org.apache.flink.api.java.functions

Class GroupReduceIterator<IN,OUT>

java.lang.Object

org.apache.flink.api.common.functions.AbstractRichFunction

org.apache.flink.api.common.functions.RichGroupReduceFunction<IN,OUT>

org.apache.flink.api.java.functions.GroupReduceIterator<IN,OUT>

Type Parameters:

IN -

OUT -

All Implemented Interfaces:

Serializable, Function, GroupReduceFunction<IN,OUT>, RichFunction

@PublicEvolving
public abstract class GroupReduceIterator<IN,OUT>
extends RichGroupReduceFunction<IN,OUT>

Base class that simplifies reducing all values provided as Iterable.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
GroupReduceIterator()

Method Summary

Modifier and Type	Method and Description
void	reduce(Iterable<IN> values, Collector<OUT> out) The reduce method.
abstract Iterator<OUT>	reduceGroup(Iterable<IN> values)

Methods inherited from class org.apache.flink.api.common.functions.AbstractRichFunction

close, getIterationRuntimeContext, getRuntimeContext, open, setRuntimeContext

Methods inherited from class java.lang.Object

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

Constructor Detail

GroupReduceIterator

public GroupReduceIterator()

Method Detail

reduceGroup

public abstract Iterator<OUT> reduceGroup(Iterable<IN> values)
                                   throws Exception

Throws:

Exception

reduce

public final void reduce(Iterable<IN> values,
                         Collector<OUT> out)
                  throws Exception

Description copied from interface: GroupReduceFunction

The reduce method. The function receives one call per group of elements.

Specified by:

reduce in interface GroupReduceFunction<IN,OUT>

Specified by:

reduce in class RichGroupReduceFunction<IN,OUT>

Parameters:

values - All records that belong to the given input key.

out - The collector to hand results to.

Throws:

Exception - This method may throw exceptions. Throwing an exception will cause the operation to fail and may trigger recovery.