org.springframework.data.cassandra.core.cql

Interface RowCallbackHandler

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface RowCallbackHandler

An interface used by CqlTemplate for processing rows of a ResultSet on a per-row basis. Implementations of this interface perform the actual work of processing each row but don't need to worry about exception handling. DriverExceptions will be caught and handled by the calling CqlTemplate.

In contrast to a ResultSetExtractor, a RowCallbackHandler object is typically stateful: It keeps the result state within the object, to be available for later inspection.

Consider using a RowMapper instead if you need to map exactly one result object per row, assembling them into a List.

Author:

Mark Paluch

See Also:

CqlTemplate, RowMapper, ResultSetExtractor

Method Summary

Modifier and Type	Method and Description
void	processRow(com.datastax.driver.core.Row row) Implementations must implement this method to process each row of data in the ResultSet.

Method Detail

processRow

void processRow(com.datastax.driver.core.Row row)
         throws com.datastax.driver.core.exceptions.DriverException

Implementations must implement this method to process each row of data in the ResultSet. This method is only supposed to extract values of the current row.

Exactly what the implementation chooses to do is up to it: A trivial implementation might simply count rows, while another implementation might build an XML document.

Parameters:

row - the Row to process (pre-initialized for the current row).

Throws:

com.datastax.driver.core.exceptions.DriverException - if a DriverException is encountered getting column values (that is, there's no need to catch DriverException).