com.boylesoftware.cb2
Interface FetchResultProcessor

public interface FetchResultProcessor

Classes that implement this interface can be passed along with a DAO fetch call to be installed into the DAO's result set processing loop to perform certain operations on the DMs as they are coming out of the DAO and before they get packed into an array and returned back to the caller. These fetch result processors need to be wrapped into FetchResultProcessorHandler objects before used with a fetch call. The FetchResultProcessorHandler allows to install the processor on a certain DM nesting level, so it is called only for the DMs formed on that level.

Version:

$Id: FetchResultProcessor.java,v 1.2 2004/04/20 16:00:58 levahim Exp $

Author:

Lev Himmelfarb

See Also:

FetchResultProcessorHandler, DAO.fetch(String, Set, Object [], String [], int, int, int, FetchResultProcessorHandler [], FetchResultDescriptor)

Method Summary

DataModel

processDM(DataModel dm, java.sql.ResultSet rs, int firstColumnIndex, int lastColumnIndex) Called by the DAO for each DM on a certain DM nesting level just after it has processed a result set row and populated the DM's fields.

Method Detail

processDM

public DataModel processDM(DataModel dm,
                           java.sql.ResultSet rs,
                           int firstColumnIndex,
                           int lastColumnIndex)
                    throws BLException,
                           java.sql.SQLException

Called by the DAO for each DM on a certain DM nesting level just after it has processed a result set row and populated the DM's fields.

Parameters:

dm - the DM created an populated by the DAO.

rs - reference to the result set.

firstColumnIndex - index of a column in the result set, which is the first column that belongs to the DM.

lastColumnIndex - index of a column in the result set, which is the last column that belongs to the DM.

Returns:

DM, which has to be taken by the DAO as the result of the row processing. If the implementation returns null, the DAO unconditionally aborts current row processing and nothing is added to the resulting array of DMs for this row. If multiple processors are installed on the same nesting level, others do not get called if one of them returns null.

Throws:

java.sql.SQLException - if a database error happens.

BLException - if a serious error happens during the DM processing.