FileBasedSink (Google Cloud Dataflow SDK 1.9.1 API)

Google Cloud Dataflow SDK for Java, version 1.9.1

Warning: Dataflow SDK 1.x for Java is unsupported as of October 16, 2018. After August 12, 2020, you can use unsupported SDKs temporarily while you upgrade your pipelines. For more information, see Using an unsupported SDK.

For information on migrating from the 1.x SDK, see Migrating from Dataflow SDK 1.x for Java.

Note: If you are using Cloud Dataflow SDK version 2.x, see the Apache Beam API reference documentation.

com.google.cloud.dataflow.sdk.io

Class FileBasedSink<T>

• java.lang.Object
• • com.google.cloud.dataflow.sdk.io.Sink<T>
  • • com.google.cloud.dataflow.sdk.io.FileBasedSink<T>

• Type Parameters:

  T - the type of values written to the sink.

  All Implemented Interfaces:

  HasDisplayData, Serializable

  Direct Known Subclasses:

  XmlSink.Bound

  ---

  
  

  public abstract class FileBasedSink<T>
  extends Sink<T>

  Abstract Sink for file-based output. An implementation of FileBasedSink writes file-based output and defines the format of output files (how values are written, headers/footers, MIME type, etc.).

  At pipeline construction time, the methods of FileBasedSink are called to validate the sink and to create a Sink.WriteOperation that manages the process of writing to the sink.

  The process of writing to file-based sink is as follows:

  1. An optional subclass-defined initialization,
  2. a parallel write of bundles to temporary files, and finally,
  3. these temporary files are renamed with final output filenames.

  Supported file systems are those registered with IOChannelUtils.

  See Also:

  Serialized Form

• • Nested Class Summary

    Nested Classes 

    Modifier and Type	Class and Description
    static class	FileBasedSink.FileBasedWriteOperation<T> Abstract Sink.WriteOperation that manages the process of writing to a FileBasedSink.
    static class	FileBasedSink.FileBasedWriter<T> Abstract Sink.Writer that writes a bundle to a FileBasedSink.
    static class	FileBasedSink.FileResult Result of a single bundle write.

    • Nested classes/interfaces inherited from class com.google.cloud.dataflow.sdk.io.Sink

      Sink.WriteOperation<T,WriteT>, Sink.Writer<T,WriteT>

  • Field Summary

    Fields 

    Modifier and Type	Field and Description
    protected ValueProvider<String>	baseOutputFilename Base filename for final output files.
    protected String	extension The extension to be used for the final output files.
    protected String	fileNamingTemplate Naming template for output files.

  • Constructor Summary

    Constructors 

    Constructor and Description
    FileBasedSink(String baseOutputFilename, String extension) Construct a FileBasedSink with the given base output filename and extension.
    FileBasedSink(String baseOutputFilename, String extension, String fileNamingTemplate) Construct a FileBasedSink with the given base output filename, extension, and file naming template.
    FileBasedSink(ValueProvider<String> baseOutputFilename, String extension, String fileNamingTemplate) Construct a FileBasedSink with the given base output filename, extension, and file naming template.

  • Method Summary

    All Methods Instance Methods Abstract Methods Concrete Methods 

    Modifier and Type	Method and Description
    abstract FileBasedSink.FileBasedWriteOperation<T>	createWriteOperation(PipelineOptions options) Return a subclass of FileBasedSink.FileBasedWriteOperation that will manage the write to the sink.
    String	getBaseOutputFilename() Returns the base output filename for this file based sink.
    ValueProvider<String>	getBaseOutputFilenameProvider() Returns the base output filename for this file based sink.
    void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.
    void	validate(PipelineOptions options) Perform pipeline-construction-time validation.

    • Methods inherited from class java.lang.Object

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

• • Field Detail

    • baseOutputFilename

      protected final ValueProvider<String> baseOutputFilename

      Base filename for final output files.

    • extension

      protected final String extension

      The extension to be used for the final output files.

    • fileNamingTemplate

      protected final String fileNamingTemplate

      Naming template for output files. See ShardNameTemplate for a description of possible naming templates. Default is ShardNameTemplate.INDEX_OF_MAX.

  • Constructor Detail

    • FileBasedSink

      public FileBasedSink(String baseOutputFilename,
                           String extension)

      Construct a FileBasedSink with the given base output filename and extension.

    • FileBasedSink

      public FileBasedSink(String baseOutputFilename,
                           String extension,
                           String fileNamingTemplate)

      Construct a FileBasedSink with the given base output filename, extension, and file naming template.

      See ShardNameTemplate for a description of file naming templates.

    • FileBasedSink

      public FileBasedSink(ValueProvider<String> baseOutputFilename,
                           String extension,
                           String fileNamingTemplate)

      Construct a FileBasedSink with the given base output filename, extension, and file naming template.

      See ShardNameTemplate for a description of file naming templates.

  • Method Detail

    • getBaseOutputFilename

      public String getBaseOutputFilename()

      Returns the base output filename for this file based sink.

    • getBaseOutputFilenameProvider

      public ValueProvider<String> getBaseOutputFilenameProvider()

      Returns the base output filename for this file based sink.

    • validate

      public void validate(PipelineOptions options)

      Perform pipeline-construction-time validation. The default implementation is a no-op. Subclasses should override to ensure the sink is valid and can be written to. It is recommended to use Preconditions in the implementation of this method.

      Specified by:

      validate in class Sink<T>

    • createWriteOperation

      public abstract FileBasedSink.FileBasedWriteOperation<T> createWriteOperation(PipelineOptions options)

      Return a subclass of FileBasedSink.FileBasedWriteOperation that will manage the write to the sink.

      Specified by:

      createWriteOperation in class Sink<T>

    • populateDisplayData

      public void populateDisplayData(DisplayData.Builder builder)

      Description copied from class: Sink
      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 Sink<T>

      Parameters:

      builder - The builder to populate with display data.

      See Also:

      HasDisplayData