org.eiichiro.acidhouse

Class Aggregation<T>

java.lang.Object

org.eiichiro.acidhouse.Aggregation<T>

public abstract class Aggregation<T>
extends Object

Aggregation is the base class of aggregation implementation. You can aggregate one property of the GetList command result, by specifying this classes' concrete instance to Session.get(Aggregation) method. Class Aggregations has some factory methods to provide useful Aggregation instances.

Author:

Eiichiro Uchiumi

See Also:

Aggregations

Constructor Summary

Constructors

Constructor and Description
Aggregation(Property<?,T> property) Constructs a new Aggregation instance for the specified property.

Method Summary

Methods

Modifier and Type	Method and Description
abstract T	aggregate(List<T> list) Aggregates the specified list and returns the aggregation result.
Property<?,T>	property() Returns the property that this aggregation instance aggregates.

Methods inherited from class java.lang.Object

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

Constructor Detail

Aggregation

public Aggregation(Property<?,T> property)

Constructs a new Aggregation instance for the specified property.

Parameters:

property - The property to aggregate.

Method Detail

aggregate

public abstract T aggregate(List<T> list)

Aggregates the specified list and returns the aggregation result. This method is called back by the GetScalar implementation. The specified list's entry is the value of the property which this aggregation instance has.

Parameters:

list - The value list of the property which this aggregation instance attempt to aggregate.

Returns:

The aggregation result as a scalar value.

property

public Property<?,T> property()

Returns the property that this aggregation instance aggregates.

Returns:

The property that this aggregation instance aggregates.