Metacat

/**

 *  '$RCSfile$'

 *    Purpose: A class that gets Accession Number, check for uniqueness

 *             and register it into db

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

 *             National Center for Ecological Analysis and Synthesis

 *    Authors: Jivka Bojilova, Matt Jones

 *    Release: @release@

 *

 *   '$Author: bojilova $'

 *     '$Date: 2000-12-14 15:07:30 -0800 (Thu, 14 Dec 2000) $'

 * '$Revision: 618 $'

 */

package edu.ucsb.nceas.metacat;

import java.net.*;

import java.sql.*;

/**

 * (on insert of XML document)

 * Generates a unique Accession Number or if provided check it 

 * for uniqueness and register it into the db connection 

 * (on update or delete of XML document)

 * Check for existance of provided Accession Number

 * 

 */

public class AccessionNumber  {

  private Connection conn = null;

  private String sitecode = null;

  private String sep = null;

  /** 

   * Construct an AccessionNumber 

   */

  public AccessionNumber () 

         throws SQLException, ClassNotFoundException  {

    MetaCatUtil util = new MetaCatUtil();

    this.sitecode = util.getOption("sitecode");

    this.sep = util.getOption("accNumSeparator");

    // Open a connection to the database

    this.conn = util.openDBConnection();

  }  

  /** 

   * Construct an AccessionNumber

   *

   * @param conn the db connection to read from and write Accession# to

   */

  public AccessionNumber (Connection conn) {

    MetaCatUtil util = new MetaCatUtil();

    this.sitecode = util.getOption("sitecode");

    this.sep = util.getOption("accNumSeparator");

    this.conn = conn;

  }

  /**

   * Generate an Accession Number of form <sidecode>.<createdate>

   */

  public String generate(String accNumber, String action) 

                throws AccessionNumberException, SQLException 

  {

    try {

      // INSERT

      if ( action.equals("INSERT")) {

        // get a new Accession#

        if ( accNumber == null ) {

          String sitecode = getSitecode();

          String uniqueid = getUniqueID();

          return sitecode + sep + uniqueid;

        // Accession# is not used; return it

        } else if ( !accNumberUsed(accNumber) ) {

          return accNumber;

        // Accession# is used; throw an exception to prevent the insertion

        } else {

          throw new AccessionNumberException

                    ("Accession number " + accNumber + " is already in use.");

        }

      // UPDATE or DELETE

      } else if ( action.equals("UPDATE") || action.equals("DELETE")) {

        // Accession# is not provided; throw an exception to prevent the action

        if ( accNumber == null ) {

          throw new AccessionNumberException("Accession number is required.");

        // Accession# is not current (not in xml_documents); throw an exception

        } else if ( !accNumberIsCurrent(accNumber) ) {

          throw new AccessionNumberException

          ("Document not found for Accession number " + accNumber);

        // Accession# is current (present in xml_documents); return it

        } else {

          return accNumber;

        }

      }

    } catch (SQLException e) {

      throw new SQLException

      ("Error on AccessionNumber.generate(accNumber, action): "+e.getMessage());

    }    

    // never comes here

    throw new

    AccessionNumberException("Fatal Error in accession number generation.");

  }

  // get local sitecode

  private String getSitecode()

  {

    return this.sitecode;

  }

  // get Unique ID from DB sequence

  private String getUniqueID () throws SQLException

  {

    String uniqueid;

    try {

      PreparedStatement pstmt;

      pstmt = conn.prepareStatement

              ("SELECT accnum_uniqueid_seq.nextval FROM dual");

      pstmt.execute();

      ResultSet rs = pstmt.getResultSet();

      boolean hasRow = rs.next();

      uniqueid = rs.getString(1);

      pstmt.close();

    } catch (SQLException e) {

      throw new 

      SQLException("Error on AccessionNumber.getUniqueID(): "+e.getMessage());

    }

    return uniqueid;

  }

  /** check for existence of Accesssion Number xml_acc_numbers table */

  public boolean accNumberUsed ( String accNumber )

                  throws SQLException {

    boolean hasAccNumber = false;

    try {

      PreparedStatement pstmt;

      pstmt = conn.prepareStatement(

                "SELECT 'x' FROM xml_documents " + 

                "WHERE docid LIKE ? " +

                "UNION " +

                "SELECT 'x' FROM xml_revisions " +

                "WHERE docid LIKE ?");

      pstmt.setString(1,accNumber);

      pstmt.setString(2,accNumber);

      pstmt.execute();

      ResultSet rs = pstmt.getResultSet();

      hasAccNumber = rs.next();

      pstmt.close();

    } catch (SQLException e) {

      throw new SQLException

      ("Error on AccessionNumber.accNumberUsed(accNumber): " + e.getMessage());

    }    

    return hasAccNumber;

  }    

  /** check for existence of Accesssion Number in xml_documents table */

  private boolean accNumberIsCurrent(String accNumber) throws SQLException {

    boolean hasCurrentAccNumber = false;

    try {

      PreparedStatement pstmt;

      pstmt = conn.prepareStatement(

                "SELECT 'x' FROM xml_documents " + 

                "WHERE docid LIKE ?");

      pstmt.setString(1, accNumber);

      pstmt.execute();

      ResultSet rs = pstmt.getResultSet();

      hasCurrentAccNumber = rs.next();

      pstmt.close();

    } catch (SQLException e) {

      throw new SQLException(

          "Error on AccessionNumber.accNumberIsCurrent(String accNumber): " +

          e.getMessage());

    }    

    return hasCurrentAccNumber;

  }    

}

/**

 * '$Log$

 * 'Revision 1.16  2000/12/06 17:59:03  berkley

 * 'made replication on insert or update us.  Also made a method in AccessionNumber public so that you can tell if an accession number has already been used.e place be

 * '

 * 'Revision 1.15  2000/11/30 22:41:32  bojilova

 * 'change the generation of Accession# in the form of <sidecode>.<createdate>

 * '

 * 'Revision 1.14  2000/09/28 18:05:46  bojilova

 * 'Changed to prevent the insertion if the provided Accession# is in use as Dan suggested.

 * '

 * 'Revision 1.13  2000/09/20 20:15:58  bojilova

 * 'change Assession# generation to use the same db connection

 * '

 * 'Revision 1.12  2000/08/30 18:19:41  bojilova

 * 'cleared static methods in AccessionNumber classes for fixing bug found

 * 'when multiple requests to the servlet at a time.

 * '

 * 'Revision 1.11  2000/08/14 20:53:33  jones

 * 'Added "release" keyword to all metacat source files so that the release

 * 'number will be evident in software distributions.

 * '

 * 'Revision 1.10  2000/06/27 04:31:07  jones

 * 'Fixed bugs associated with the new UPDATE and DELETE functions of

 * 'DBWriter.  There were problematic interactions between some static

 * 'variables used in DBEntityResolver and the way in which the

 * 'Servlet objects are re-used across multiple client invocations.

 * '

 * 'Generally cleaned up error reporting.  Now all errors and success

 * 'results are reported as XML documents from MetaCatServlet.  Need

 * 'to make the command line tools do the same.

 * '

 * 'Revision 1.9  2000/06/26 10:35:04  jones

 * 'Merged in substantial changes to DBWriter and associated classes and to

 * 'the MetaCatServlet in order to accomodate the new UPDATE and DELETE

 * 'functions.  The command line tools and the parameters for the

 * 'servlet have changed substantially.

 * '

 * 'Revision 1.8.2.5  2000/06/26 08:38:01  jones

 * 'Added DELETE feature to DBWriter.  Now takes an action "DELETE" and a

 * 'docid and will move the record from the xml_documents table to the

 * 'xml_revisions table.

 * 'Modified option parsing to support option symbols on command line.

 * '

 * 'Revision 1.8.2.4  2000/06/25 23:11:40  jones

 * 'Documentation update

 * '

 * 'Revision 1.8.2.3  2000/06/25 23:08:31  jones

 * 'Minor change to excpetion handling

 * ''

 */