate builder for XML schemas. This builder implementation is used * as an aggregate for all XML based builder implementations. The correct * XML parser is picked based on the schema declaration of the XML file. * * @author <a href="mailto:juha@jboss.org">Juha Lindfors</a>. * @author <a href="mailto:dimitris@jboss.org">Dimitris Andreadis</a>. * @author Matt Munz */ public class XMLMetaData extends AbstractBuilder implements ServiceConstants, XMBeanConstants { // Attributes ---------------------------------------------------- private static final int NO_VERSION = -1; private static final int JBOSS_XMBEAN_1_0 = 0; private static final int JBOSS_XMBEAN_1_1 = 1; private static final int JBOSS_XMBEAN_1_2 = 2; /** * The URL for the XML file. */ private URL url = null; private Element element; private String versionString; /** * The class name of the resource class this Model MBean represents. */ private String resourceClassName = null; /** * The class name of the Model MBean implementation class. */ private String mmbClassName = null; // Constructors -------------------------------------------------- /** * Constructs an aggregate XML builder implementation. * * @param mmbClassName the class name of the Model MBean * implementation * @param resourceClassName the class name of the resource object the * Model MBean represents * @param url the URL for the XML definition of the * management interface */ public XMLMetaData(String mmbClassName, String resourceClassName, URL url) { super(); this.url = url; this.mmbClassName = mmbClassName; this.resourceClassName = resourceClassName; } /** * Constructs an aggregate XML builder implementation. * * @param mmbClassName the class name of the Model MBean * implementation * @param resourceClassName the class name of the resource object the * Model MBean represents * @param url the URL for the XML definition of the * management interface * * @throws MalformedURLException if the URL string could not be resolved */ public XMLMetaData(String mmbClassName, String resourceClassName, String url) throws MalformedURLException { this(mmbClassName, resourceClassName, new URL(url)); } /** * Constructs an aggregate XML builder implementation. * * @param mmbClassName the class name of the Model MBean * implementation * @param resourceClassName the class name of the resource object the * Model MBean represents * @param url the URL for the XML definition of the * management interface * @param properties Map of configuration properties for this * builder. These properties will be passed * to the appropriate XML schema specific builder * when it is created. */ public XMLMetaData(String mmbClassName, String resourceClassName, URL url, Map properties) { this(mmbClassName, resourceClassName, url); setProperties(properties); } /** * Constructs an aggregate XML builder implementation. * * @param mmbClassName the class name of the Model MBean * implementation * @param resourceClassName the class name of the resource object the * Model MBean represents * @param url the URL for the XML definition of the * management interface * @param properties Map of configuration properties for this * builder. These properties will be passed * to the appropriate XML schema specific builder * when it is created. * * @throws MalformedURLException if the URL string could not be resolved */ public XMLMetaData(String mmbClassName, String resourceClassName, String url, Map properties) throws MalformedURLException { this(mmbClassName, resourceClassName, new URL(url), properties); } /** * Creates a new <code>XMLMetaData</code> instance using an explicit DOM element * as the configuration source, and requiring an explicit version indicator. * The version should be the PublicID for the dtd or (worse) the dtd url. * * @param mmbClassName a <code>String</code> value * @param resourceClassName a <code>String</code> value * @param element an <code>org.w3c.dom.Element</code> value * @param version a <code>String</code> value */ public XMLMetaData(String mmbClassName, String resourceClassName, Element element, String version) { super(); this.mmbClassName = mmbClassName; this.resourceClassName = resourceClassName; this.element = element; versionString = version; } // MetaDataBuilder implementation -------------------------------- /** * Constructs the Model MBean metadata. This implementation reads the * document type definition from the beginning of the XML file and picks * a corresponding XML builder based on the schema name. In case no * document type is defined the latest schema builder for this JBossMX * release is used. <p> * * The SAX parser implementation is selected by default based on JAXP * configuration. If you want to use JAXP to select the parser, you can * set the system property <tt>"javax.xml.parsers.SAXParserFactory"</tt>. * For example, to use Xerces you might define: <br><pre> * * java -Djavax.xml.parsers.SAXParserFactory=org.apache.xerces.jaxp.SAXParserFactoryImpl ... * * </pre> * * In case you can't or don't want to use JAXP to configure the SAX parser * implementation you can override the SAX parser implementation by setting * an MBean descriptor field {@link XMBeanConstants#SAX_PARSER} to the * parser class string value. * * @return initialized MBean info * @throws NotCompliantMBeanException if there were errors building the * MBean info from the given XML file. */ public MBeanInfo build() throws NotCompliantMBeanException { try { int version = NO_VERSION; if (versionString == null) { // by default, let JAXP pick the SAX parser SAXReader reader = new SAXReader(); // check if user wants to override the SAX parser property if (properties.get(SAX_PARSER) != null) { try { reader.setXMLReaderClassName(getStringProperty(SAX_PARSER)); } catch (SAXException e) { //Should log and ignore, I guess } // end of try-catch } // by default we validate reader.setValidation(true); // the user can override the validation by setting the VALIDATE property try { boolean validate = getBooleanProperty(XML_VALIDATION); reader.setValidation(validate); } catch (IllegalPropertyException e) { // FIXME: log the exception (warning) // fall through, use the default value } //supply it with our dtd locally. reader.setEntityResolver(new JBossEntityResolver()); // get the element and start parsing... Document doc = reader.read(url); element = doc.getRootElement(); DocumentType type = doc.getDocType(); version = validateVersionString(type.getPublicID()); if (version == NO_VERSION) { version = validateVersionString(type.getSystemID()); } // end of if () } else { version = validateVersionString(versionString); } // end of else if (element == null) { throw new IllegalStateException("No element supplied with explict version!"); } // These are the known schemas for us. Pick the correct one based on // schema or default to the latest.docURL.endsWith(JBOSSMX_XMBEAN_DTD_1_0) if (version == JBOSS_XMBEAN_1_0 || version == JBOSS_XMBEAN_1_1 || version == JBOSS_XMBEAN_1_2) { // jboss_xmbean_1_0.dtd is the only implemented useful xmbean return new JBossXMBean10(mmbClassName, resourceClassName, element, properties).build(); } else { throw new NotCompliantMBeanException("Unknown xmbean type " + versionString); } // end of else } catch (DocumentException e) { throw new JBossNotCompliantMBeanException("Error parsing the XML file, from XMLMetaData: ", e); } } private int validateVersionString(String versionString) { if (PUBLIC_JBOSSMX_XMBEAN_DTD_1_0.equals(versionString)) { return JBOSS_XMBEAN_1_0; } // end of if () if (versionString != null && versionString.endsWith(JBOSSMX_XMBEAN_DTD_1_0)) { return JBOSS_XMBEAN_1_0; } // end of if () if (PUBLIC_JBOSSMX_XMBEAN_DTD_1_1.equals(versionString)) { return JBOSS_XMBEAN_1_1; } // end of if () if (versionString != null && versionString.endsWith(JBOSSMX_XMBEAN_DTD_1_1)) { return JBOSS_XMBEAN_1_1; } // end of if () if (PUBLIC_JBOSSMX_XMBEAN_DTD_1_2.equals(versionString)) { return JBOSS_XMBEAN_1_2; } // end of if () if (versionString != null && versionString.endsWith(JBOSSMX_XMBEAN_DTD_1_2)) { return JBOSS_XMBEAN_1_2; } // end of if () //There is nothing defined for jboss xmbean 1.2, so we can't recognize it. return NO_VERSION; } }