Count (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.transforms

Class Count

• java.lang.Object
• • com.google.cloud.dataflow.sdk.transforms.Count

• ---

  
  

  public class Count
  extends Object

  PTransorms to count the elements in a PCollection.

  perElement() can be used to count the number of occurrences of each distinct element in the PCollection, perKey() can be used to count the number of values per key, and globally() can be used to count the total number of elements in a PCollection.

• • Nested Class Summary

    Nested Classes 

    Modifier and Type	Class and Description
    static class	Count.PerElement<T> Count.PerElement<T> takes a PCollection<T> and returns a PCollection<KV<T, Long>> representing a map from each distinct element of the input PCollection to the number of times that element occurs in the input.

  • Method Summary

    All Methods Static Methods Concrete Methods 

    Modifier and Type	Method and Description
    static <T> Combine.Globally<T,Long>	globally() Returns a Combine.Globally PTransform that counts the number of elements in its input PCollection.
    static <T> Count.PerElement<T>	perElement() Returns a Count.PerElement PTransform that counts the number of occurrences of each element in its input PCollection.
    static <K,V> Combine.PerKey<K,V,Long>	perKey() Returns a Combine.PerKey PTransform that counts the number of elements associated with each key of its input PCollection.

    • Methods inherited from class java.lang.Object

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

• • Method Detail

    • globally

      public static <T> Combine.Globally<T,Long> globally()

      Returns a Combine.Globally PTransform that counts the number of elements in its input PCollection.

    • perKey

      public static <K,V> Combine.PerKey<K,V,Long> perKey()

      Returns a Combine.PerKey PTransform that counts the number of elements associated with each key of its input PCollection.

    • perElement

      public static <T> Count.PerElement<T> perElement()

      Returns a Count.PerElement PTransform that counts the number of occurrences of each element in its input PCollection.

      See Count.PerElement for more details.