org.apache.beam.sdk.transforms

Class Flatten.PCollections<T>

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PCollectionList<T>,PCollection<T>>

org.apache.beam.sdk.transforms.Flatten.PCollections<T>

Type Parameters:

T - the type of the elements in the input and output PCollections.

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

Enclosing class:

Flatten

public static class Flatten.PCollections<T>
extends PTransform<PCollectionList<T>,PCollection<T>>

A PTransform that flattens a PCollectionList into a PCollection containing all the elements of all the PCollections in its input. Implements Flatten.pCollections().

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.beam.sdk.transforms.PTransform

name

Method Summary

Modifier and Type	Method and Description
PCollection<T>	expand(PCollectionList<T> inputs) Override this method to specify how this PTransform should be expanded on the given InputT.
protected Coder<?>	getDefaultOutputCoder(PCollectionList<T> input) Returns the default Coder to use for the output of this single-output PTransform when applied to the given input.

Methods inherited from class org.apache.beam.sdk.transforms.PTransform

getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, populateDisplayData, toString, validate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

expand

public PCollection<T> expand(PCollectionList<T> inputs)

Description copied from class: PTransform

Override this method to specify how this PTransform should be expanded on the given InputT.

NOTE: This method should not be called directly. Instead apply the PTransform should be applied to the InputT using the apply method.

Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).

Specified by:

expand in class PTransform<PCollectionList<T>,PCollection<T>>

getDefaultOutputCoder

protected Coder<?> getDefaultOutputCoder(PCollectionList<T> input)
                                  throws CannotProvideCoderException

Description copied from class: PTransform

Returns the default Coder to use for the output of this single-output PTransform when applied to the given input.

By default, always throws.

Overrides:

getDefaultOutputCoder in class PTransform<PCollectionList<T>,PCollection<T>>

Throws:

CannotProvideCoderException - if none can be inferred.