org.apache.beam.sdk.transforms

Class ParDo.SingleOutput<InputT,OutputT>

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PCollection<? extends InputT>,PCollection<OutputT>>

org.apache.beam.sdk.transforms.ParDo.SingleOutput<InputT,OutputT>

Type Parameters:

InputT - the type of the (main) input PCollection elements

OutputT - the type of the (main) output PCollection elements

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

Enclosing class:

ParDo

public static class ParDo.SingleOutput<InputT,OutputT>
extends PTransform<PCollection<? extends InputT>,PCollection<OutputT>>

A PTransform that, when applied to a PCollection<InputT>, invokes a user-specified DoFn<InputT, OutputT> on all its elements, with all its outputs collected into an output PCollection<OutputT>.

A multi-output form of this transform can be created with withOutputTags(org.apache.beam.sdk.values.TupleTag<OutputT>, org.apache.beam.sdk.values.TupleTagList).

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<OutputT>	expand(PCollection<? extends InputT> input) Override this method to specify how this PTransform should be expanded on the given InputT.
java.util.Map<TupleTag<?>,PValue>	getAdditionalInputs() Returns the side inputs of this ParDo, tagged with the tag of the PCollectionView.
protected Coder<OutputT>	getDefaultOutputCoder(PCollection<? extends InputT> input) Returns the default Coder to use for the output of this single-output PTransform when applied to the given input.
DoFn<InputT,OutputT>	getFn()
protected java.lang.String	getKindString() Returns the name to use by default for this PTransform (not including the names of any enclosing PTransforms).
java.util.List<PCollectionView<?>>	getSideInputs()
void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.
ParDo.MultiOutput<InputT,OutputT>	withOutputTags(TupleTag<OutputT> mainOutputTag, TupleTagList additionalOutputTags) Returns a new multi-output ParDo PTransform that's like this PTransform but with the specified output tags.
ParDo.SingleOutput<InputT,OutputT>	withSideInputs(java.lang.Iterable<? extends PCollectionView<?>> sideInputs) Returns a new ParDo PTransform that's like this PTransform but with the specified additional side inputs.
ParDo.SingleOutput<InputT,OutputT>	withSideInputs(PCollectionView<?>... sideInputs) Returns a new ParDo PTransform that's like this PTransform but with the specified additional side inputs.

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

getDefaultOutputCoder, getDefaultOutputCoder, getName, toString, validate

Methods inherited from class java.lang.Object

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

Method Detail

withSideInputs

public ParDo.SingleOutput<InputT,OutputT> withSideInputs(PCollectionView<?>... sideInputs)

Returns a new ParDo PTransform that's like this PTransform but with the specified additional side inputs. Does not modify this PTransform.

See the discussion of Side Inputs above for more explanation.

withSideInputs

public ParDo.SingleOutput<InputT,OutputT> withSideInputs(java.lang.Iterable<? extends PCollectionView<?>> sideInputs)

Returns a new ParDo PTransform that's like this PTransform but with the specified additional side inputs. Does not modify this PTransform.

See the discussion of Side Inputs above for more explanation.

withOutputTags

public ParDo.MultiOutput<InputT,OutputT> withOutputTags(TupleTag<OutputT> mainOutputTag,
                                                        TupleTagList additionalOutputTags)

Returns a new multi-output ParDo PTransform that's like this PTransform but with the specified output tags. Does not modify this PTransform.

See the discussion of Additional Outputs above for more explanation.

expand

public PCollection<OutputT> expand(PCollection<? extends InputT> input)

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<PCollection<? extends InputT>,PCollection<OutputT>>

getDefaultOutputCoder

protected Coder<OutputT> getDefaultOutputCoder(PCollection<? extends InputT> 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<PCollection<? extends InputT>,PCollection<OutputT>>

Throws:

CannotProvideCoderException - if none can be inferred.

getKindString

protected java.lang.String getKindString()

Description copied from class: PTransform

Returns the name to use by default for this PTransform (not including the names of any enclosing PTransforms).

By default, returns the base name of this PTransform's class.

The caller is responsible for ensuring that names of applied PTransforms are unique, e.g., by adding a uniquifying suffix when needed.

Overrides:

getKindString in class PTransform<PCollection<? extends InputT>,PCollection<OutputT>>

populateDisplayData

public void populateDisplayData(DisplayData.Builder builder)

Register display data for the given transform or component.

populateDisplayData(DisplayData.Builder) is invoked by Pipeline runners to collect display data via DisplayData.from(HasDisplayData). Implementations may call super.populateDisplayData(builder) in order to register display data in the current namespace, but should otherwise use subcomponent.populateDisplayData(builder) to use the namespace of the subcomponent.

By default, does not register any display data. Implementors may override this method to provide their own display data.

ParDo registers its internal DoFn as a subcomponent for display data. DoFn implementations can register display data by overriding DoFn.populateDisplayData(org.apache.beam.sdk.transforms.display.DisplayData.Builder).

Specified by:

populateDisplayData in interface HasDisplayData

Overrides:

populateDisplayData in class PTransform<PCollection<? extends InputT>,PCollection<OutputT>>

Parameters:

builder - The builder to populate with display data.

See Also:

HasDisplayData

getFn

public DoFn<InputT,OutputT> getFn()

getSideInputs

public java.util.List<PCollectionView<?>> getSideInputs()

getAdditionalInputs

public java.util.Map<TupleTag<?>,PValue> getAdditionalInputs()

Returns the side inputs of this ParDo, tagged with the tag of the PCollectionView. The values of the returned map will be equal to the result of getSideInputs().

Overrides:

getAdditionalInputs in class PTransform<PCollection<? extends InputT>,PCollection<OutputT>>