Bug 191404 Connection is still successful after delete drivers[0703]
Description: Create a Sqlserver datasource and dataset, then delete the jtds driver. Click "Test Connection" is still successful, and the dataset still works. Build Version:2.2.0.v20070607-0630 Steps to reproduce: 1. Add a jtds driver, and create a Sqlserver connection and dataset. 2. Go to "Manage JDBC Drivers" dialog, and delete the driver. 3. Click "Test Connection", the connection is successful. 4. Click "Preview Results" in "Edit Data Set" dialog, it works. Expected Result: Delete driver will lose the connection.
data/org.eclipse.birt.report.data.oda.jdbc/src/org/eclipse/birt/report/data/oda/jdbc/JDBCDriverManager.java
}
    
	/** 
	 * Searches extension registry for connection factory defined for driverClass. Returns an 
	 * instance of the factory if there is a connection factory for the driver class. Returns null
	 * otherwise.
	 */
	private IConnectionFactory getDriverConnectionFactory( String driverClass ) throws OdaException
	{
		loadDriverExtensions();
		
		IConnectionFactory factory = null;
		Object driverInfo = null;
		if ( driverClass != null )
			driverInfo = driverExtensions.get( driverClass);
		
		if ( driverInfo != null )
		{
			
			if ( driverInfo instanceof IConfigurationElement )
			{
				
				String factoryClass = ( (IConfigurationElement) driverInfo ).getAttribute( OdaJdbcDriver.Constants.DRIVER_INFO_ATTR_CONNFACTORY );
				try
				{
					factory = (IConnectionFactory) ( (IConfigurationElement) driverInfo ).createExecutableExtension( OdaJdbcDriver.Constants.DRIVER_INFO_ATTR_CONNFACTORY );
					logger.fine( "Created connection factory class "
							+ factoryClass + " for driverClass " + driverClass );
				}
				catch ( CoreException e )