Class Stream
- All Implemented Interfaces:
ResourceDeclarer<Stream>
,IAggregatableStream
There are five types of operations that can be performed on streams in Trident
1. **Partiton-Local Operations** - Operations that are applied locally to each partition and do not involve network transfer 2. **Repartitioning Operations** - Operations that change how tuples are partitioned across tasks(thus causing network transfer), but do not change the content of the stream. 3. **Aggregation Operations** - Operations that *may* repartition a stream (thus causing network transfer) 4. **Grouping Operations** - Operations that may repartition a stream on specific fields and group together tuples whose fields values are equal. 5. **Merge and Join Operations** - Operations that combine different streams together.
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionaddSharedMemory
(SharedMemory request) Add in request for shared memory that this component will use.aggregate
(Aggregator agg, Fields functionFields) aggregate
(CombinerAggregator agg, Fields functionFields) aggregate
(ReducerAggregator agg, Fields functionFields) aggregate
(Fields inputFields, Aggregator agg, Fields functionFields) aggregate
(Fields inputFields, CombinerAggregator agg, Fields functionFields) aggregate
(Fields inputFields, ReducerAggregator agg, Fields functionFields) applyAssembly
(Assembly assembly) Applies an `Assembly` to this `Stream`.## Repartitioning Operation.## Repartitioning Operation.Returns a stream consisting of the elements of this stream that match the given filter.Returns a stream consisting of the elements of this stream that match the given filter.flatMap
(FlatMapFunction function) Returns a stream consisting of the results of replacing each value of this stream with the contents produced by applying the provided mapping function to each value.flatMap
(FlatMapFunction function, Fields outputFields) Returns a stream consisting of the results of replacing each value of this stream with the contents produced by applying the provided mapping function to each value.getName()
Returns the label applied to the stream.global()
## Repartitioning Operation.## Grouping Operation.## Repartitioning Operation.## Repartitioning Operation.map
(MapFunction function) Returns a stream consisting of the result of applying the given mapping function to the values of this stream.map
(MapFunction function, Fields outputFields) Returns a stream consisting of the result of applying the given mapping function to the values of this stream.max
(Comparator<TridentTuple> comparator) This aggregator operation computes the maximum of tuples in a stream by using the givencomparator
withTridentTuple
s.This aggregator operation computes the maximum of tuples by the giveninputFieldName
and it is assumed that its value is an instance ofComparable
.<T> Stream
maxBy
(String inputFieldName, Comparator<T> comparator) This aggregator operation computes the maximum of tuples by the giveninputFieldName
in a stream by using the givencomparator
.min
(Comparator<TridentTuple> comparator) This aggregator operation computes the minimum of tuples in a stream by using the givencomparator
withTridentTuple
s.This aggregator operation computes the minimum of tuples by the giveninputFieldName
and it is assumed that its value is an instance ofComparable
.<T> Stream
minBy
(String inputFieldName, Comparator<T> comparator) This aggregator operation computes the minimum of tuples by the giveninputFieldName
in a stream by using the givencomparator
.Applies a label to the stream.parallelismHint
(int hint) Applies a parallelism hint to a stream.## Repartitioning Operation.partition
(CustomStreamGrouping partitioner) ## Repartitioning Operation.partitionAggregate
(Aggregator agg, Fields functionFields) partitionAggregate
(CombinerAggregator agg, Fields functionFields) partitionAggregate
(ReducerAggregator agg, Fields functionFields) partitionAggregate
(Fields inputFields, Aggregator agg, Fields functionFields) partitionAggregate
(Fields inputFields, CombinerAggregator agg, Fields functionFields) partitionAggregate
(Fields inputFields, ReducerAggregator agg, Fields functionFields) partitionBy
(Fields fields) ## Repartitioning Operation.partitionPersist
(StateFactory stateFactory, StateUpdater updater) partitionPersist
(StateFactory stateFactory, StateUpdater updater, Fields functionFields) partitionPersist
(StateFactory stateFactory, Fields inputFields, StateUpdater updater) partitionPersist
(StateFactory stateFactory, Fields inputFields, StateUpdater updater, Fields functionFields) partitionPersist
(StateSpec stateSpec, StateUpdater updater) partitionPersist
(StateSpec stateSpec, StateUpdater updater, Fields functionFields) partitionPersist
(StateSpec stateSpec, Fields inputFields, StateUpdater updater) partitionPersist
(StateSpec stateSpec, Fields inputFields, StateUpdater updater, Fields functionFields) Returns a stream consisting of the trident tuples of this stream, additionally performing the provided action on each trident tuple as they are consumed from the resulting stream.persistentAggregate
(StateFactory stateFactory, CombinerAggregator agg, Fields functionFields) persistentAggregate
(StateFactory stateFactory, ReducerAggregator agg, Fields functionFields) persistentAggregate
(StateFactory stateFactory, Fields inputFields, CombinerAggregator agg, Fields functionFields) persistentAggregate
(StateFactory stateFactory, Fields inputFields, ReducerAggregator agg, Fields functionFields) persistentAggregate
(StateSpec spec, CombinerAggregator agg, Fields functionFields) persistentAggregate
(StateSpec spec, ReducerAggregator agg, Fields functionFields) persistentAggregate
(StateSpec spec, Fields inputFields, CombinerAggregator agg, Fields functionFields) persistentAggregate
(StateSpec spec, Fields inputFields, ReducerAggregator agg, Fields functionFields) Filters out fields from a stream, resulting in a Stream containing only the fields specified by `keepFields`.setCPULoad
(Number load) Sets the CPU Load resource for the current operation.setMemoryLoad
(Number onHeap) Sets the Memory Load resources for the current operation. offHeap becomes default.setMemoryLoad
(Number onHeap, Number offHeap) Sets the Memory Load resources for the current operation.shuffle()
## Repartitioning Operation.slidingWindow
(int windowCount, int slideCount, WindowsStoreFactory windowStoreFactory, Fields inputFields, Aggregator aggregator, Fields functionFields) Returns a stream of tuples which are aggregated results of a sliding window with everywindowCount
of tuples and slides the window afterslideCount
.slidingWindow
(BaseWindowedBolt.Duration windowDuration, BaseWindowedBolt.Duration slidingInterval, WindowsStoreFactory windowStoreFactory, Fields inputFields, Aggregator aggregator, Fields functionFields) Returns a stream of tuples which are aggregated results of a window which slides at duration ofslidingInterval
and completes a window atwindowDuration
.stateQuery
(TridentState state, QueryFunction function, Fields functionFields) stateQuery
(TridentState state, Fields inputFields, QueryFunction function, Fields functionFields) toStream()
tumblingWindow
(int windowCount, WindowsStoreFactory windowStoreFactory, Fields inputFields, Aggregator aggregator, Fields functionFields) Returns a stream of tuples which are aggregated results of a tumbling window with everywindowCount
of tuples.tumblingWindow
(BaseWindowedBolt.Duration windowDuration, WindowsStoreFactory windowStoreFactory, Fields inputFields, Aggregator aggregator, Fields functionFields) Returns a stream of tuples which are aggregated results of a window that tumbles at duration ofwindowDuration
.window
(WindowConfig windowConfig, WindowsStoreFactory windowStoreFactory, Fields inputFields, Aggregator aggregator, Fields functionFields) Returns stream of aggregated results based on the given window configuration.window
(WindowConfig windowConfig, Fields inputFields, Aggregator aggregator, Fields functionFields) Returns a stream of aggregated results based on the given window configuration which uses inmemory windowing tuple store.
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Constructor Details
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Stream
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Method Details
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name
Applies a label to the stream. Naming a stream will append the label to the name of the bolt(s) created by Trident and will be visible in the Storm UI.- Parameters:
name
- - The label to apply to the stream
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parallelismHint
Applies a parallelism hint to a stream. -
setCPULoad
Sets the CPU Load resource for the current operation.- Specified by:
setCPULoad
in interfaceResourceDeclarer<Stream>
- Parameters:
load
- the amount of CPU- Returns:
- this for chaining
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setMemoryLoad
Sets the Memory Load resources for the current operation. offHeap becomes default.- Specified by:
setMemoryLoad
in interfaceResourceDeclarer<Stream>
- Parameters:
onHeap
- the amount of on heap memory- Returns:
- this for chaining
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setMemoryLoad
Sets the Memory Load resources for the current operation.- Specified by:
setMemoryLoad
in interfaceResourceDeclarer<Stream>
- Parameters:
onHeap
- the amount of on heap memoryoffHeap
- the amount of off heap memory- Returns:
- this for chaining
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project
Filters out fields from a stream, resulting in a Stream containing only the fields specified by `keepFields`.For example, if you had a Stream `mystream` containing the fields `["a", "b", "c","d"]`, calling"
```java mystream.project(new Fields("b", "d")) ```
would produce a stream containing only the fields `["b", "d"]`.
- Parameters:
keepFields
- The fields in the Stream to keep
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groupBy
## Grouping Operation. -
partitionBy
## Repartitioning Operation. -
partition
## Repartitioning Operation. -
partition
## Repartitioning Operation.This method takes in a custom partitioning function that implements
CustomStreamGrouping
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shuffle
## Repartitioning Operation.Use random round robin algorithm to evenly redistribute tuples across all target partitions.
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localOrShuffle
## Repartitioning Operation.Use random round robin algorithm to evenly redistribute tuples across all target partitions, with a preference for local tasks.
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global
## Repartitioning Operation.All tuples are sent to the same partition. The same partition is chosen for all batches in the stream.
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batchGlobal
## Repartitioning Operation.All tuples in the batch are sent to the same partition. Different batches in the stream may go to different partitions.
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broadcast
## Repartitioning Operation.Every tuple is replicated to all target partitions. This can useful during DRPC – for example, if you need to do a stateQuery on every partition of data.
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identityPartition
## Repartitioning Operation. -
applyAssembly
Applies an `Assembly` to this `Stream`.- See Also:
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each
- Specified by:
each
in interfaceIAggregatableStream
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each
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each
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partitionAggregate
- Specified by:
partitionAggregate
in interfaceIAggregatableStream
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partitionAggregate
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partitionAggregate
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partitionAggregate
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partitionAggregate
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partitionAggregate
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stateQuery
public Stream stateQuery(TridentState state, Fields inputFields, QueryFunction function, Fields functionFields) -
stateQuery
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partitionPersist
public TridentState partitionPersist(StateFactory stateFactory, Fields inputFields, StateUpdater updater, Fields functionFields) -
partitionPersist
public TridentState partitionPersist(StateSpec stateSpec, Fields inputFields, StateUpdater updater, Fields functionFields) -
partitionPersist
public TridentState partitionPersist(StateFactory stateFactory, Fields inputFields, StateUpdater updater) -
partitionPersist
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partitionPersist
public TridentState partitionPersist(StateFactory stateFactory, StateUpdater updater, Fields functionFields) -
partitionPersist
public TridentState partitionPersist(StateSpec stateSpec, StateUpdater updater, Fields functionFields) -
partitionPersist
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partitionPersist
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filter
Returns a stream consisting of the elements of this stream that match the given filter.- Parameters:
filter
- the filter to apply to each trident tuple to determine if it should be included.- Returns:
- the new stream
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filter
Returns a stream consisting of the elements of this stream that match the given filter.- Parameters:
inputFields
- the fields of the input trident tuple to be selected.filter
- the filter to apply to each trident tuple to determine if it should be included.- Returns:
- the new stream
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map
Returns a stream consisting of the result of applying the given mapping function to the values of this stream.- Parameters:
function
- a mapping function to be applied to each value in this stream.- Returns:
- the new stream
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map
Returns a stream consisting of the result of applying the given mapping function to the values of this stream. This method replaces old output fields with new output fields, achieving T -> V conversion.- Parameters:
function
- a mapping function to be applied to each value in this stream.outputFields
- new output fields- Returns:
- the new stream
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flatMap
Returns a stream consisting of the results of replacing each value of this stream with the contents produced by applying the provided mapping function to each value. This has the effect of applying a one-to-many transformation to the values of the stream, and then flattening the resulting elements into a new stream.- Parameters:
function
- a mapping function to be applied to each value in this stream which produces new values.- Returns:
- the new stream
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flatMap
Returns a stream consisting of the results of replacing each value of this stream with the contents produced by applying the provided mapping function to each value. This has the effect of applying a one-to-many transformation to the values of the stream, and then flattening the resulting elements into a new stream. This method replaces old output fields with new output fields, achieving T -> V conversion.- Parameters:
function
- a mapping function to be applied to each value in this stream which produces new values.outputFields
- new output fields- Returns:
- the new stream
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peek
Returns a stream consisting of the trident tuples of this stream, additionally performing the provided action on each trident tuple as they are consumed from the resulting stream. This is mostly useful for debugging to see the tuples as they flow past a certain point in a pipeline.- Parameters:
action
- the action to perform on the trident tuple as they are consumed from the stream- Returns:
- the new stream
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chainedAgg
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minBy
This aggregator operation computes the minimum of tuples by the giveninputFieldName
and it is assumed that its value is an instance ofComparable
. If the value of tuple with fieldinputFieldName
is not an instance ofComparable
then it throwsClassCastException
- Parameters:
inputFieldName
- input field name- Returns:
- the new stream with this operation.
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minBy
This aggregator operation computes the minimum of tuples by the giveninputFieldName
in a stream by using the givencomparator
. If the value of tuple with fieldinputFieldName
is not an instance ofT
then it throwsClassCastException
- Parameters:
inputFieldName
- input field namecomparator
- comparator used in for finding minimum of two tuple values ofinputFieldName
.- Returns:
- the new stream with this operation.
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min
This aggregator operation computes the minimum of tuples in a stream by using the givencomparator
withTridentTuple
s.- Parameters:
comparator
- comparator used in for finding minimum of two tuple values.- Returns:
- the new stream with this operation.
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maxBy
This aggregator operation computes the maximum of tuples by the giveninputFieldName
and it is assumed that its value is an instance ofComparable
. If the value of tuple with fieldinputFieldName
is not an instance ofComparable
then it throwsClassCastException
- Parameters:
inputFieldName
- input field name- Returns:
- the new stream with this operation.
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maxBy
This aggregator operation computes the maximum of tuples by the giveninputFieldName
in a stream by using the givencomparator
. If the value of tuple with fieldinputFieldName
is not an instance ofT
then it throwsClassCastException
- Parameters:
inputFieldName
- input field namecomparator
- comparator used in for finding maximum of two tuple values ofinputFieldName
.- Returns:
- the new stream with this operation.
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max
This aggregator operation computes the maximum of tuples in a stream by using the givencomparator
withTridentTuple
s.- Parameters:
comparator
- comparator used in for finding maximum of two tuple values.- Returns:
- the new stream with this operation.
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aggregate
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aggregate
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aggregate
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aggregate
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aggregate
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aggregate
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tumblingWindow
public Stream tumblingWindow(int windowCount, WindowsStoreFactory windowStoreFactory, Fields inputFields, Aggregator aggregator, Fields functionFields) Returns a stream of tuples which are aggregated results of a tumbling window with everywindowCount
of tuples.- Parameters:
windowCount
- represents number of tuples in the windowwindowStoreFactory
- intermediary tuple store for storing windowing tuplesinputFields
- projected fields for aggregatoraggregator
- aggregator to run on the window of tuples to compute the result and emit to the stream.functionFields
- fields of values to emit with aggregation.- Returns:
- the new stream with this operation.
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tumblingWindow
public Stream tumblingWindow(BaseWindowedBolt.Duration windowDuration, WindowsStoreFactory windowStoreFactory, Fields inputFields, Aggregator aggregator, Fields functionFields) Returns a stream of tuples which are aggregated results of a window that tumbles at duration ofwindowDuration
.- Parameters:
windowDuration
- represents tumbling window duration configurationwindowStoreFactory
- intermediary tuple store for storing windowing tuplesinputFields
- projected fields for aggregatoraggregator
- aggregator to run on the window of tuples to compute the result and emit to the stream.functionFields
- fields of values to emit with aggregation.- Returns:
- the new stream with this operation.
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slidingWindow
public Stream slidingWindow(int windowCount, int slideCount, WindowsStoreFactory windowStoreFactory, Fields inputFields, Aggregator aggregator, Fields functionFields) Returns a stream of tuples which are aggregated results of a sliding window with everywindowCount
of tuples and slides the window afterslideCount
.- Parameters:
windowCount
- represents tuples count of a windowslideCount
- the number of tuples after which the window slideswindowStoreFactory
- intermediary tuple store for storing windowing tuplesinputFields
- projected fields for aggregatoraggregator
- aggregator to run on the window of tuples to compute the result and emit to the stream.functionFields
- fields of values to emit with aggregation.- Returns:
- the new stream with this operation.
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slidingWindow
public Stream slidingWindow(BaseWindowedBolt.Duration windowDuration, BaseWindowedBolt.Duration slidingInterval, WindowsStoreFactory windowStoreFactory, Fields inputFields, Aggregator aggregator, Fields functionFields) Returns a stream of tuples which are aggregated results of a window which slides at duration ofslidingInterval
and completes a window atwindowDuration
.- Parameters:
windowDuration
- represents window duration configurationslidingInterval
- the time duration after which the window slideswindowStoreFactory
- intermediary tuple store for storing windowing tuplesinputFields
- projected fields for aggregatoraggregator
- aggregator to run on the window of tuples to compute the result and emit to the stream.functionFields
- fields of values to emit with aggregation.- Returns:
- the new stream with this operation.
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window
public Stream window(WindowConfig windowConfig, Fields inputFields, Aggregator aggregator, Fields functionFields) Returns a stream of aggregated results based on the given window configuration which uses inmemory windowing tuple store.- Parameters:
windowConfig
- window configuration like window length and slide length.inputFields
- input fieldsaggregator
- aggregator to run on the window of tuples to compute the result and emit to the stream.functionFields
- fields of values to emit with aggregation.- Returns:
- the new stream with this operation.
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window
public Stream window(WindowConfig windowConfig, WindowsStoreFactory windowStoreFactory, Fields inputFields, Aggregator aggregator, Fields functionFields) Returns stream of aggregated results based on the given window configuration.- Parameters:
windowConfig
- window configuration like window length and slide length.windowStoreFactory
- intermediary tuple store for storing tuples for windowinginputFields
- input fieldsaggregator
- aggregator to run on the window of tuples to compute the result and emit to the stream.functionFields
- fields of values to emit with aggregation.- Returns:
- the new stream with this operation.
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persistentAggregate
public TridentState persistentAggregate(StateFactory stateFactory, CombinerAggregator agg, Fields functionFields) -
persistentAggregate
public TridentState persistentAggregate(StateSpec spec, CombinerAggregator agg, Fields functionFields) -
persistentAggregate
public TridentState persistentAggregate(StateFactory stateFactory, Fields inputFields, CombinerAggregator agg, Fields functionFields) -
persistentAggregate
public TridentState persistentAggregate(StateSpec spec, Fields inputFields, CombinerAggregator agg, Fields functionFields) -
persistentAggregate
public TridentState persistentAggregate(StateFactory stateFactory, ReducerAggregator agg, Fields functionFields) -
persistentAggregate
public TridentState persistentAggregate(StateSpec spec, ReducerAggregator agg, Fields functionFields) -
persistentAggregate
public TridentState persistentAggregate(StateFactory stateFactory, Fields inputFields, ReducerAggregator agg, Fields functionFields) -
persistentAggregate
public TridentState persistentAggregate(StateSpec spec, Fields inputFields, ReducerAggregator agg, Fields functionFields) -
toStream
- Specified by:
toStream
in interfaceIAggregatableStream
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getName
Returns the label applied to the stream.- Returns:
- the label applied to the stream.
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getOutputFields
- Specified by:
getOutputFields
in interfaceIAggregatableStream
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