/*
 * @author                 : Mark Drake
 * @version                : 1.0
 * Development Environment : Oracle9i JDeveloper
 * Name of the File        : SimpleBulkLoader.java

 * Creation / Modification History :
 *  Shefali Bansal    25-Jan-2003      Modified
 *  Modifications Made:
 *  1. Provided for getting the Table for Insert from the BaseApplication class
 *  2. Renamed the doSomething() method as doBulkLoad() method
 *  3. Provided for user friendly messages for the Exceptions thrown
 */


//Package name
package oracle.otnsamples.xmldb.simplebulkloader.examples;


//IO Imports
import java.io.File;
import java.io.FileInputStream;

import java.io.IOException;

//Java SQL Imports
import java.sql.CallableStatement;

//JDBC imports
import java.sql.Connection;
import java.sql.SQLException;


//Import 'BaseApplication' base class
import oracle.otnsamples.xmldb.simplebulkloader.common.baseApp.BaseApplication;

//Import Alert class for trace purpose
import oracle.otnsamples.xmldb.simplebulkloader.common.trace.Alert;

//Oracle SQL Imports
import oracle.sql.CLOB;

/**

 * 'SimpleBulkLoader' class is part of the Simple Bulk Loader application. This
 * class demonstrates how to load a directory of XML files into XML DB using
 * Java. The important thing here is, it shows how using a single Temporary
 * CLOB one can upload multiple XML Files. In this application the XML files
 * are inserted into a 'PurchaseOrder' table which is of XMLType. The table
 * into which the XML files are to be loaded can be customized as required by
 * the user. This class extends the 'BaseApplication' class.
 */
public class SimpleBulkLoader extends BaseApplication {
  public CallableStatement m_InsertStatement = null;
  CLOB m_TemporaryCLOB = null;


  // Empty Constructor
  public SimpleBulkLoader(  ) {
  }

  /**
   * This method calls all the methods required for loading of XML files into
   * the XML DB. It first gets the DB connection information from the
   * connection.xml file. Once the connection info is available, it
   * establishes the connection. After establishing of the connection , it
   * reads through each of the XML files available in the source directory and
   * loads them into the database.

   *
   * @param args String Array
   *
   * @throws Exception
   */
  public void doBulkLoad( String[] args ) throws Exception {
    try {
      // Establish the database connection
      super.getConnectionSettings(  );
      super.createConnection(  );

      Connection connection = super.getConnection(  );


      // Get the source directory from which to load the XML files
      File sourceDirectory = new File( super.getTextNode( "sourceDirectory",
                                                          "c:\\temp" ) );

      // SQL Statement for inserting content into the required database table
      String INSERT_STATEMENT_TEXT = "insert into " + super.getTable(  ) +
                                     " values (xmltype(?))";

      // Get the Insert statement Object
      m_InsertStatement = connection.prepareCall( INSERT_STATEMENT_TEXT );

      // If the temporary CLOB has not yet been created, create new
      m_TemporaryCLOB = CLOB.createTemporary( connection, true,
                                              CLOB.DURATION_SESSION );


      // Upload the XML files in the source directory
      int uploadCount = uploadDirectory( connection, m_TemporaryCLOB,
                                         sourceDirectory );

      // Free the temporary CLOB
      m_TemporaryCLOB.freeTemporary(  );

      // Close the connection
      connection.close(  );
    } catch ( NullPointerException ex ) {
      System.out.println( "SimpleBulkLoader.doBulkLoad- The system cannot find the specified config XML file's path or the source directory path. NullPointerException" );
    } catch ( IOException ex ) {
      Alert.log( "SimpleBulkLoader.doBulkLoad- The system cannot find the path specified. IO:FileNotFound Exception" );
    }

  }

  /**
   * Loads all the XML files under the given source directory and its
   * subdirectories into the XML DB
   *
   * @param conn object specifying the DB connection information
   * @param clob specifying the temporary CLOB holding the XML content
   * @param sourceDirectory specifying the source directory where all the XML
   *        files are located
   *
   * @return int The count of the XML files in the source directory
   *
   * @throws java.sql.SQLException
   * @throws java.io.IOException
   */

  public int uploadDirectory( Connection conn, CLOB clob, File sourceDirectory )
                      throws java.sql.SQLException, java.io.IOException {
    int fileCounter = 0;

    try {
      // Get the list of all the XML files and sub directories in the source directory
      File[] files = sourceDirectory.listFiles(  );

      // Loop through this list
      for ( int i = 0; i < files.length; i++ ) {
        // Handle the case of a sub directory
        if ( files[i].isDirectory(  ) ) {
          fileCounter = fileCounter + uploadDirectory( conn, clob, files[i] );
        }
        else {
          // Handle the case of XML files
          // Load the content of the XML files into the XML DB

          uploadXMLFile( conn, clob, files[i] );
          fileCounter = fileCounter + 1;
        }
      }

      if ( files.length == 0 ) {
        Alert.log( "If you see this message it means the directory specified or some sub directory of the directory specified does not contain any XML file" );
      }

      // Commit the insertion of XML content in the XML DB
      conn.commit(  );
    }
     catch ( NullPointerException ex ) {
      Alert.log( "SimpleBulkLoader.uploadDirectory:The system cannot find the XML files in the source directory location specified : FileNotFound Exception" );
    }

    // Return the count of the XML files in the source directory
    return fileCounter;

  }

  /**
   * Loads the content of an XML file into the XML DB
   *
   * @param conn object specifying the DB connection information
   * @param clob specifying the temporary CLOB holding the XML content
   * @param xmlFile specifying the XML file to be loaded
   *
   * @throws java.sql.SQLException
   * @throws java.io.IOException
   */
  public void uploadXMLFile( Connection conn, CLOB clob, File xmlFile )
                     throws java.sql.SQLException, java.io.IOException {
    boolean result;

    // Write the XML file content into the CLOB object
    writeToClob( clob, new FileInputStream( xmlFile ) );


    // Bind this CLOB to the Insert Statement
    m_InsertStatement.setClob( 1, clob );

    // Execute the Insert Statement
    result = m_InsertStatement.execute(  );
    clob.trim( 0 );
    System.out.println( "XMLLoader: Uploaded File " +
                        xmlFile.getAbsoluteFile(  ) );
  }

  /**
   * Main method for this class
   *
   * @param args Array
   */
  public static void main( String[] args ) {
    try {
      // Instantiate the SimpleBulkLoader class
      SimpleBulkLoader app = new SimpleBulkLoader(  );


      // Call the doBulkLoad() method load all the XML files under the given
      // directory and its subdirectories into the XML DB
      app.doBulkLoad( args );
    }
     catch ( Exception e ) {
      Alert.log( e );
    }
  }
}