com.google.cloud.dataflow.sdk.coders

Class ListCoder<T>

java.lang.Object

com.google.cloud.dataflow.sdk.coders.StandardCoder<IT>

com.google.cloud.dataflow.sdk.coders.IterableLikeCoder<T,java.util.List<T>>

com.google.cloud.dataflow.sdk.coders.ListCoder<T>

Type Parameters:

T - the type of the elements of the Lists being transcoded

All Implemented Interfaces:

Coder<java.util.List<T>>, java.io.Serializable

public class ListCoder<T>
extends IterableLikeCoder<T,java.util.List<T>>

A ListCoder encodes Lists.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.cloud.dataflow.sdk.coders.Coder

Coder.Context, Coder.NonDeterministicException

Method Summary

Methods

Modifier and Type	Method and Description
protected java.util.List<T>	decodeToIterable(java.util.List<T> decodedElements) Builds an instance of the coder's associated Iterable from a list of decoded elements.
static <T> java.util.List<java.lang.Object>	getInstanceComponents(java.util.List<T> exampleValue) Returns the first element in this list if it is non-empty, otherwise returns null.
boolean	isDeterministic() Deprecated.
static <T> ListCoder<T>	of(Coder<T> elemCoder)
static ListCoder<?>	of(java.util.List<Coder<?>> components)
void	verifyDeterministic() Throw Coder.NonDeterministicException if the coding is not deterministic.

Methods inherited from class com.google.cloud.dataflow.sdk.coders.IterableLikeCoder

decode, encode, getCoderArguments, getElemCoder, getInstanceComponentsHelper, isRegisterByteSizeObserverCheap, registerByteSizeObserver

Methods inherited from class com.google.cloud.dataflow.sdk.coders.StandardCoder

asCloudObject, equals, getComponents, getEncodedElementByteSize, hashCode, toString, verifyDeterministic, verifyDeterministic

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

of

public static <T> ListCoder<T> of(Coder<T> elemCoder)

decodeToIterable

protected final java.util.List<T> decodeToIterable(java.util.List<T> decodedElements)

Description copied from class: IterableLikeCoder

Builds an instance of the coder's associated Iterable from a list of decoded elements. If IT is a supertype of List<T>, the derived class implementation is permitted to return decodedElements directly.

Specified by:

decodeToIterable in class IterableLikeCoder<T,java.util.List<T>>

of

public static ListCoder<?> of(java.util.List<Coder<?>> components)

getInstanceComponents

public static <T> java.util.List<java.lang.Object> getInstanceComponents(java.util.List<T> exampleValue)

Returns the first element in this list if it is non-empty, otherwise returns null.

isDeterministic

@Deprecated
public boolean isDeterministic()

Deprecated.

List sizes are always known, so ListIterable may be deterministic while the general IterableLikeCoder is not.

Specified by:

isDeterministic in interface Coder<java.util.List<T>>

Overrides:

isDeterministic in class IterableLikeCoder<T,java.util.List<T>>

verifyDeterministic

public void verifyDeterministic()
                         throws Coder.NonDeterministicException

Description copied from interface: Coder

Throw Coder.NonDeterministicException if the coding is not deterministic.

In order for a Coder to be considered deterministic, the following must be true:

• two values which compare as equal (via Object.equals() or Comparable.compareTo(), if supported), have the same encoding.
• the Coder always produces a canonical encoding, which is the same for an instance of an object even if produced on different computers at different times.

Specified by:

verifyDeterministic in interface Coder<java.util.List<T>>

Overrides:

verifyDeterministic in class IterableLikeCoder<T,java.util.List<T>>

Throws:

Coder.NonDeterministicException - if this coder is not deterministic.