net.e6tech.elements.cassandra.etl

Interface TimeBatchStrategy<S>

Type Parameters:

S - source table from relation database

All Superinterfaces:

BatchStrategy<S,TimeBatch>, Strategy<TimeBatch>

public interface TimeBatchStrategy<S>
extends BatchStrategy<S,TimeBatch>

This interface is designed to extract data from relation database into Cassandra

Field Summary

Fields inherited from interface net.e6tech.elements.cassandra.etl.Strategy

logger

Method Summary

Modifier and Type	Method and Description
default java.util.List<S>	extract(TimeBatch context) Subclasses should not override this method.
java.util.List<S>	extractUpdate(TimeBatch context, LastUpdate lastUpdate) When overriding this method, the implementation MUST update the context's start and lastUpdate's lastUpdate with the last entry's modified time.
default void	initializeContext(TimeBatch context)
default int	run(TimeBatch context)

Methods inherited from interface net.e6tech.elements.cassandra.etl.BatchStrategy

load

Method Detail

extract

default java.util.List<S> extract(TimeBatch context)

Subclasses should not override this method. Instead, they should override extractUpdate.

Specified by:

extract in interface BatchStrategy<S,TimeBatch>

extractUpdate

java.util.List<S> extractUpdate(TimeBatch context,
                                LastUpdate lastUpdate)

When overriding this method, the implementation MUST update the context's start and lastUpdate's lastUpdate with the last entry's modified time. For example, context.setStart(s.getModifiedTime()); lastUpdate.update(s.getModifiedTime());

run

default int run(TimeBatch context)

Specified by:

run in interface BatchStrategy<S,TimeBatch>

Specified by:

run in interface Strategy<TimeBatch>

initializeContext

default void initializeContext(TimeBatch context)