Java tutorial
/* * File : $Source: /alkacon/cvs/alkacon/com.alkacon.opencms.feeder/src/com/alkacon/opencms/feeder/CmsFeedXmlContentHandler.java,v $ * Date : $Date: 2007/12/13 15:48:47 $ * Version: $Revision: 1.1 $ * * This file is part of the Alkacon OpenCms Add-On Module Package * * Copyright (c) 2007 Alkacon Software GmbH (http://www.alkacon.com) * * The Alkacon OpenCms Add-On Module Package is free software: * you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * The Alkacon OpenCms Add-On Module Package 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with the Alkacon OpenCms Add-On Module Package. * If not, see http://www.gnu.org/licenses/. * * For further information about Alkacon Software GmbH, please see the * company website: http://www.alkacon.com. * * For further information about OpenCms, please see the * project website: http://www.opencms.org. */ package com.alkacon.opencms.feeder; import org.opencms.configuration.CmsConfigurationManager; import org.opencms.i18n.CmsEncoder; import org.opencms.main.CmsRuntimeException; import org.opencms.util.CmsFileUtil; import org.opencms.xml.CmsXmlContentDefinition; import org.opencms.xml.CmsXmlEntityResolver; import org.opencms.xml.CmsXmlException; import org.opencms.xml.CmsXmlUtils; import org.opencms.xml.content.CmsDefaultXmlContentHandler; import org.opencms.xml.content.Messages; import org.opencms.xml.types.I_CmsXmlSchemaType; import java.util.Collections; import java.util.Iterator; import org.dom4j.Document; import org.dom4j.DocumentHelper; import org.dom4j.Element; /** * Adds syndication feed mapping rules to the default XML content handler.<p> * * @author Alexander Kandzior * * @version $Revision: 1.1 $ */ public class CmsFeedXmlContentHandler extends CmsDefaultXmlContentHandler { /** Constant for the "feedrule" element name. */ public static final String APPINFO_FEEDRULE = "feedrule"; /** Constant for the "feedrules" element name. */ public static final String APPINFO_FEEDRULES = "feedrules"; /** Constant for the "default" attribute. */ public static final String ATTR_DEFAULT = "default"; /** Constant for the "maxLength" attribute. */ public static final String ATTR_MAXLENGTH = "maxLength"; /** The path to the Alkacon OpenCms Feeder package (calculated from the package name). */ public static final String FEED_PACKAGE_PATH = CmsFeed.class.getPackage().getName().replace('.', '/'); /** The file where the extended feed schema is located. */ public static final String FEED_APPINFO_SCHEMA_FILE = FEED_PACKAGE_PATH + "/FeedAppinfo.xsd"; /** The XML system id for the extended feed schema. */ public static final String FEED_APPINFO_SCHEMA_SYSTEM_ID = CmsConfigurationManager.DEFAULT_DTD_PREFIX + FEED_APPINFO_SCHEMA_FILE; /** The feed mapping this class is all about. */ protected CmsFeedContentMapping m_feedMapping; /** * Static initializer for caching the extended feed validation schema.<p> */ static { // the schema definition is located in a separate file for easier editing byte[] appinfoSchema; try { appinfoSchema = CmsFileUtil.readFile(FEED_APPINFO_SCHEMA_FILE); } catch (Exception e) { throw new CmsRuntimeException(Messages.get().container( org.opencms.xml.types.Messages.ERR_XMLCONTENT_LOAD_SCHEMA_1, FEED_APPINFO_SCHEMA_FILE), e); } CmsXmlEntityResolver.cacheSystemId(FEED_APPINFO_SCHEMA_SYSTEM_ID, appinfoSchema); } /** * Returns the initialized feed mapping for this XML content handler.<p> * * @return the initialized feed mapping for this XML content handler */ public CmsFeedContentMapping getFeedMapping() { return m_feedMapping; } /** * @see org.opencms.xml.content.CmsDefaultXmlContentHandler#initialize(org.dom4j.Element, org.opencms.xml.CmsXmlContentDefinition) */ public synchronized void initialize(Element appInfoElement, CmsXmlContentDefinition contentDefinition) throws CmsXmlException { if (appInfoElement != null) { // first initialize all the default values super.initialize(appInfoElement, contentDefinition); Element feedElement = appInfoElement.element(APPINFO_FEEDRULES); if (feedElement != null) { initFeedRules(feedElement, contentDefinition); } } } /** * Adds a feed rule mapping.<p> * * @param contentDefinition the XML content definition this XML content handler belongs to * @param xmlField the element name to map to the feed * @param feedField the feed field to map the XML field to * @param maxLength the optional max length of the field * @param defaultValue the optional default value for the mapping * * @throws CmsXmlException in case an unknown element name is used */ protected void addFeedRule(CmsXmlContentDefinition contentDefinition, String xmlField, String feedField, String maxLength, String defaultValue) throws CmsXmlException { if (contentDefinition.getSchemaType(xmlField) == null) { throw new CmsXmlException( Messages.get().container(Messages.ERR_XMLCONTENT_INVALID_ELEM_MAPPING_1, xmlField)); } m_feedMapping.addFeedFieldMapping(Collections.singletonList(CmsXmlUtils.createXpath(xmlField, 1)), feedField, maxLength, defaultValue); } /** * @see org.opencms.xml.content.CmsDefaultXmlContentHandler#init() */ protected void init() { super.init(); m_feedMapping = new CmsFeedContentMapping(); } /** * Initializes the feed rule mappings for this content handler.<p> * * @param root the "feedrules" element from the appinfo node of the XML content definition * @param contentDefinition the content definition the mappings belong to * * @throws CmsXmlException if something goes wrong */ protected void initFeedRules(Element root, CmsXmlContentDefinition contentDefinition) throws CmsXmlException { Iterator i = root.elementIterator(APPINFO_FEEDRULE); while (i.hasNext()) { // iterate all "mapping" elements in the "mappings" node Element element = (Element) i.next(); // this is a mapping node String xmlField = element.attributeValue(APPINFO_ATTR_ELEMENT); String maptoName = element.attributeValue(APPINFO_ATTR_MAPTO); String maxLength = element.attributeValue(ATTR_MAXLENGTH); String defaultValue = element.attributeValue(ATTR_DEFAULT); if ((xmlField != null) && (maptoName != null)) { // add the element mapping addFeedRule(contentDefinition, xmlField, maptoName, maxLength, defaultValue); } } } /** * @see org.opencms.xml.content.CmsDefaultXmlContentHandler#validateAppinfoElement(org.dom4j.Element) */ protected void validateAppinfoElement(Element appinfoElement) throws CmsXmlException { // create a document to validate Document doc = DocumentHelper.createDocument(); Element root = doc.addElement(APPINFO_APPINFO); // attach the default appinfo schema root.add(I_CmsXmlSchemaType.XSI_NAMESPACE); root.addAttribute(I_CmsXmlSchemaType.XSI_NAMESPACE_ATTRIBUTE_NO_SCHEMA_LOCATION, FEED_APPINFO_SCHEMA_SYSTEM_ID); // append the content from the appinfo node in the content definition root.appendContent(appinfoElement); // now validate the document with the default appinfo schema CmsXmlUtils.validateXmlStructure(doc, CmsEncoder.ENCODING_UTF_8, new CmsXmlEntityResolver(null)); } }