org.apache.beam.sdk.values

Class PCollectionViews.SingletonViewFn2<T>

java.lang.Object

org.apache.beam.sdk.transforms.ViewFn<Materializations.IterableView<T>,T>

org.apache.beam.sdk.values.PCollectionViews.SingletonViewFn2<T>

All Implemented Interfaces:

java.io.Serializable, PCollectionViews.HasDefaultValue<T>

Enclosing class:

PCollectionViews

@Experimental(value=CORE_RUNNERS_ONLY)
 @Internal
public static class PCollectionViews.SingletonViewFn2<T>
extends ViewFn<Materializations.IterableView<T>,T>
implements PCollectionViews.HasDefaultValue<T>

Implementation which is able to adapt an iterable materialization to a T.

For internal use only.

Instantiate via PCollectionViews.singletonView(org.apache.beam.sdk.values.PCollection<T>, org.apache.beam.sdk.values.PCollectionViews.TypeDescriptorSupplier<T>, org.apache.beam.sdk.values.WindowingStrategy<?, W>, boolean, T, org.apache.beam.sdk.coders.Coder<T>).

PCollectionViews.SingletonViewFn is meant to be removed in the future and replaced with this class.

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
T	apply(Materializations.IterableView<T> primitiveViewT) A function to adapt a primitive view type to a desired view type.
T	getDefaultValue() Returns the default value that was specified.
Materialization<Materializations.IterableView<T>>	getMaterialization() Gets the materialization of this ViewFn.
TypeDescriptor<T>	getTypeDescriptor() Return the TypeDescriptor describing the output of this fn.
boolean	hasDefault() Returns if a default value was specified.

Methods inherited from class java.lang.Object

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

Method Detail

hasDefault

@Internal
public boolean hasDefault()

Returns if a default value was specified.

getDefaultValue

public T getDefaultValue()

Returns the default value that was specified.

For internal use only.

Specified by:

getDefaultValue in interface PCollectionViews.HasDefaultValue<T>

Throws:

java.util.NoSuchElementException - if no default was specified.

getMaterialization

public Materialization<Materializations.IterableView<T>> getMaterialization()

Description copied from class: ViewFn

Gets the materialization of this ViewFn.

Specified by:

getMaterialization in class ViewFn<Materializations.IterableView<T>,T>

apply

public T apply(Materializations.IterableView<T> primitiveViewT)

Description copied from class: ViewFn

A function to adapt a primitive view type to a desired view type.

Specified by:

apply in class ViewFn<Materializations.IterableView<T>,T>

getTypeDescriptor

public TypeDescriptor<T> getTypeDescriptor()

Description copied from class: ViewFn

Return the TypeDescriptor describing the output of this fn.

Specified by:

getTypeDescriptor in class ViewFn<Materializations.IterableView<T>,T>