Metacat

/**

 *  '$RCSfile: XSLTransform.java,v $'

 *  Copyright: 2003 Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *

 *   '$Author: jones $'

 *     '$Date: 2003/08/18 20:27:03 $'

 * '$Revision: 1.4 $'

 *

 * This program 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 2 of the License, or

 * (at your option) any later version.

 *

 * This program 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 this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

package edu.ucsb.nceas.metacat.util;

import java.io.*;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.util.Enumeration;

import java.util.Hashtable;

import java.util.Vector;

import org.apache.log4j.Logger;

import edu.ucsb.nceas.metacat.DBConnection;

import edu.ucsb.nceas.metacat.DBConnectionPool;

import edu.ucsb.nceas.metacat.DocumentImpl;

import edu.ucsb.nceas.metacat.DocumentImplWrapper;

import edu.ucsb.nceas.metacat.McdbException;

import edu.ucsb.nceas.metacat.service.PropertyService;

import javax.xml.transform.TransformerFactory;

import javax.xml.transform.Transformer;

import javax.xml.transform.stream.StreamSource;

import javax.xml.transform.stream.StreamResult;

import javax.xml.transform.TransformerException;

import javax.xml.transform.TransformerConfigurationException;

import javax.xml.transform.URIResolver;

import org.ecoinformatics.eml.EMLParser;

/**

 * A Class that transforms older eml version to newer eml version utitlizing XSL style sheets. 

 */

public class EMLVersionsTransformer {

	private static Logger logMetacat = Logger.getLogger(EMLVersionsTransformer.class);

	private static String eml210StyleFile = null;

	static{

		try

		{

			eml210StyleFile =PropertyService.getProperty("application.deployDir")+"/"+PropertyService

			.getProperty("application.context")+ "/style/common/eml201to210.xsl"; //eml201to210.xsl place

		}

		catch(Exception e)

		{

			logMetacat.warn("Couldn't get eml201to210.xsl stylesheet");

		}

	}

	private static String DOT = ".";

    /**

     * Public constructor because all methods are static and do not need 

     * an instance.

     */

    public EMLVersionsTransformer() 

    {

    }

    /**

     * Method to upgrade old versions of eml to new version

     */

    public void upgrade()

    {

    	upgradeEML200ToEML210();

    }

    /*

     * Upgrade every eml200 or eml210 documents into eml210

     */

    private  void upgradeEML200ToEML210()

    {

    	Vector list = getEML2DocList();

    	if(list != null)

    	{

    		for(int i=0; i<list.size(); i++)

    		{

    			OwnerAndDocid pair = (OwnerAndDocid)list.elementAt(i);

    			String docid = pair.getDocid();

    			String owner = pair.getOwner();

    			try

    			{

    				handleSingleEML200Document(docid, owner);

    			}

    			catch(Exception e)

    			{

    				logMetacat.warn("The docid "+docid+" with owner "+owner+" couldn't be transformed to eml-2.1.0 since "+e.getMessage());

    			}

    		}

    	}

    }

    /*

     * Handle single eml201 or eml 200 document: read the document, transform it to eml210 document 

     * then save it to 210 document into metacat

     */

    private  void handleSingleEML200Document(String docidWithRev, String owner) throws Exception

    {

    	DocumentImpl docImpl = new DocumentImpl(docidWithRev);

    	String eml200Content = docImpl.toString();

    	StringReader eml200Source= new StringReader(eml200Content);

    	//PipedWriter eml210OutputAfterTransform = new PipedWriter();

    	//PipedReader eml210SourceForNewDoc = new PipedReader();

    	//eml210SourceForNewDoc.connect(eml210OutputAfterTransform);

    	StringWriter strWriter = new StringWriter();

    	String newId = increaseRevisionNumber(docidWithRev);

    	if(newId != null)

    	{

    	     transformEML200ToEML210(eml200Source, eml210StyleFile,  strWriter, newId);

    	     String eml210Content = "";

    	     strWriter.write(eml210Content);

    	     String rule = DocumentImpl.EML210;

             // using emlparser to check id validation

             EMLParser parser = new EMLParser(eml210Content);

             DocumentImplWrapper documentWrapper = new DocumentImplWrapper(rule, true);

             StringReader xml = new StringReader(eml210Content);

             String  doAction = "UPDATE";

             String pub = null;

             String []groups = null;

             DBConnection dbconn = null;

             StringReader dtd = null;

             int serialNumber = -1;

             try

             {

            	 dbconn = DBConnectionPool

                 .getDBConnection("EMLVersionsTransformer.handleSingleEML200Document");

                  serialNumber = dbconn.getCheckOutSerialNumber();

                  documentWrapper.write(dbconn, xml, pub, dtd,

                          doAction, newId, owner, groups);

                  logMetacat.warn("Doc "+docidWithRev+"was transformed to eml210 with new id "+newId);

             }

             catch(Exception e)

             {

            	 throw e;

             }

             finally

             {

            	 // Return db connection

                 DBConnectionPool.returnDBConnection(dbconn, serialNumber);

             }

    	}

    	else

    	{

    		logMetacat.warn("Couldn't increase docid "+docidWithRev+"'s revision");

    	}

    }

    /*

     * Transform single eml201 (Reader) to eml 210 (Writer)

     */

    private static void transformEML200ToEML210(Reader reader, String xslfile, Writer writer, String packageid) throws Exception{    

        	Hashtable param = null;

            if (packageid != null)

            {

            	param = new Hashtable();

            	param.put("package-id", packageid);

            }

            EMLVersionsTransformer.transform(reader, xslfile, writer, param);

    }

    /*

     * Transform an XML document using an XSLT stylesheet to another format,

     * probably HTML or another XML document format.

     *

     * @param doc the document to be transformed

     * @param xslSystemId the system location of the stylesheet

     * @param pw the PrintWriter to which output is printed

     * @param params some parameters for inclusion to the transformation

     */

    private static void transform(Reader doc, String xslSystemId,

        Writer pw, Hashtable param) throws Exception

    {

            StreamSource xslSource = 

                new StreamSource(xslSystemId);

            xslSource.setSystemId(xslSystemId);

            // Create a stylesheet from the system id that was found

            TransformerFactory tFactory = TransformerFactory.newInstance();

            Transformer transformer = tFactory.newTransformer(xslSource);

            // Set up parameters for transformation

            if ( param != null) {

                Enumeration en = param.keys();

                while (en.hasMoreElements()) {

                    String key =(String)en.nextElement();

                    String value = ((String)(param.get(key)));

                    transformer.setParameter(key, value);

                }

            }

            // Run the transform engine

            StreamSource ss = new StreamSource(doc);

            StreamResult sr = new StreamResult(pw);

            transformer.transform(ss, sr);

    }

    /*

     * Get list of document (docid and owner) which type is eml200 or eml201. 

     * The docid in the list will have revision number too.

     */

    private Vector getEML2DocList()

    {

    	Vector list = new Vector();

    	 DBConnection dbconn = null;

         int serialNumber = -1;

         String sql = "select docid, rev, user_owner from xml_documents where doctype like 'eml://ecoinformatics.org/eml-2.0.1' or doctype like 'eml://ecoinformatics.org/eml-2.0.0'";

         PreparedStatement pstmt = null;

         try {

             dbconn = DBConnectionPool

                     .getDBConnection("EMLVersionsTransformer.getEML2DocList");

             serialNumber = dbconn.getCheckOutSerialNumber();

             pstmt = dbconn.prepareStatement(sql.toString());

             pstmt.execute();

             ResultSet rs = pstmt.getResultSet();

             boolean tableHasRows = rs.next();

             if (tableHasRows) {

                 String docidWithoutRev = rs.getString(1);

                 int rev = rs.getInt(2);

                 String owner = rs.getString(3);

                 String docidWithRev = docidWithoutRev+DOT+rev;

                 logMetacat.info("The docid "+docidWithRev+" with owner "+owner+" will be added into list which will be transformed to eml-2.1.0");

                 OwnerAndDocid pair = new OwnerAndDocid(owner, docidWithRev);;

                 list.add(pair);

                 tableHasRows = rs.next();

             }

             pstmt.close();

        } catch (SQLException e) {

             logMetacat.error("error in DocumentImpl.getDocumentInfo: "

                + e.getMessage());

             e.printStackTrace(System.out);

        } finally {

            try {

                 pstmt.close();

            } catch (SQLException ee) {

              logMetacat.error(

                    "error in DocumentImple.getDocumentInfo: "

                            + ee.getMessage());

           } finally {

              DBConnectionPool.returnDBConnection(dbconn, serialNumber);

        }

      }

      return list;

    }

    /*

     * Increase revision number for the given docid. tao.1.1 will be tao.1.2. null will be returned

     * if couldn't increase it.

     */

    private static String increaseRevisionNumber(String docidWithRev)

    {

    	String newid = null;

    	try

    	{

    	  if (docidWithRev != null)

    	  {

    		int index = docidWithRev.lastIndexOf(DOT);

    		if (index != -1)

    		{

    			String firstTwoParts = docidWithRev.substring(0,index);

    			String revStr = docidWithRev.substring(index+1);

    			Integer revObj = new Integer(revStr);

    			int rev = revObj.intValue();

    			rev= rev+1;

    			newid = firstTwoParts+DOT+rev;

    		}

    	  }

    	}

    	catch(Exception e)

    	{

    		logMetacat.warn("Couldn't increase revision number since "+e.getMessage());

    	}

    	return newid;

    }

    /*

     * Class reprents a document's docid and its owner 

     * @author tao

     *

     */

    class OwnerAndDocid{

    	private String owner = null;

    	private String docidWithRev = null;

    	public OwnerAndDocid(String owner, String docidWithRev)

    	{

    		this.owner = owner;

    		this.docidWithRev = docidWithRev;

    	}

    	public String getOwner()

    	{

    		return owner;

    	}

    	public String getDocid()

    	{

    		return docidWithRev;

    	}

    }

}