/* * XSLTCrosswalk.java * * Version: $Revision: 1.1 $ * * Date: $Date: 2006/03/17 00:04:38 $ * * Copyright (c) 2002-2005, Hewlett-Packard Company and Massachusetts * Institute of Technology. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of the Hewlett-Packard Company nor the name of the * Massachusetts Institute of Technology nor the names of their * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH * DAMAGE. */ package org.dspace.content.crosswalk; import java.io.InputStream; import java.io.IOException; import java.sql.SQLException; import java.util.Iterator; import java.util.List; import java.util.ArrayList; import java.util.HashMap; import java.util.Properties; import java.util.Enumeration; import java.io.OutputStream; import java.io.StringReader; import java.io.File; import java.io.FileInputStream; import java.sql.SQLException; import org.apache.log4j.Logger; import org.dspace.core.Context; import org.dspace.core.Constants; import org.dspace.content.Item; import org.dspace.content.DCDate; import org.dspace.content.DCValue; import org.dspace.content.DSpaceObject; import org.dspace.authorize.AuthorizeException; import org.dspace.core.ConfigurationManager; import org.dspace.core.SelfNamedPlugin; import org.jdom.*; import org.jdom.output.XMLOutputter; import org.jdom.output.Format; import org.jdom.input.SAXBuilder; import org.jdom.input.JDOMParseException; import org.jdom.xpath.XPath; import org.jdom.transform.XSLTransformer; import org.jdom.transform.XSLTransformException; /** * Configurable XSLT-driven Crosswalk * * This is the superclass of the XSLT dissemination and submission crosswalks. * These classes let you can create many different crosswalks between * DSpace internal data and any XML without changing any code, just * XSL transformation (XSLT) stylesheets. * Each configured stylesheet appears as a new plugin name, although they all * share the same plugin implementation class. * * The XML transformation must produce (for submission) or expect (for * dissemination) a document in DIM - DSpace Intermediate Metadata format. * See * http://wiki.dspace.org/DspaceIntermediateMetadata for details. * Configuration * Prepare your DSpace configuration as follows: * * A submission crosswalk is described by a * configuration key like * crosswalk.submission.PluginName.stylesheet = path * The alias names the Plugin name, * and the path value is the pathname (relative to dspace.dir/config) * of the crosswalk stylesheet, e.g. "mycrosswalk.xslt" * * For example, this configures a crosswalk named "LOM" using a stylesheet * in config/crosswalks/d-lom.xsl under the DSpace "home" directory: * crosswalk.submission.stylesheet.LOM = crosswalks/d-lom.xsl * * A dissemination crosswalk is described by a * configuration key like * crosswalk.dissemination.PluginName.stylesheet = path The alias names the Plugin name, * and the path value is the pathname (relative to dspace.dir/config) * of the crosswalk stylesheet, e.g. "mycrosswalk.xslt" * * You can have two names point to the same crosswalk, * just add two configuration entries with the same path, e.g. * * crosswalk.submission.MyFormat.stylesheet = crosswalks/myformat.xslt * crosswalk.submission.almost_DC.stylesheet = crosswalks/myformat.xslt * * * NOTE: This plugin will automatically reload any XSL stylesheet that * was modified since it was last loaded. This lets you edit and test * stylesheets without restarting DSpace. * * You must use the PluginManager to instantiate an * XSLT crosswalk plugin, e.g. * IngestionCrosswalk xwalk = PluginManager.getPlugin(IngestionCrosswalk.class, "LOM"); * * Since there is significant overhead in reading the properties file to * configure the crosswalk, and a crosswalk instance may be used any number * of times, we recommend caching one instance of the crosswalk for each * alias and simply reusing those instances. The PluginManager * does this automatically. * * @author Larry Stone * @version $Revision: 1.1 $ */ public abstract class XSLTCrosswalk extends SelfNamedPlugin { /** log4j category */ private static Logger log = Logger.getLogger(XSLTCrosswalk.class); /** * DSpace XML Namespace in JDOM form. */ public static final Namespace DIM_NS = Namespace.getNamespace("dim", "http://www.dspace.org/xmlns/dspace/dim"); /** Prefix for all lines in the config file for XSLT plugins. */ protected final static String CONFIG_PREFIX = "crosswalk."; private final static String CONFIG_STYLESHEET = ".stylesheet"; /** * Derive list of plugin name from DSpace configuration entries * for crosswalks. The direction parameter should be either * "dissemination" or "submission", so it looks for keys like * crosswalk.submission.{NAME}.stylesheet */ protected static String[] makeAliases(String direction) { String prefix = CONFIG_PREFIX+direction+"."; String suffix = CONFIG_STYLESHEET; List aliasList = new ArrayList(); Enumeration pe = ConfigurationManager.propertyNames(); log.debug("XSLTCrosswalk: Looking for config prefix = "+prefix); while (pe.hasMoreElements()) { String key = (String)pe.nextElement(); if (key.startsWith(prefix) && key.endsWith(suffix)) { log.debug("Getting XSLT plugin name from config line: "+key); aliasList.add(key.substring(prefix.length(), key.length()-suffix.length())); } } return (String[])aliasList.toArray(new String[aliasList.size()]); } private XSLTransformer transformer = null; private File transformerFile = null; private long transformerLastModified = 0; /** * Initialize the Transformation stylesheet from configured stylesheet file. * @param prefix the direction of xwalk, either "submission" or * "dissemination" * @return transformer or null if there was error initializing. */ protected XSLTransformer getTransformer(String direction) { if (transformerFile == null) { String myAlias = getPluginInstanceName(); if (myAlias == null) { log.error("Must use PluginManager to instantiate XSLTCrosswalk so the class knows its name."); return null; } String cmPropName = CONFIG_PREFIX+direction+"."+myAlias+CONFIG_STYLESHEET; String fname = ConfigurationManager.getProperty(cmPropName); if (fname == null) { log.error("Missing configuration filename for XSLT-based crosswalk: no "+ "value for property = "+cmPropName); return null; } else { String parent = ConfigurationManager.getProperty("dspace.dir") + File.separator + "config" + File.separator; transformerFile = new File(parent, fname); } } // load if first time, or reload if stylesheet changed: if (transformer == null || transformerFile.lastModified() > transformerLastModified) { try { log.debug((transformer == null ? "Loading " : "Reloading")+ getPluginInstanceName()+" XSLT stylesheet from "+transformerFile.toString()); transformer = new XSLTransformer(transformerFile); transformerLastModified = transformerFile.lastModified(); } catch (XSLTransformException e) { log.error("Failed to initialize XSLTCrosswalk("+getPluginInstanceName()+"):"+e.toString()); } } return transformer; } }
