com.hazelcast.aggregation.impl

Class AbstractAggregator<I,E,R>

java.lang.Object

com.hazelcast.aggregation.Aggregator<I,R>

com.hazelcast.aggregation.impl.AbstractAggregator<I,E,R>

Type Parameters:

I - input type

E - extracted value type

R - result type

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

BigDecimalAverageAggregator, BigDecimalSumAggregator, BigIntegerAverageAggregator, BigIntegerSumAggregator, CountAggregator, DistinctValuesAggregator, DoubleAverageAggregator, DoubleSumAggregator, FixedSumAggregator, FloatingPointSumAggregator, IntegerAverageAggregator, IntegerSumAggregator, LongAverageAggregator, LongSumAggregator, MaxAggregator, MaxByAggregator, MinAggregator, MinByAggregator, NumberAverageAggregator

public abstract class AbstractAggregator<I,E,R>
extends Aggregator<I,R>

Abstract class providing convenience for concrete implementations of an Aggregator It provides built-in extraction capabilities that may be used in the accumulation phase.

Extraction rules:

• If the attributePath is not null and the input object is an instance of Extractable the value will be extracted from the attributePath in the input object and accumulated instead of the whole input object.
• If the attributePath is null and the input object is an instance of Map.Entry the Map.Entry.getValue() will be accumulated instead of the whole input object.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected String	attributePath

Constructor Summary

Constructors

Constructor and Description
AbstractAggregator()
AbstractAggregator(String attributePath)

Method Summary

Modifier and Type	Method and Description
void	accumulate(I entry) Accumulates the given entries.
protected abstract void	accumulateExtracted(I entry, E value) Accumulates a single extracted value.

Methods inherited from class com.hazelcast.aggregation.Aggregator

aggregate, combine, onAccumulationFinished, onCombinationFinished

Methods inherited from class java.lang.Object

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

Field Detail

attributePath

protected String attributePath

Constructor Detail

AbstractAggregator

public AbstractAggregator()

AbstractAggregator

public AbstractAggregator(String attributePath)

Method Detail

accumulate

public final void accumulate(I entry)

Description copied from class: Aggregator

Accumulates the given entries.

Specified by:

accumulate in class Aggregator<I,R>

Parameters:

entry - input to accumulate.

accumulateExtracted

protected abstract void accumulateExtracted(I entry,
                                            E value)

Accumulates a single extracted value. This method may be called multiple times per accumulated entry if the attributePath contains [any] operator.

Parameters:

entry - The entry containing the value.

value - If attributePath is not null the methods accumulates the value extracted from the attributePath. If attributePath is null and the input object is a Map.Entry the method accumulates Map.Entry.getValue().