Metacat

/**

 *  '$RCSfile$'

 *    Purpose: A class to asyncronously do delta-T replication checking

 *  Copyright: 2000 Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *    Authors: Chad Berkley

 *    Release: @release@

 *

 *   '$Author$'

 *     '$Date$'

 * '$Revision$'

 *

 * 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;

import java.io.StringReader;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.util.Hashtable;

import java.util.Vector;

import org.apache.xpath.XPathAPI;

import org.apache.xerces.parsers.DOMParser;

import org.w3c.dom.Attr;

import org.w3c.dom.NamedNodeMap;

import org.w3c.dom.NodeList;

import org.w3c.dom.Document;

import org.w3c.dom.Node;

import org.w3c.dom.NodeList;

import org.w3c.dom.DocumentType;

import org.apache.xerces.dom.DocumentTypeImpl;

import org.apache.xpath.objects.XObject;

import org.ecoinformatics.eml.EMLParser;

/**

 * This class will figure out which content type it is for a given data file.

 * First, from xml_relation to get all relative files to this data file.

 * Then from xml_documents to get physical files. From physical file pull out

 * the content type

 */

public class ContentTypeProvider

{

  private String dataFileId = null;

  private String contentType = null;

  private String packageType = null;

  private Hashtable contentTypeHash = new Hashtable();

  //Constant

  private String BETA = "beta";

  private String EML2 = "eml2";

  private String DEFAULTCONTENTTYPE = MetaCatUtil.

                                           getOption("defaultcontenttype");

  private String FORMATPATH = "//format";

  private String TEXT       = "text";

  private String TEXTYPE    ="text/plain";

  private String XML        = "xml";

  private String XMLTYPE    = "text/xml";

  private String HTML       = "HTML";

  private String HTMLTYPE   = "text/html";

  private String GIF        = "gif";

  private String GIFTYPE    = "image/gif";

  private String BMP        = "bmp";

  private String BMPTYPE    = "image/bmp";

  private String TAR        = "tar";

  private String TARTYPE    ="application/x-tar";

  private String ZIP        = "zip";

  private String ZIPTYPE    = "application/x-zip-compressed";

  private String BINARY     = "binary";

  private String BINARYTYPE = "application/octet-stream";

  private String ENTITYDOCTYPE = "entitydoctype";

  private String PHYSICALDOCTYPE = "physicaldoctype";

  /**

   * Constructor of ContentTypeProvider

   */

  public ContentTypeProvider(String docIdWithRevision)

  {

    dataFileId = MetaCatUtil.getDocIdFromString(docIdWithRevision);

    //get relative doclist for data file and package type

    Vector docLists = null;

    docLists = getRelativeDocIdList(dataFileId);

    if ( packageType == null)

    {

      // other situation, contenetype is default value

      contentType = DEFAULTCONTENTTYPE;

    }

    else if (packageType.equals(BETA))

    {

      // for beta package and get entity docid for the data file

      String entityDocid = getTargetDocIdForBeta(docLists, ENTITYDOCTYPE);

      // get physical docid for data file

      docLists = getRelativeDocIdList(entityDocid);

      String physicalDocId = getTargetDocIdForBeta(docLists, PHYSICALDOCTYPE);

      // if no physical docid assign to this data file, content type is default

      if (physicalDocId == null)

      {

        contentType = DEFAULTCONTENTTYPE;

      }

      else

      {

        parsePhysicalDocumentForBeta(physicalDocId);

      }

    }

    else if (packageType.equals(EML2))

    {

      // for eml2 package

    }

  }

  /** Method to get content type */

  public String getContentType()

  {

    return contentType;

  }//getContentType

  /* Get relative docid list and packagetype */

  private Vector getRelativeDocIdList(String id) 

  {

    Vector docList = new Vector();

    String sql = "SELECT packagetype, subject from xml_relation " + 

                 "where object = ?";

    ResultSet rs = null;

    PreparedStatement pStmt=null;

    DBConnection conn = null;

    int serialNumber = -1;

    try

    {

      //check out DBConnection

      conn=DBConnectionPool.getDBConnection

                                   ("ContentTypeProvider.getRelativeDocIdlist");

      serialNumber=conn.getCheckOutSerialNumber();

      pStmt = conn.prepareStatement(sql);

      // binding value

      pStmt.setString(1, id);

      //execute query

      pStmt.execute();

      rs = pStmt.getResultSet();

      // get result list

      String packType = null;

      while (rs.next())

      {

        packType = rs.getString(1);

        String subject = rs.getString(2);

        // get rid of duplicate record and add the docid into vector

        if (!docList.contains(subject))

        {

          docList.add(subject);

        }

      }//while

      // set up data package type

      if ((MetaCatUtil.getOptionList(MetaCatUtil.getOption("packagedoctype"))).

                                     contains(packType))

      {

        //this is beta4 or beta6 version

        MetaCatUtil.debugMessage("This is beta package", 30);

        packageType = BETA;

      }

      else if ((MetaCatUtil.getOptionList

               (MetaCatUtil.getOption("eml2namespace"))).contains(packType))

      {

        // this eml 2 document

        MetaCatUtil.debugMessage("This is EML2 package", 30);

        packageType = EML2;

      }

    }//try

    catch(SQLException e)

    {

      MetaCatUtil.debugMessage("ContenTypProvider.getRelativeDoclist1 " +

                             e.getMessage(), 30);

    }//catch

    finally

    {

      try

      {

        pStmt.close();

      }

      catch (SQLException ee)

      {

        MetaCatUtil.debugMessage("ContenTypProvider.getRelativeDoclist2 " +

                             ee.getMessage(), 30);

      }

      finally

      {

        DBConnectionPool.returnDBConnection(conn, serialNumber);

      }

    }//finally

    return docList;

  }// getRelativeDocIdList

  /* Method to get physical document for data file in xml_documents table for

   * beta eml package

   */

  private String getTargetDocIdForBeta(Vector list, String targetType)

  {

    String docId = null;

    // make sure list is not empty

    if (list.isEmpty())

    {

      return docId;

    }

    // get sql command

    String sql = "SELECT doctype, docid from xml_documents where docid in (";

    // the first element

    sql = sql + "'"+(String)list.elementAt(0) + "'";

    for (int i=1; i<list.size(); i++)

    {

      String docid = (String) list.elementAt(i);

      sql = sql + ", '" + docid + "'";

    }//for

    // add parensis

    sql = sql + ")";

    MetaCatUtil.debugMessage("SQL for select doctype: "+ sql, 35);

    ResultSet rs = null;

    PreparedStatement pStmt=null;

    DBConnection conn = null;

    int serialNumber = -1;

    try

    {

      //check out DBConnection

      conn=DBConnectionPool.getDBConnection

                                 ("ContentTypeProvider.setPhycialDocIdForBeta");

      serialNumber=conn.getCheckOutSerialNumber();

      pStmt = conn.prepareStatement(sql);

      //execute query

      pStmt.execute();

      rs = pStmt.getResultSet();

      // get result list

      while (rs.next())

      {

        String packType = rs.getString(1);

        String targetId  = rs.getString(2);

        // find physical document

        if ((MetaCatUtil.getOptionList(MetaCatUtil.getOption(targetType))).

                                     contains(packType))

       {

         // assign physical document and jump out the while loop

         docId = targetId;

         break;

       }

      }//while

    }//try

    catch(SQLException e)

    {

      MetaCatUtil.debugMessage("ContenTypProvider.setPhysicalDocIdForBeta1 " +

                             e.getMessage(), 30);

    }//catch

    finally

    {

      try

      {

        pStmt.close();

      }

      catch(SQLException ee)

      {

        MetaCatUtil.debugMessage("ContenTypProvider.setPhysicalDocIdForBeta2 " +

                             ee.getMessage(), 30);

      }//catch

      finally

      {

        DBConnectionPool.returnDBConnection(conn, serialNumber);

      }

    }//finally

    MetaCatUtil.debugMessage("!!!!!!!!!target docid is: "+ docId + " "+

                             "for target doctype: "+targetType, 25);

    return docId;

  }

  /* Parser the beta physical document and find the value in format element*/ 

  private void parsePhysicalDocumentForBeta(String physicalDocid)

  {

    String xmlDoc = null;

    try

    {

      DocumentImpl doc = new DocumentImpl(physicalDocid);

      xmlDoc = doc.toString();

    }

    catch (Exception e)

    {

      contentType = DEFAULTCONTENTTYPE;

      MetaCatUtil.debugMessage("Error in ContentTypeProvider." +

                         "parsePhysicalDocumentForBeta()" + e.getMessage(), 30);

      return;

    }

      // get format element's text value

    String format = getTextValueFromPath(new StringReader(xmlDoc), FORMATPATH);

    if (format == null)

    {

      // if couldn't find the format, set contentype default value;

      contentType = DEFAULTCONTENTTYPE;

    }

    else

    {

      // if can find a format and look up from hash to get value

      contentType = lookUpContentType(format);

      // couldn't find the content type for this format in hash table

      if (contentType == null)

      {

        //set default vlaue

        contentType = DEFAULTCONTENTTYPE;

      }//if

    }//else

  }//parsePhysicalDocumentForBeta

  private String getTextValueFromPath(StringReader xml, String xPath)

  {

    String textValue = null;

    // get nodelist from doc by path

    try

    {

      NodeList list = EMLParser.getPathContent(xml, xPath);

      Node elementNode = list.item(0);

      Node textNode = elementNode.getFirstChild();

      if (textNode.getNodeType() == Node.TEXT_NODE)

      {

        textValue = textNode.getNodeValue();// get value

      }

    }

    catch (Exception e)

    {

      MetaCatUtil.debugMessage("error in ContentTypeProvider."+

                               "getTextValueFromPath: "+e.getMessage(), 30);

    }

    MetaCatUtil.debugMessage("The text value for " + xPath + " is: "+ 

                              textValue, 30);

    return textValue;

  }//getTextValueFromPath

  /* A method to look up contentype */

  private String lookUpContentType(String format)

  {

    String newFormat = null;

    constructContentHashTable();

    newFormat = format.toLowerCase().trim();

    String type = null;

    type = (String)contentTypeHash.get(newFormat);

    MetaCatUtil.debugMessage("contentType looked from hashtalbe is: " +

                              type, 30);

    return type;

  }// lookupcontentypes

  /* Construct content type hashtable */

  private void constructContentHashTable()

  {

    contentTypeHash.put(TEXT, TEXTYPE);

    contentTypeHash.put(XML, XMLTYPE);

    contentTypeHash.put(HTML,HTMLTYPE);

    contentTypeHash.put(GIF, GIFTYPE);

    contentTypeHash.put(BMP, BMPTYPE);

    contentTypeHash.put(TAR, TARTYPE);

    contentTypeHash.put(ZIP, ZIPTYPE);

    contentTypeHash.put(BINARY, BINARYTYPE);

  }//constructrContentHashTable();

  public static void main(String[] argus)

  {

     try

     {

       DBConnectionPool pool = DBConnectionPool.getInstance();

       ContentTypeProvider provider = new ContentTypeProvider("tao.9830");

       String str = provider.getContentType();

       MetaCatUtil.debugMessage("content type is : " + str, 20);

     }

     catch(Exception e)

     {

       MetaCatUtil.debugMessage("erorr in Schemalocation.main: " + 

                                e.getMessage(), 30);

     }

  }

}//ContentTypeProvider