org.apache.beam.sdk.values

Class TypedPValue<T>

java.lang.Object

org.apache.beam.sdk.values.POutputValueBase

org.apache.beam.sdk.values.PValueBase

org.apache.beam.sdk.values.TypedPValue<T>

Type Parameters:

T - the type of the values stored in this TypedPValue

All Implemented Interfaces:

PInput, POutput, PValue

Direct Known Subclasses:

PCollection

public abstract class TypedPValue<T>
extends PValueBase
implements PValue

A TypedPValue<T> is the abstract base class of things that store some number of values of type T.

Because we know the type T, this is the layer of the inheritance hierarchy where we store a coder for objects of type T.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	TypedPValue(Pipeline p)

Method Summary

Modifier and Type	Method and Description
void	finishSpecifying() After building, finalizes this PValue to make it ready for running.
Coder<T>	getCoder() Returns the Coder used by this TypedPValue to encode and decode the values stored in it.
TypeDescriptor<T>	getTypeDescriptor() Returns a TypeDescriptor<T> with some reflective information about T, if possible.
TypedPValue<T>	setCoder(Coder<T> coder) Sets the Coder used by this TypedPValue to encode and decode the values stored in it.
TypedPValue<T>	setTypeDescriptorInternal(TypeDescriptor<T> typeDescriptor) Sets the TypeDescriptor<T> associated with this class.

Methods inherited from class org.apache.beam.sdk.values.PValueBase

expand, getKindString, getName, isFinishedSpecifyingInternal, recordAsOutput, recordAsOutput, setName, toString

Methods inherited from class org.apache.beam.sdk.values.POutputValueBase

finishSpecifyingOutput, getPipeline, getProducingTransformInternal

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.beam.sdk.values.PValue

getName, getProducingTransformInternal

Methods inherited from interface org.apache.beam.sdk.values.POutput

expand, finishSpecifyingOutput, getPipeline, recordAsOutput

Methods inherited from interface org.apache.beam.sdk.values.PInput

expand, getPipeline

Constructor Detail

TypedPValue

protected TypedPValue(Pipeline p)

Method Detail

getCoder

public Coder<T> getCoder()

Returns the Coder used by this TypedPValue to encode and decode the values stored in it.

Throws:

IllegalStateException - if the Coder hasn't been set, and couldn't be inferred.

setCoder

public TypedPValue<T> setCoder(Coder<T> coder)

Sets the Coder used by this TypedPValue to encode and decode the values stored in it. Returns this.

Throws:

IllegalStateException - if this TypedPValue has already been finalized and is no longer settable, e.g., by having apply() called on it

finishSpecifying

public void finishSpecifying()

After building, finalizes this PValue to make it ready for running. Automatically invoked whenever the PValue is "used" (e.g., when apply() is called on it) and when the Pipeline is run (useful if this is a PValue with no consumers).

Specified by:

finishSpecifying in interface PInput

Overrides:

finishSpecifying in class PValueBase

getTypeDescriptor

public TypeDescriptor<T> getTypeDescriptor()

Returns a TypeDescriptor<T> with some reflective information about T, if possible. May return null if no information is available. Subclasses may override this to enable better Coder inference.

setTypeDescriptorInternal

public TypedPValue<T> setTypeDescriptorInternal(TypeDescriptor<T> typeDescriptor)

Sets the TypeDescriptor<T> associated with this class. Better reflective type information will lead to better Coder inference.