Package org.apache.flink.api.common.accumulators

Class SerializedListAccumulator<T>

java.lang.Object

org.apache.flink.api.common.accumulators.SerializedListAccumulator<T>

Type Parameters:

T - The type of the accumulated objects

All Implemented Interfaces:

Serializable, Cloneable, Accumulator<T,ArrayList<byte[]>>

@PublicEvolving
public class SerializedListAccumulator<T>
extends Object
implements Accumulator<T,ArrayList<byte[]>>

This accumulator stores a collection of objects in serialized form, so that the stored objects are not affected by modifications to the original objects.

Objects may be deserialized on demand with a specific classloader.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
SerializedListAccumulator()

Method Summary

Modifier and Type	Method	Description
void	add(T value)
void	add(T value, TypeSerializer<T> serializer)
SerializedListAccumulator<T>	clone()	Duplicates the accumulator.
static <T> List<T>	deserializeList(ArrayList<byte[]> data, TypeSerializer<T> serializer)
ArrayList<byte[]>	getLocalValue()
void	merge(Accumulator<T,ArrayList<byte[]>> other)	Used by system internally to merge the collected parts of an accumulator at the end of the job.
void	resetLocal()	Reset the local value.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

SerializedListAccumulator

public SerializedListAccumulator()

Method Detail

add

public void add(T value)

Specified by:

add in interface Accumulator<T,ArrayList<byte[]>>

Parameters:

value - The value to add to the accumulator object

add

public void add(T value,
                TypeSerializer<T> serializer)
         throws IOException

Throws:

IOException

getLocalValue

public ArrayList<byte[]> getLocalValue()

Specified by:

getLocalValue in interface Accumulator<T,ArrayList<byte[]>>

Returns:

local The local value from the current UDF context

resetLocal

public void resetLocal()

Description copied from interface: Accumulator

Reset the local value. This only affects the current UDF context.

Specified by:

resetLocal in interface Accumulator<T,ArrayList<byte[]>>

merge

public void merge(Accumulator<T,ArrayList<byte[]>> other)

Description copied from interface: Accumulator

Used by system internally to merge the collected parts of an accumulator at the end of the job.

Specified by:

merge in interface Accumulator<T,ArrayList<byte[]>>

Parameters:

other - Reference to accumulator to merge in.

clone

public SerializedListAccumulator<T> clone()

Description copied from interface: Accumulator

Duplicates the accumulator. All subclasses need to properly implement cloning and cannot throw a CloneNotSupportedException

Specified by:

clone in interface Accumulator<T,ArrayList<byte[]>>

Overrides:

clone in class Object

Returns:

The duplicated accumulator.

deserializeList

public static <T> List<T> deserializeList(ArrayList<byte[]> data,
                                          TypeSerializer<T> serializer)
                                   throws IOException,
                                          ClassNotFoundException

Throws:

IOException

ClassNotFoundException

toString

public String toString()

Overrides:

toString in class Object