Metacat

/**

 *        Name: DBDTDHandler.java

 *     Purpose: A Class that implements org.xml.sax.DTDHandler interface

 *              for resolving external entities

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

 *              National Center for Ecological Analysis and Synthesis

 *     Authors: Jivka Bojilova

 *

 *     Version: '$Id: DBDTDHandler.java 74 2000-05-05 00:37:58Z jones $'

 */

package edu.ucsb.nceas.metacat;

import org.xml.sax.*;

import java.sql.*;

import java.net.URL;

import java.net.MalformedURLException;

import java.util.Stack;

import java.util.EmptyStackException;

/** 

 * A database aware Class implementing DTDHandler interface for the SAX parser to

 * call when processing the XML stream and intercepting notations and unparsed entities

 */

public class DBDTDHandler implements DTDHandler

{

   private Connection	conn = null;

   /** Construct an instance of the DBDTDHandler clas

    *

    * @param conn the JDBC connection to which information is written

    */

   public DBDTDHandler(Connection conn)

   {

      this.conn = conn;

   }

   /** Notation declarations are not signaled */

   public void notationDecl(String name, String publicId, String systemId)

            throws SAXException

   {

    System.out.println("from DBDTDHandler.notationDecl");

    System.out.println(name);

    System.out.println(publicId);

    System.out.println(systemId);

    return;

   }

   /** All are reported after startDocument and before startElement event*/

   public void unparsedEntityDecl(String name, String publicId, String systemId, String notationName)

            throws SAXException

   {

    System.out.println("from DBDTDHandler.unparsedEntityDecl");

    System.out.print(name);

    System.out.print(publicId);

    System.out.print(systemId);

    System.out.println(notationName);

    Connection conn = DBEntityResolver.conn;

    String doctype = DBEntityResolver.doctype;

    if ( getEntitySystemID(conn, doctype, publicId) == "" ) 

        registerEntityPublicID(conn, doctype, publicId, systemId);

    return;

   }

   /** Look at db XML Catalog to get System ID (if any) for that Public ID and doctype.

     * Return empty string if there are not */

   private String getEntitySystemID (Connection conn, String doctype, String publicId)

   {

        String system_id = "";

        Statement stmt;

        try {

          stmt = conn.createStatement();

          stmt.execute("SELECT system_id FROM xml_catalog_entities " + 

                       "WHERE entity_type = 'ENTITY' AND source_doctype = '" + doctype + "' AND public_id = '" + publicId + "'");

          try {

            ResultSet rs = stmt.getResultSet();

            try {

              boolean tableHasRows = rs.next();

              if (tableHasRows) {

                try {

                  system_id = rs.getString(1);

                } catch (SQLException e) {

                  System.out.println("DBEntityResolver.getEntitySystemID() - Error with getString: " + e.getMessage());

                }

              }

            } catch (SQLException e) {

              System.out.println("DBEntityResolver.getEntitySystemID() - Error with next: " + e.getMessage());

            }

          } catch (SQLException e) {

            System.out.println("DBEntityResolver.getEntitySystemID() - Error with getrset: " + e.getMessage());

          }

          stmt.close();

        } catch (SQLException e) {

          System.out.println("DBEntityResolver.getEntitySystemID() - Error getting id: " + e.getMessage());

        }

        // return the selected System ID

        return system_id;

   }

   /** Register Public ID in db XML Catalog */

   private void registerEntityPublicID (Connection conn, String doctype, String publicId, String systemId)

   {

        try {

          conn.setAutoCommit(false);

          PreparedStatement pstmt;

          pstmt = conn.prepareStatement(

                "INSERT INTO xml_catalog_entities (entity_id, entity_name, entity_type, source_doctype, public_id, system_id) " +

                "VALUES (null, null, 'ENTITY', ?, ?, ?)");

          // Bind the values to the query

          pstmt.setString(1, doctype);

          pstmt.setString(2, publicId);

          pstmt.setString(3, systemId);

          // Do the insertion

          pstmt.execute();

          pstmt.close();

          conn.commit();

          conn.setAutoCommit(true);

        } catch (SQLException e) {

          System.out.println(e.getMessage());

        }

   }

}