saffron.ext
Class Nth

java.lang.Object
  |
  +--saffron.ext.Nth

All Implemented Interfaces:

AggregationExtender

public class Nth

extends Object

implements AggregationExtender

Nth is an example of a custom aggregation. It returns the the n^th of a set of rows, or returns null (0 for a primitive type) if there are not that many rows. It implements the overloaded T aggregate(T) method for T = {int, double, Object}. There is a start, next, and result method for each.

Since:

11 February, 2002

Version:

$Id: //open/saffron/src/main/saffron/ext/Nth.java#1 $

Author:

jhyde

Nested Class Summary

private static class	Nth.Holder_double
private static class	Nth.Holder_int
private static class	Nth.Holder_Object

Field Summary

private int

n

Fields inherited from interface saffron.AggregationExtender

METHOD_AGGREGATE, METHOD_MERGE, METHOD_NEXT, METHOD_RESULT, METHOD_START

Constructor Summary

Nth(int n)

Method Summary

double	aggregate(double value)
int	aggregate(int value)
Object	aggregate(Object value)
Object	next(double value, Object accumulator)
Object	next(int value, Object accumulator)
Object	next(Object value, Object accumulator)
double	result(double value, Object accumulator)
int	result(int value, Object accumulator)
Object	result(Object value, Object accumulator)
Object	start(double value)
Object	start(int value)
Object	start(Object value)

Methods inherited from class java.lang.Object

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

Field Detail

n

private int n

Constructor Detail

Nth

public Nth(int n)

Method Detail

aggregate

public int aggregate(int value)

start

public Object start(int value)

next

public Object next(int value,
                   Object accumulator)

result

public int result(int value,
                  Object accumulator)

aggregate

public double aggregate(double value)

start

public Object start(double value)

next

public Object next(double value,
                   Object accumulator)

result

public double result(double value,
                     Object accumulator)

aggregate

public Object aggregate(Object value)

start

public Object start(Object value)

next

public Object next(Object value,
                   Object accumulator)

result

public Object result(Object value,
                     Object accumulator)