net.sf.ehcache.search.aggregator
Interface AggregatorInstance<T>

Type Parameters:

T - the runtime type of aggregation result

All Known Implementing Classes:

Average, Count, Max, Min, Sum

public interface AggregatorInstance<T>

An AggregatorInstance takes input objects and computes an aggregate function from them.

Author:

Greg Luck

Method Summary

void	accept(Object input) Add the given value to the aggregator function
Object	aggregateResult() Retrieve the final result
Attribute<?>	getAttribute() Get the attribute to pass to aggregator

Method Detail

accept

void accept(Object input)
            throws AggregatorException

Add the given value to the aggregator function

Parameters:

input - a single input value

Throws:

AggregatorException - if the function cannot be computed, possibly due to unsupported types

aggregateResult

Object aggregateResult()

Retrieve the final result

Returns:

aggregate result

getAttribute

Attribute<?> getAttribute()

Get the attribute to pass to aggregator

Returns:

attribute to aggregate (null if no attribute is applicable to function)