com.google.cloud.dataflow.sdk.io

Class TextIO.Write.Bound<T>

java.lang.Object

com.google.cloud.dataflow.sdk.transforms.PTransform<PCollection<T>,PDone>

com.google.cloud.dataflow.sdk.io.TextIO.Write.Bound<T>

Type Parameters:

T - the type of the elements of the input PCollection

All Implemented Interfaces:

java.io.Serializable

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 com.google.cloud.dataflow.sdk.transforms.PTransform

name

Method Summary

Methods

Modifier and Type	Method and Description
PDone	apply(PCollection<T> input) Applies this PTransform on the given Input, and returns its Output.
Coder<T>	getCoder()
protected Coder<java.lang.Void>	getDefaultOutputCoder() Returns the default Coder to use for the output of this single-output PTransform, or null if none can be inferred.
java.lang.String	getFilenamePrefix()
java.lang.String	getFilenameSuffix()
protected java.lang.String	getKindString() Returns a string describing what kind of PTransform this is.
int	getNumShards()
java.lang.String	getShardNameTemplate() Returns the current shard name template string.
java.lang.String	getShardTemplate()
TextIO.Write.Bound<T>	named(java.lang.String name) Returns a new TextIO.Write PTransform that's like this one but with the given step name.
TextIO.Write.Bound<T>	to(java.lang.String filenamePrefix) Returns a new TextIO.Write PTransform that's like this one but that writes to the file(s) with the given filename prefix.
<T1> TextIO.Write.Bound<T1>	withCoder(Coder<T1> coder) Returns a new TextIO.Write PTransform that's like this one but that uses the given Coder<T1> to encode each of the elements of the input PCollection<T1> into an output text line.
TextIO.Write.Bound<T>	withNumShards(int numShards) Returns a new TextIO.Write PTransform that's like this one but that uses the provided shard count.
TextIO.Write.Bound<T>	withoutSharding() Returns a new TextIO.Write PTransform that's like this one but that forces a single file as output.
TextIO.Write.Bound<T>	withShardNameTemplate(java.lang.String shardTemplate) Returns a new TextIO.Write PTransform that's like this one but that uses the given shard name template.
TextIO.Write.Bound<T>	withSuffix(java.lang.String nameExtension) Returns a new TextIO.Write PTransform that's like this one but that writes to the file(s) with the given filename suffix.

Methods inherited from class com.google.cloud.dataflow.sdk.transforms.PTransform

finishSpecifying, getCoderRegistry, getDefaultName, getDefaultOutputCoder, getInput, getName, getOutput, getPipeline, setName, setPipeline, toString, withName

Methods inherited from class java.lang.Object

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

Method Detail

named

public TextIO.Write.Bound<T> named(java.lang.String name)

Returns a new TextIO.Write PTransform that's like this one but with the given step name. Does not modify this object.

to

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

Returns a new TextIO.Write PTransform 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(java.lang.String nameExtension)

Returns a new TextIO.Write PTransform 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 new TextIO.Write PTransform 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(java.lang.String shardTemplate)

Returns a new TextIO.Write PTransform 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 new TextIO.Write PTransform that's like this one but that forces a single file as output.

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

Does not modify this object.

withCoder

public <T1> TextIO.Write.Bound<T1> withCoder(Coder<T1> coder)

Returns a new TextIO.Write PTransform that's like this one but that uses the given Coder<T1> to encode each of the elements of the input PCollection<T1> into an output text line. Does not modify this object.

Type Parameters:

T1 - the type of the elements of the input PCollection

apply

public PDone apply(PCollection<T> input)

Description copied from class: PTransform

Applies this PTransform on the given Input, 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).

The default implementation throws an exception. A derived class must either implement apply, or else each runner must supply a custom implementation via PipelineRunner.apply(com.google.cloud.dataflow.sdk.transforms.PTransform<Input, Output>, Input).

Overrides:

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

getShardNameTemplate

public java.lang.String getShardNameTemplate()

Returns the current shard name template string.

getDefaultOutputCoder

protected Coder<java.lang.Void> getDefaultOutputCoder()

Description copied from class: PTransform

Returns the default Coder to use for the output of this single-output PTransform, or null if none can be inferred.

By default, returns null.

Overrides:

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

getKindString

protected java.lang.String getKindString()

Description copied from class: PTransform

Returns a string describing what kind of PTransform this is.

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

Overrides:

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

getFilenamePrefix

public java.lang.String getFilenamePrefix()

getShardTemplate

public java.lang.String getShardTemplate()

getNumShards

public int getNumShards()

getFilenameSuffix

public java.lang.String getFilenameSuffix()

getCoder

public Coder<T> getCoder()