K
- type of the grouping keyR0
- type of the aggregation result for stream-0public class GroupAggregateBuilder<K,R0> extends Object
BatchStageWithKey.aggregateBuilder()
on one of the stages to co-group
and refer to that method's Javadoc for further details.
Note: this is not a builder of AggregateOperation
. If that' s what you are looking for, go here
.
Modifier and Type | Method and Description |
---|---|
<T,R> Tag<R> |
add(BatchStageWithKey<T,K> stage,
AggregateOperation1<? super T,?,? extends R> aggrOp)
Adds another stage that will contribute its data to the aggregate
operation to be performed.
|
BatchStage<Map.Entry<K,ItemsByTag>> |
build()
Creates and returns a pipeline stage that performs the co-aggregation
of the stages registered with this builder object and emits a
Map.Entry(key, resultsByTag) for each distinct key. |
<OUT> BatchStage<OUT> |
build(DistributedBiFunction<? super K,ItemsByTag,OUT> mapToOutputFn)
Creates and returns a pipeline stage that performs the co-aggregation
of the stages registered with this builder object.
|
Tag<R0> |
tag0()
Returns the tag corresponding to the pipeline stage this builder
was obtained from.
|
@Nonnull public Tag<R0> tag0()
AggregateOperation
that you'll pass to build(aggrOp)
.@Nonnull public <T,R> Tag<R> add(@Nonnull BatchStageWithKey<T,K> stage, @Nonnull AggregateOperation1<? super T,?,? extends R> aggrOp)
AggregateOperation
that you'll pass to
build()
.@Nonnull public <OUT> BatchStage<OUT> build(@Nonnull DistributedBiFunction<? super K,ItemsByTag,OUT> mapToOutputFn)
ItemsByTag
and the mapToOutputFn
you
supply transforms it to the final result to emit. Use the tags you got
from this builder in the implementation of mapToOutputFn
to
access the results.OUT
- the output item typemapToOutputFn
- function that transforms the aggregation result into the output item@Nonnull public BatchStage<Map.Entry<K,ItemsByTag>> build()
Map.Entry(key, resultsByTag)
for each distinct key. The composite
aggregate operation places the results of the individual aggregate
operations in an ItemsByTag
. Use the tags you got from this
builder to access the results.Copyright © 2018 Hazelcast, Inc.. All rights reserved.