Package org.apache.beam.sdk.io

Class TextIO.TypedWrite<UserT,DestinationT>

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PCollection<UserT>,WriteFilesResult<DestinationT>>

org.apache.beam.sdk.io.TextIO.TypedWrite<UserT,DestinationT>

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

Enclosing class:

TextIO

public abstract static class TextIO.TypedWrite<UserT,DestinationT>
extends PTransform<PCollection<UserT>,WriteFilesResult<DestinationT>>

Implementation of TextIO.write().

See Also:

Serialized Form

Field Summary

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

name, resourceHints

Constructor Summary

Constructors

Constructor	Description
TypedWrite()

Method Summary

Modifier and Type	Method	Description
WriteFilesResult<DestinationT>	expand(PCollection<UserT> input)	Override this method to specify how this PTransform should be expanded on the given InputT.
void	populateDisplayData(DisplayData.Builder builder)	Register display data for the given transform or component.
TextIO.TypedWrite<UserT,DestinationT>	skipIfEmpty()	Don't write any output files if the PCollection is empty.
TextIO.TypedWrite<UserT,DestinationT>	to(java.lang.String filenamePrefix)	Writes to text files with the given prefix.
<NewDestinationT> TextIO.TypedWrite<UserT,NewDestinationT>	to(FileBasedSink.DynamicDestinations<UserT,NewDestinationT,java.lang.String> dynamicDestinations)	Deprecated. Use FileIO.write() or FileIO.writeDynamic() with TextIO.sink() instead.
TextIO.TypedWrite<UserT,DestinationT>	to(FileBasedSink.FilenamePolicy filenamePolicy)	Writes to files named according to the given FileBasedSink.FilenamePolicy.
TextIO.TypedWrite<UserT,DestinationT>	to(ResourceId filenamePrefix)	Like to(String).
TextIO.TypedWrite<UserT,DestinationT>	to(ValueProvider<java.lang.String> outputPrefix)	Like to(String).
TextIO.TypedWrite<UserT,DefaultFilenamePolicy.Params>	to(SerializableFunction<UserT,DefaultFilenamePolicy.Params> destinationFunction, DefaultFilenamePolicy.Params emptyDestination)	Deprecated. Use FileIO.write() or FileIO.writeDynamic() with TextIO.sink() instead.
TextIO.TypedWrite<UserT,DestinationT>	toResource(ValueProvider<ResourceId> filenamePrefix)	Like to(ResourceId).
TextIO.TypedWrite<UserT,DestinationT>	withCompression(Compression compression)	Returns a transform for writing to text files like this one but that compresses output using the given Compression.
TextIO.TypedWrite<UserT,DestinationT>	withDelimiter(char[] delimiter)	Specifies the delimiter after each string written.
TextIO.TypedWrite<UserT,DestinationT>	withFooter(@Nullable java.lang.String footer)	Adds a footer string to each file.
TextIO.TypedWrite<UserT,DestinationT>	withFormatFunction(@Nullable SerializableFunction<UserT,java.lang.String> formatFunction)	Deprecated. Use FileIO.write() or FileIO.writeDynamic() with TextIO.sink() instead.
TextIO.TypedWrite<UserT,DestinationT>	withHeader(@Nullable java.lang.String header)	Adds a header string to each file.
TextIO.TypedWrite<UserT,DestinationT>	withNoSpilling()	See WriteFiles.withNoSpilling().
TextIO.TypedWrite<UserT,DestinationT>	withNumShards(int numShards)	Configures the number of output shards produced overall (when using unwindowed writes) or per-window (when using windowed writes).
TextIO.TypedWrite<UserT,DestinationT>	withNumShards(@Nullable ValueProvider<java.lang.Integer> numShards)	Like withNumShards(int).
TextIO.TypedWrite<UserT,DestinationT>	withoutSharding()	Forces a single file as output and empty shard name template.
TextIO.TypedWrite<UserT,DestinationT>	withShardNameTemplate(java.lang.String shardTemplate)	Uses the given ShardNameTemplate for naming output files.
TextIO.TypedWrite<UserT,DestinationT>	withSuffix(java.lang.String filenameSuffix)	Configures the filename suffix for written files.
TextIO.TypedWrite<UserT,DestinationT>	withTempDirectory(ResourceId tempDirectory)	Set the base directory used to generate temporary files.
TextIO.TypedWrite<UserT,DestinationT>	withTempDirectory(ValueProvider<ResourceId> tempDirectory)	Set the base directory used to generate temporary files.
TextIO.TypedWrite<UserT,DestinationT>	withWindowedWrites()	Preserves windowing of input elements and writes them to files based on the element's window.
TextIO.TypedWrite<UserT,DestinationT>	withWritableByteChannelFactory(FileBasedSink.WritableByteChannelFactory writableByteChannelFactory)	Returns a transform for writing to text files like this one but that has the given FileBasedSink.WritableByteChannelFactory to be used by the FileBasedSink during output.

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

compose, compose, getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, getResourceHints, setResourceHints, toString, validate, validate

Methods inherited from class java.lang.Object

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

Constructor Detail

TypedWrite

public TypedWrite()

Method Detail

to

public TextIO.TypedWrite<UserT,DestinationT> to(java.lang.String filenamePrefix)

Writes to text files with the given prefix. The given prefix can reference any FileSystem on the classpath. This prefix is used by the DefaultFilenamePolicy to generate filenames.

By default, a DefaultFilenamePolicy will be used built using the specified prefix to define the base output directory and file prefix, a shard identifier (see withNumShards(int)), and a common suffix (if supplied using withSuffix(String)).

This default policy can be overridden using to(FilenamePolicy), in which case withShardNameTemplate(String) and withSuffix(String) should not be set. Custom filename policies do not automatically see this prefix - you should explicitly pass the prefix into your FileBasedSink.FilenamePolicy object if you need this.

If withTempDirectory(org.apache.beam.sdk.options.ValueProvider<org.apache.beam.sdk.io.fs.ResourceId>) has not been called, this filename prefix will be used to infer a directory for temporary files.

to

@Experimental(FILESYSTEM)
public TextIO.TypedWrite<UserT,DestinationT> to(ResourceId filenamePrefix)

Like to(String).

to

public TextIO.TypedWrite<UserT,DestinationT> to(ValueProvider<java.lang.String> outputPrefix)

Like to(String).

to

public TextIO.TypedWrite<UserT,DestinationT> to(FileBasedSink.FilenamePolicy filenamePolicy)

Writes to files named according to the given FileBasedSink.FilenamePolicy. A directory for temporary files must be specified using withTempDirectory(org.apache.beam.sdk.options.ValueProvider<org.apache.beam.sdk.io.fs.ResourceId>).

to

@Deprecated
public <NewDestinationT> TextIO.TypedWrite<UserT,NewDestinationT> to(FileBasedSink.DynamicDestinations<UserT,NewDestinationT,java.lang.String> dynamicDestinations)

Deprecated.

Use FileIO.write() or FileIO.writeDynamic() with TextIO.sink() instead.

Use a FileBasedSink.DynamicDestinations object to vend FileBasedSink.FilenamePolicy objects. These objects can examine the input record when creating a FileBasedSink.FilenamePolicy. A directory for temporary files must be specified using withTempDirectory(org.apache.beam.sdk.options.ValueProvider<org.apache.beam.sdk.io.fs.ResourceId>).

to

@Deprecated
public TextIO.TypedWrite<UserT,DefaultFilenamePolicy.Params> to(SerializableFunction<UserT,DefaultFilenamePolicy.Params> destinationFunction,
                                                                      DefaultFilenamePolicy.Params emptyDestination)

Deprecated.

Use FileIO.write() or FileIO.writeDynamic() with TextIO.sink() instead.

Write to dynamic destinations using the default filename policy. The destinationFunction maps the input record to a DefaultFilenamePolicy.Params object that specifies where the records should be written (base filename, file suffix, and shard template). The emptyDestination parameter specified where empty files should be written for when the written PCollection is empty.

toResource

@Experimental(FILESYSTEM)
public TextIO.TypedWrite<UserT,DestinationT> toResource(ValueProvider<ResourceId> filenamePrefix)

Like to(ResourceId).

withFormatFunction

@Deprecated
public TextIO.TypedWrite<UserT,DestinationT> withFormatFunction(@Nullable SerializableFunction<UserT,java.lang.String> formatFunction)

Deprecated.

Use FileIO.write() or FileIO.writeDynamic() with TextIO.sink() instead.

Specifies a format function to convert TextIO.TypedWrite to the output type. If to(DynamicDestinations) is used, FileBasedSink.DynamicDestinations.formatRecord(Object) must be used instead.

withTempDirectory

@Experimental(FILESYSTEM)
public TextIO.TypedWrite<UserT,DestinationT> withTempDirectory(ValueProvider<ResourceId> tempDirectory)

Set the base directory used to generate temporary files.

withTempDirectory

@Experimental(FILESYSTEM)
public TextIO.TypedWrite<UserT,DestinationT> withTempDirectory(ResourceId tempDirectory)

Set the base directory used to generate temporary files.

withShardNameTemplate

public TextIO.TypedWrite<UserT,DestinationT> withShardNameTemplate(java.lang.String shardTemplate)

Uses the given ShardNameTemplate for naming output files. This option may only be used when using one of the default filename-prefix to() overrides - i.e. not when using either to(FilenamePolicy) or to(DynamicDestinations).

See DefaultFilenamePolicy for how the prefix, shard name template, and suffix are used.

withSuffix

public TextIO.TypedWrite<UserT,DestinationT> withSuffix(java.lang.String filenameSuffix)

Configures the filename suffix for written files. This option may only be used when using one of the default filename-prefix to() overrides - i.e. not when using either to(FilenamePolicy) or to(DynamicDestinations).

See DefaultFilenamePolicy for how the prefix, shard name template, and suffix are used.

withNumShards

public TextIO.TypedWrite<UserT,DestinationT> withNumShards(int numShards)

Configures the number of output shards produced overall (when using unwindowed writes) or per-window (when using windowed writes).

For unwindowed writes, 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.

Parameters:

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

withNumShards

public TextIO.TypedWrite<UserT,DestinationT> withNumShards(@Nullable ValueProvider<java.lang.Integer> numShards)

Like withNumShards(int). Specifying null means runner-determined sharding.

withoutSharding

public TextIO.TypedWrite<UserT,DestinationT> withoutSharding()

Forces a single file as output and empty shard name template.

For unwindowed writes, 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.

This is equivalent to .withNumShards(1).withShardNameTemplate("")

withDelimiter

public TextIO.TypedWrite<UserT,DestinationT> withDelimiter(char[] delimiter)

Specifies the delimiter after each string written.

Defaults to '\n'.

withHeader

public TextIO.TypedWrite<UserT,DestinationT> withHeader(@Nullable java.lang.String header)

Adds a header string to each file. A newline after the header is added automatically.

A null value will clear any previously configured header.

withFooter

public TextIO.TypedWrite<UserT,DestinationT> withFooter(@Nullable java.lang.String footer)

Adds a footer string to each file. A newline after the footer is added automatically.

A null value will clear any previously configured footer.

withWritableByteChannelFactory

public TextIO.TypedWrite<UserT,DestinationT> withWritableByteChannelFactory(FileBasedSink.WritableByteChannelFactory writableByteChannelFactory)

Returns a transform for writing to text files like this one but that has the given FileBasedSink.WritableByteChannelFactory to be used by the FileBasedSink during output. The default is value is Compression.UNCOMPRESSED.

A null value will reset the value to the default value mentioned above.

withCompression

public TextIO.TypedWrite<UserT,DestinationT> withCompression(Compression compression)

Returns a transform for writing to text files like this one but that compresses output using the given Compression. The default value is Compression.UNCOMPRESSED.

withWindowedWrites

public TextIO.TypedWrite<UserT,DestinationT> withWindowedWrites()

Preserves windowing of input elements and writes them to files based on the element's window.

If using to(FileBasedSink.FilenamePolicy). Filenames will be generated using FileBasedSink.FilenamePolicy.windowedFilename(int, int, org.apache.beam.sdk.transforms.windowing.BoundedWindow, org.apache.beam.sdk.transforms.windowing.PaneInfo, org.apache.beam.sdk.io.FileBasedSink.OutputFileHints). See also WriteFiles.withWindowedWrites().

withNoSpilling

public TextIO.TypedWrite<UserT,DestinationT> withNoSpilling()

See WriteFiles.withNoSpilling().

skipIfEmpty

public TextIO.TypedWrite<UserT,DestinationT> skipIfEmpty()

Don't write any output files if the PCollection is empty.

expand

public WriteFilesResult<DestinationT> expand(PCollection<UserT> 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<UserT>,WriteFilesResult<DestinationT>>

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<UserT>,WriteFilesResult<DestinationT>>

Parameters:

builder - The builder to populate with display data.

See Also:

HasDisplayData