QueryCopySource.java :  » Database-Client » SQL-Workbench » workbench » db » datacopy » Java Open Source

/*
 * QueryCopySource.java
 *
 * This file is part of SQL Workbench/J, http://www.sql-workbench.net
 *
 * Copyright 2002-2008, Thomas Kellerer
 * No part of this code maybe reused without the permission of the author
 *
 * To contact the author please send an email to: support@sql-workbench.net
 *
 */
package workbench.db.datacopy;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import workbench.db.WbConnection;
import workbench.db.importer.RowDataProducer;
import workbench.db.importer.RowDataReceiver;
import workbench.interfaces.JobErrorHandler;
import workbench.log.LogMgr;
import workbench.storage.ResultInfo;
import workbench.storage.RowData;
import workbench.util.MessageBuffer;
import workbench.util.SqlUtil;
import workbench.util.ValueConverter;

/**
 * @author  support@sql-workbench.net
 */
public class QueryCopySource
    implements RowDataProducer
{
  private RowDataReceiver receiver;
  private boolean keepRunning = true;
  private boolean regularStop = false;
  private WbConnection sourceConnection;
  private Statement retrieveStatement;
  private String retrieveSql;
  private boolean abortOnError;
  private boolean hasErrors = false;
  private boolean hasWarnings = false;
  private RowData currentRow;
  
  public QueryCopySource(WbConnection source, String sql)
  {
    this.sourceConnection = source;
    this.retrieveSql = sql;
  }

  public boolean hasErrors() { return this.hasErrors; }
  public boolean hasWarnings() { return this.hasWarnings; }
  
  public void setValueConverter(ValueConverter converter) {}
  
  public void setReceiver(RowDataReceiver rec)
  {
    this.receiver = rec;
  }

  public void start()
    throws Exception
  {
    LogMgr.logDebug("QueryCopySource.start()", "Using SQL: "+ this.retrieveSql);
    
    ResultSet rs = null;
    this.keepRunning = true;
    this.regularStop = false;
    try
    {
      this.retrieveStatement = this.sourceConnection.createStatementForQuery();
      rs = this.retrieveStatement.executeQuery(this.retrieveSql);
      ResultInfo info = new ResultInfo(rs.getMetaData(), this.sourceConnection);
      int colCount = info.getColumnCount();
      currentRow = new RowData(colCount);
      while (this.keepRunning && rs.next())
      {
        // RowData will make some transformation 
        // on the data read from the database
        // which works around some bugs in the Oracle
        // JDBC driver. Especially it will supply
        // CLOB data as a String which I hope will be
        // more flexible when copying from Oracle
        // to other systems
        currentRow.read(rs, info);
        if (!keepRunning) break;
        
        try
        {
          this.receiver.processRow(currentRow.getData());
        }
        catch (SQLException e)
        {
          if (abortOnError) throw e;
        }
      }
      
      // if keepRunning == false, cancel() was
      // called and we have to tell that the Importer
      // in order to do a rollback
      if (this.keepRunning || regularStop) 
      {
        // When copying a schema, we should not send an importFinished()
        // so that the DataImporter reports the table counts correctly
        this.receiver.importFinished();
      }
      else
      {
        this.receiver.importCancelled();
      }
    }
    finally
    {
      SqlUtil.closeAll(rs, retrieveStatement);
    }
  }

  public String getLastRecord()
  {
    if (currentRow == null) return null;
    return currentRow.toString();
  }
  
  public void stop()
  {
    this.regularStop = true;
    cancel();
  }
  
  public void cancel()
  {
    this.keepRunning = false;
    try
    {
      this.retrieveStatement.cancel();
    }
    catch (Exception e)
    {
      LogMgr.logWarning("QueryCopySource.cancel()", "Error when cancelling retrieve", e);
    }
    
  }

  public boolean isCancelled()
  {
    return !keepRunning && !regularStop;
  }
  
  public MessageBuffer getMessages()
  {
    return null;
  }

  public void setAbortOnError(boolean flag)
  {
    this.abortOnError = flag;
  }

  public void setCheckDependencies(boolean flag)
  {
    // not supported
  }
  
  public void setErrorHandler(JobErrorHandler handler)
  {
  }
}