org.apache.flink.api.common.accumulators

Class ListAccumulator<T>

java.lang.Object

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

Type Parameters:

T - The type of the accumulated objects

All Implemented Interfaces:

Serializable, Cloneable, Accumulator<T,ArrayList<T>>

@Public
public class ListAccumulator<T>
extends Object
implements Accumulator<T,ArrayList<T>>

This accumulator stores a collection of objects.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ListAccumulator()

Method Summary

Modifier and Type	Method and Description
void	add(T value)
Accumulator<T,ArrayList<T>>	clone() Duplicates the accumulator.
ArrayList<T>	getLocalValue()
void	merge(Accumulator<T,ArrayList<T>> 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

ListAccumulator

public ListAccumulator()

Method Detail

add

public void add(T value)

Specified by:

add in interface Accumulator<T,ArrayList<T>>

Parameters:

value - The value to add to the accumulator object

getLocalValue

public ArrayList<T> getLocalValue()

Specified by:

getLocalValue in interface Accumulator<T,ArrayList<T>>

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<T>>

merge

public void merge(Accumulator<T,ArrayList<T>> 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<T>>

Parameters:

other - Reference to accumulator to merge in.

clone

public Accumulator<T,ArrayList<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<T>>

Overrides:

clone in class Object

Returns:

The duplicated accumulator.

toString

public String toString()

Overrides:

toString in class Object