DefaultCoder (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.coders

Annotation Type DefaultCoder

• ---

  
  

  @Documented
   @Retention(value=RUNTIME)
   @Target(value=TYPE)
  public @interface DefaultCoder

  The DefaultCoder annotation specifies a default Coder class to handle encoding and decoding instances of the annotated class.

  The specified Coder must satisfy the requirements of CoderProviders.fromStaticMethods(java.lang.Class<T>). Two classes provided by the SDK that are intended for use with this annotation include SerializableCoder and AvroCoder.

  To configure the use of Java serialization as the default for a class, annotate the class to use SerializableCoder as follows:

   @DefaultCoder(SerializableCoder.class)
   public class MyCustomDataType implements Serializable {
     // ...
   }

  Similarly, to configure the use of AvroCoder as the default:

   @DefaultCoder(AvroCoder.class)
   public class MyCustomDataType {
     public MyCustomDataType() {}  // Avro requires an empty constructor.
     // ...
   }

  Coders specified explicitly via PCollection.setCoder(com.google.cloud.dataflow.sdk.coders.Coder<T>) take precedence, followed by Coders registered at runtime via CoderRegistry.registerCoder(java.lang.Class<?>, java.lang.Class<?>). See CoderRegistry for a more detailed discussion of the precedence rules.

• • Required Element Summary

    Required Elements 

    Modifier and Type	Required Element and Description
    Class<? extends Coder>	value

• • Element Detail

    • value

      public abstract Class<? extends Coder> value