com.hazelcast.jet.pipeline

Interface GeneralStageWithGrouping<T,K>

Type Parameters:

T - type of the stream item

K - type of the grouping key

All Known Subinterfaces:

StageWithGrouping<T,K>, StreamStageWithGrouping<T,K>

public interface GeneralStageWithGrouping<T,K>

Represents an intermediate step when constructing a group-and-aggregate pipeline stage. This is the base type for the batch and stream variants.

Method Summary

Modifier and Type	Method and Description
DistributedFunction<? super T,? extends K>	keyFn() Returns the function that extracts the grouping key from stream items.

Method Detail

keyFn

@Nonnull
DistributedFunction<? super T,? extends K> keyFn()

Returns the function that extracts the grouping key from stream items. This function will be used in the aggregating stage you are about to construct using this object.