code: @Override
  	public void configure(Configuration parameters) {
  		boolean needConfigure = isFieldNullOrEmpty(this.query) || isFieldNullOrEmpty(this.dbURL);
  		if (needConfigure) {
  			this.driverName = parameters.getString(DRIVER_KEY, null);
  			this.username = parameters.getString(USERNAME_KEY, null);
  			this.password = parameters.getString(PASSWORD_KEY, null);
  			this.query = parameters.getString(QUERY_KEY, null);
  			this.dbURL = parameters.getString(URL_KEY, null);
  		}
  
  		try {
  			prepareQueryExecution();
  		} catch (SQLException e) {
  			throw new IllegalArgumentException("Configure failed:\t!", e);
  		}
  	}
docs: Configures this JDBCInputFormat. This includes setting the connection
  parameters (if necessary), establishing the connection and executing the
  query.
  
  @param parameters
  Configuration containing all or no parameters.