com.google.cloud.dataflow.sdk.transforms

Class View.AsMap<K,V>

java.lang.Object

com.google.cloud.dataflow.sdk.transforms.PTransform<PCollection<KV<K,V>>,PCollectionView<Map<K,V>>>

com.google.cloud.dataflow.sdk.transforms.View.AsMap<K,V>

All Implemented Interfaces:

Serializable

Enclosing class:

View

public static class View.AsMap<K,V>
extends PTransform<PCollection<KV<K,V>>,PCollectionView<Map<K,V>>>

A PTransform that produces a PCollectionView of a keyed PCollection yielding a map from each key to its unique associated value. When converting a PCollection that has more than one value per key, precede this transform with a Combine.perKey:

 
 PCollectionView<Map<K, OutputT>> input
     .apply(Combine.perKey(myCombineFunction))
     .apply(View.<K, OutputT>asMap());
 

Instantiate via View.asMap().

See Also:

Serialized Form

Field Summary

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

name

Method Summary

Modifier and Type	Method and Description
PCollectionView<Map<K,V>>	apply(PCollection<KV<K,V>> input) Applies this PTransform on the given InputT, and returns its Output.
void	validate(PCollection<KV<K,V>> input) Called before invoking apply (which may be intercepted by the runner) to verify this transform is fully specified and applicable to the specified input.
View.AsMap<K,V>	withSingletonValues() Deprecated. this method simply returns this AsMap unmodified

Methods inherited from class com.google.cloud.dataflow.sdk.transforms.PTransform

getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, toString

Methods inherited from class java.lang.Object

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

Method Detail

withSingletonValues

@Deprecated
public View.AsMap<K,V> withSingletonValues()

Deprecated. this method simply returns this AsMap unmodified

validate

public void validate(PCollection<KV<K,V>> input)

Description copied from class: PTransform

Called before invoking apply (which may be intercepted by the runner) to verify this transform is fully specified and applicable to the specified input.

By default, does nothing.

Overrides:

validate in class PTransform<PCollection<KV<K,V>>,PCollectionView<Map<K,V>>>

apply

public PCollectionView<Map<K,V>> apply(PCollection<KV<K,V>> 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<PCollection<KV<K,V>>,PCollectionView<Map<K,V>>>