com.sun.corba.se.spi.monitoring

Class StatisticsAccumulator

java.lang.Object

com.sun.corba.se.spi.monitoring.StatisticsAccumulator

public class StatisticsAccumulator
extends Object

Author:

Hemanth Puttaswamy

StatisticsAccumulator accumulates the samples provided by the user and computes the value of minimum, maximum, sum and sample square sum. When the StatisticMonitoredAttribute calls getValue(), it will compute all the statistics for the collected samples (Which are Minimum, Maximum, Average, StandardDeviation) and provides a nice printable record as a String. Users can easily extend this class and provide the implementation of toString() method to format the stats as desired. By default all the stats are printed in a single line.

Field Summary

Fields

Modifier and Type	Field and Description
protected double	max
protected double	min
protected String	unit

Constructor Summary

Constructors

Constructor and Description
StatisticsAccumulator(String unit) Construct the Statistics Accumulator by providing the unit as a String.

Method Summary

Modifier and Type	Method and Description
protected double	computeAverage() If users choose to custom format the stats.
protected double	computeStandardDeviation() We use a derived Standard Deviation formula to compute SD.
String	getValue() Computes the Standard Statistic Results based on the samples collected so far and provides the complete value as a formatted String
void	sample(double value) User will use this method to just register a sample with the StatisticsAccumulator.
String	toString() Users can extend StatisticsAccumulator to provide the complete Stats in the format they prefer, if the default format doesn't suffice.
void	unitTestValidate(String expectedUnit, double expectedMin, double expectedMax, long expectedSampleCount, double expectedAverage, double expectedStandardDeviation) This is an internal API to test StatisticsAccumulator...

Methods inherited from class java.lang.Object

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

Field Detail

max

protected double max

min

protected double min

unit

protected String unit

Constructor Detail

StatisticsAccumulator

public StatisticsAccumulator(String unit)

Construct the Statistics Accumulator by providing the unit as a String. The examples of units are "Hours", "Minutes", "Seconds", "MilliSeconds", "Micro Seconds" etc.,

Parameters:

unit - a String representing the units for the samples collected

Method Detail

sample

public void sample(double value)

User will use this method to just register a sample with the StatisticsAccumulator. This is the only method that User will use to expose the statistics, internally the StatisticMonitoredAttribute will collect the information when requested from the ASAdmin.

Parameters:

value - a double value to make it more precise

getValue

public String getValue()

Computes the Standard Statistic Results based on the samples collected so far and provides the complete value as a formatted String

toString

public String toString()

Users can extend StatisticsAccumulator to provide the complete Stats in the format they prefer, if the default format doesn't suffice.

Overrides:

toString in class Object

computeAverage

protected double computeAverage()

If users choose to custom format the stats.

computeStandardDeviation

protected double computeStandardDeviation()

We use a derived Standard Deviation formula to compute SD. This way there is no need to hold on to all the samples provided. The method is protected to let users extend and format the results.

unitTestValidate

public void unitTestValidate(String expectedUnit,
                             double expectedMin,
                             double expectedMax,
                             long expectedSampleCount,
                             double expectedAverage,
                             double expectedStandardDeviation)

This is an internal API to test StatisticsAccumulator...