Metacat

/**

 *      Name: DBWriter.java

 *   Purpose: A Class that reads in an XML text document and

 *            write its contents to a database connection using SAX

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

 *            National Center for Ecological Analysis and Synthesis

 *   Authors: Matt Jones

 *

 *   Version: '$Id: DBWriter.java 184 2000-06-21 02:57:19Z jones $'

 */

package edu.ucsb.nceas.metacat;

import org.xml.sax.*;

import java.io.*;

import java.net.URL;

import java.net.MalformedURLException;

import java.sql.*;

import java.util.Stack;

// Extensions to the SAX Interfaces for Namespace support.

import oracle.xml.parser.v2.XMLDocumentHandler;

import oracle.xml.parser.v2.DefaultXMLDocumentHandler;

import oracle.xml.parser.v2.NSName;

import oracle.xml.parser.v2.SAXAttrList;

import oracle.xml.parser.v2.SAXParser;

/**

 * A Class that reads in an XML text document and

 * write its contents to a database connection using SAX

 */

public class DBWriter {

  private Connection	conn = null;

  /**

   * the main routine used to test the DBWriter utility.

   * <p>

   * Usage: java DBWriter <filename>

   *

   * @param filename the filename to be loaded into the database

   */

  static public void main(String[] args) {

     if (args.length < 1)

     {

        System.err.println("Wrong number of arguments!!!");

        System.err.println("USAGE: java DBWriter <filename>");

        return;

     } else {

        try {

          String filename = args[0];

          // Open a connection to the database

          MetaCatUtil   util = new MetaCatUtil();

          Connection dbconn = util.openDBConnection();

          new DBWriter(filename, dbconn);

          System.out.println("Document processing finished for: " + filename);

        } catch (Exception e) {

          System.err.println("EXCEPTION HANDLING REQUIRED");

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

          e.printStackTrace(System.err);

        }

     }

  }

  /**

   * construct a new instance of the class to write an XML file to the database

   *

   * @param filename the filename to be loaded into the database

   * @param conn the database connection to which to write the XML file

   */

  public DBWriter( Reader xml, Connection conn)

                  throws IOException, 

                         SQLException, 

                         ClassNotFoundException

  {

    this.conn = conn;

    try {

        SAXParser parser = initializeParser(conn);

        conn.setAutoCommit(false);

        parser.parse(xml);

        conn.commit();

        conn.setAutoCommit(true);

      } catch (SAXParseException e) {

        conn.rollback();

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

      } catch (SAXException e) {

        conn.rollback();

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

      } catch (Exception e) {

        conn.rollback();

        System.err.println(e.toString());

      }

  }

  public DBWriter( String filename, Connection conn)

                  throws IOException, 

                         SQLException, 

                         ClassNotFoundException

  {

     this.conn = conn;

     FileReader xmlfile = new FileReader(new File(filename).toString());

     try {

       SAXParser parser = initializeParser(conn);

       conn.setAutoCommit(false);

       parser.parse(xmlfile);

       conn.commit();

       conn.setAutoCommit(true);

     } catch (SAXParseException e) {

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

     } catch (SAXException e) {

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

     } catch (Exception e) {

       System.err.println("from DBWriter:" + e.toString());

     }

  }

  private SAXParser initializeParser(Connection conn) {

    SAXParser parser = null;

    //

    // Set up the SAX document handlers for parsing

    //

    try {

      // Use the XMLDocumentHandler interface for namespace support

      // instead of org.xml.sax.DocumentHandler

      XMLDocumentHandler xmlDocHandler = new DBSAXHandler(conn);

      EntityResolver xmlEntityResolver = new DBEntityResolver(conn);

      DTDHandler xmlDTDHandler         = new DBDTDHandler(conn);

      // For all the other interface use the default provided by

      // Handler base

      HandlerBase defHandler = new HandlerBase();

      // Get an instance of the parser

      parser = new SAXParser();

      // Set Handlers in the parser

      // Set the DocumentHandler to XMLDocumentHandler

      parser.setDocumentHandler(xmlDocHandler);

      parser.setEntityResolver(xmlEntityResolver);

      parser.setDTDHandler(xmlDTDHandler);

      // Set the other Handler to the defHandler

      parser.setErrorHandler(defHandler);

    } catch (Exception e) {

       System.err.println(e.toString());

    }

    return parser;

  }

  /** Utility method to convert a file handle into a URL */

  static public URL fileToURL(File file) 

  {

     String path = file.getAbsolutePath();

     String fSep = System.getProperty("file.separator");

     if (fSep != null && fSep.length() == 1)

       path = path.replace(fSep.charAt(0), '/');

     if (path.length() > 0 && path.charAt(0) != '/')

       path = '/' + path;

     try {

       return new URL("file", null, path);

     }

     catch (java.net.MalformedURLException e) {

       /* According to the spec this could only happen if the file

	  protocol were not recognized. */

       throw new Error("unexpected MalformedURLException");

     }

  }

}