com.tangosol.util.aggregator
Class AbstractDoubleAggregator

java.lang.Object
  com.tangosol.util.Base
      com.tangosol.util.BitHelper
          com.tangosol.util.ExternalizableHelper
              com.tangosol.util.aggregator.AbstractAggregator
                  com.tangosol.util.aggregator.AbstractDoubleAggregator

All Implemented Interfaces:

ExternalizableLite, PortableObject, InvocableMap.EntryAggregator, InvocableMap.ParallelAwareAggregator, Serializable

Direct Known Subclasses:

DoubleAverage, DoubleMax, DoubleMin, DoubleSum

public abstract class AbstractDoubleAggregator
extends AbstractAggregator

Abstract aggregator that processes numeric values extracted from a set of entries in a Map. All the extracted Number objects will be treated as Java double values and the result of the aggregator is a Double. If the set of entries is empty, a null result is returned.

Since:

Coherence 3.1

Author:

cp/gg/jh 2005.07.19

Field Summary

protected int	m_count The count of processed entries.
protected double	m_dflResult The running result value.

Fields inherited from class com.tangosol.util.aggregator.AbstractAggregator

m_fParallel

Constructor Summary

AbstractDoubleAggregator()
Default constructor (necessary for the ExternalizableLite interface).

AbstractDoubleAggregator(String sMethod)
Construct an AbstractDoubleAggregator object.

AbstractDoubleAggregator(ValueExtractor extractor)
Construct an AbstractDoubleAggregator object.

Method Summary

protected Object	finalizeResult(boolean fFinal) Obtain the result of the aggregation.
protected void	init(boolean fFinal) Initialize the aggregation result.

Methods inherited from class com.tangosol.util.aggregator.AbstractAggregator

aggregate, aggregateResults, equals, getParallelAggregator, getValueExtractor, hashCode, process, readExternal, readExternal, toString, writeExternal, writeExternal

Methods inherited from class com.tangosol.util.BitHelper

countBits, countBits, countBits, indexOfLSB, indexOfLSB, indexOfLSB, indexOfMSB, indexOfMSB, indexOfMSB, toBitString, toBitString, toBitString

Field Detail

m_count

protected transient int m_count

The count of processed entries.

m_dflResult

protected transient double m_dflResult

The running result value.

Constructor Detail

AbstractDoubleAggregator

public AbstractDoubleAggregator()

Default constructor (necessary for the ExternalizableLite interface).

AbstractDoubleAggregator

public AbstractDoubleAggregator(ValueExtractor extractor)

Construct an AbstractDoubleAggregator object.

Parameters:

extractor - the extractor that provides a value in the form of any Java object that is a Number

AbstractDoubleAggregator

public AbstractDoubleAggregator(String sMethod)

Construct an AbstractDoubleAggregator object.

Parameters:

sMethod - the name of the method that returns a value in the form of any Java object that is a Number

Method Detail

init

protected void init(boolean fFinal)

Initialize the aggregation result.

Specified by:

init in class AbstractAggregator

Parameters:

fFinal - true is passed if the aggregation process that is being initialized must produce a final aggregation result; this will only be false if a parallel approach is being used and the initial (partial) aggregation process is being initialized

finalizeResult

protected Object finalizeResult(boolean fFinal)

Obtain the result of the aggregation.

If the fFinal parameter is true, the returned object must be the final result of the aggregation; otherwise, the returned object will be treated as a partial result that should be incorporated into the final result.

Specified by:

finalizeResult in class AbstractAggregator

Parameters:

fFinal - true to indicate that the final result of the aggregation process should be returned; this will only be false if a parallel approach is being used

Returns:

the result of the aggregation process