Read.Unbounded (Google Cloud Dataflow SDK 1.9.1 API)

Google Cloud Dataflow SDK for Java, version 1.9.1

Warning: Cloud Dataflow SDK 1.x for Java is unsupported as of October 16, 2018. See Migrating from Cloud Dataflow SDK 1.x for Java for migration guidance.

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 Read.Unbounded<T>

• java.lang.Object
• • com.google.cloud.dataflow.sdk.transforms.PTransform<PInput,PCollection<T>>
  • • com.google.cloud.dataflow.sdk.io.Read.Unbounded<T>

• All Implemented Interfaces:

  HasDisplayData, Serializable

  Enclosing class:

  Read

  ---

  
  

  public static class Read.Unbounded<T>
  extends PTransform<PInput,PCollection<T>>

  PTransform that reads from a UnboundedSource.

  See Also:

  Serialized Form

• • Field Summary

    • Fields inherited from class com.google.cloud.dataflow.sdk.transforms.PTransform

      name

  • Method Summary

    All Methods Instance Methods Concrete Methods 

    Modifier and Type	Method and Description
    PCollection<T>	apply(PInput input) Applies this PTransform on the given InputT, and returns its Output.
    protected Coder<T>	getDefaultOutputCoder() Returns the default Coder to use for the output of this single-output PTransform.
    String	getKindString() Returns the name to use by default for this PTransform (not including the names of any enclosing PTransforms).
    UnboundedSource<T,?>	getSource() Returns the UnboundedSource used to create this Read PTransform.
    Read.Unbounded<T>	named(String name) Returns a new Unbounded PTransform that's like this one but has the given name.
    void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.
    com.google.cloud.dataflow.sdk.io.BoundedReadFromUnboundedSource<T>	withMaxNumRecords(long maxNumRecords) Returns a new BoundedReadFromUnboundedSource that reads a bounded amount of data from the given UnboundedSource.
    com.google.cloud.dataflow.sdk.io.BoundedReadFromUnboundedSource<T>	withMaxReadTime(Duration maxReadTime) Returns a new BoundedReadFromUnboundedSource that reads a bounded amount of data from the given UnboundedSource.

    • Methods inherited from class com.google.cloud.dataflow.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

    • named

      public Read.Unbounded<T> named(String name)

      Returns a new Unbounded PTransform that's like this one but has the given name.

      Does not modify this object.

    • withMaxNumRecords

      public com.google.cloud.dataflow.sdk.io.BoundedReadFromUnboundedSource<T> withMaxNumRecords(long maxNumRecords)

      Returns a new BoundedReadFromUnboundedSource that reads a bounded amount of data from the given UnboundedSource. The bound is specified as a number of records to read.

      This may take a long time to execute if the splits of this source are slow to read records.

    • withMaxReadTime

      public com.google.cloud.dataflow.sdk.io.BoundedReadFromUnboundedSource<T> withMaxReadTime(Duration maxReadTime)

      Returns a new BoundedReadFromUnboundedSource that reads a bounded amount of data from the given UnboundedSource. The bound is specified as an amount of time to read for. Each split of the source will read for this much time.

    • getDefaultOutputCoder

      protected Coder<T> 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<PInput,PCollection<T>>

    • apply

      public final PCollection<T> apply(PInput 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).

      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<InputT, OutputT>, InputT).

      Overrides:

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

    • getSource

      public UnboundedSource<T,?> getSource()

      Returns the UnboundedSource used to create this Read PTransform.

    • getKindString

      public 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<PInput,PCollection<T>>

    • 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<PInput,PCollection<T>>

      Parameters:

      builder - The builder to populate with display data.

      See Also:

      HasDisplayData