org.apache.beam.sdk.io

Class TextIO.Write.Bound<T>

java.lang.Object

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

org.apache.beam.sdk.io.TextIO.Write.Bound<T>

Type Parameters:

T - the type of the elements of the input PCollection

All Implemented Interfaces:

Serializable, HasDisplayData

Enclosing class:

TextIO.Write

public static class TextIO.Write.Bound<T>
extends PTransform<PCollection<T>,PDone>

A PTransform that writes a bounded PCollection to a text file (or multiple text files matching a sharding pattern), with each PCollection element being encoded into its own line.

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
PDone	apply(PCollection<T> input) Applies this PTransform on the given InputT, and returns its Output.
Coder<T>	getCoder()
protected Coder<Void>	getDefaultOutputCoder() Returns the default Coder to use for the output of this single-output PTransform.
String	getFilenamePrefix()
String	getFilenameSuffix()
int	getNumShards()
String	getShardNameTemplate() Returns the current shard name template string.
String	getShardTemplate()
boolean	needsValidation()
void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.
TextIO.Write.Bound<T>	to(String filenamePrefix) Returns a transform for writing to text files that's like this one but that writes to the file(s) with the given filename prefix.
<X> TextIO.Write.Bound<X>	withCoder(Coder<X> coder) Returns a transform for writing to text files that's like this one but that uses the given Coder to encode each of the elements of the input PCollection into an output text line.
TextIO.Write.Bound<T>	withNumShards(int numShards) Returns a transform for writing to text files that's like this one but that uses the provided shard count.
TextIO.Write.Bound<T>	withoutSharding() Returns a transform for writing to text files that's like this one but that forces a single file as output.
TextIO.Write.Bound<T>	withoutValidation() Returns a transform for writing to text files that's like this one but that has GCS output path validation on pipeline creation disabled.
TextIO.Write.Bound<T>	withShardNameTemplate(String shardTemplate) Returns a transform for writing to text files that's like this one but that uses the given shard name template.
TextIO.Write.Bound<T>	withSuffix(String nameExtension) Returns a transform for writing to text files that that's like this one but that writes to the file(s) with the given filename suffix.

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

getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, toString, validate

Methods inherited from class java.lang.Object

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

Method Detail

to

public TextIO.Write.Bound<T> to(String filenamePrefix)

Returns a transform for writing to text files that's like this one but that writes to the file(s) with the given filename prefix.

See Write.to(String) for more information.

Does not modify this object.

withSuffix

public TextIO.Write.Bound<T> withSuffix(String nameExtension)

Returns a transform for writing to text files that that's like this one but that writes to the file(s) with the given filename suffix.

Does not modify this object.

See Also:

ShardNameTemplate

withNumShards

public TextIO.Write.Bound<T> withNumShards(int numShards)

Returns a transform for writing to text files that's like this one but that uses the provided shard count.

Constraining the number of shards is likely to reduce the performance of a pipeline. Setting this value is not recommended unless you require a specific number of output files.

Does not modify this object.

Parameters:

numShards - the number of shards to use, or 0 to let the system decide.

See Also:

ShardNameTemplate

withShardNameTemplate

public TextIO.Write.Bound<T> withShardNameTemplate(String shardTemplate)

Returns a transform for writing to text files that's like this one but that uses the given shard name template.

Does not modify this object.

See Also:

ShardNameTemplate

withoutSharding

public TextIO.Write.Bound<T> withoutSharding()

Returns a transform for writing to text files that's like this one but that forces a single file as output.

Constraining the number of shards is likely to reduce the performance of a pipeline. Using this setting is not recommended unless you truly require a single output file.

This is a shortcut for .withNumShards(1).withShardNameTemplate("")

Does not modify this object.

withCoder

public <X> TextIO.Write.Bound<X> withCoder(Coder<X> coder)

Returns a transform for writing to text files that's like this one but that uses the given Coder to encode each of the elements of the input PCollection into an output text line. Does not modify this object.

Type Parameters:

X - the type of the elements of the input PCollection

withoutValidation

public TextIO.Write.Bound<T> withoutValidation()

Returns a transform for writing to text files that's like this one but that has GCS output path validation on pipeline creation disabled.

This can be useful in the case where the GCS output location does not exist at the pipeline creation time, but is expected to be available at execution time.

Does not modify this object.

apply

public PDone apply(PCollection<T> input)

Description copied from class: PTransform

Applies this PTransform on the given InputT, and returns its Output.

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:

apply in class PTransform<PCollection<T>,PDone>

populateDisplayData

public void populateDisplayData(DisplayData.Builder builder)

Description copied from class: PTransform

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.

Specified by:

populateDisplayData in interface HasDisplayData

Overrides:

populateDisplayData in class PTransform<PCollection<T>,PDone>

Parameters:

builder - The builder to populate with display data.

See Also:

HasDisplayData

getShardNameTemplate

public String getShardNameTemplate()

Returns the current shard name template string.

getDefaultOutputCoder

protected Coder<Void> getDefaultOutputCoder()

Description copied from class: PTransform

Returns the default Coder to use for the output of this single-output PTransform.

By default, always throws

Overrides:

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

getFilenamePrefix

public String getFilenamePrefix()

getShardTemplate

public String getShardTemplate()

getNumShards

public int getNumShards()

getFilenameSuffix

public String getFilenameSuffix()

getCoder

public Coder<T> getCoder()

needsValidation

public boolean needsValidation()