Package com.sun.enterprise.admin.monitor.stats

Class MutableAverageRangeStatisticImpl

java.lang.Object

com.sun.enterprise.admin.monitor.stats.MutableAverageRangeStatisticImpl

All Implemented Interfaces:

AverageRangeStatistic, MutableCountStatistic, MutableStatistic, Serializable, RangeStatistic, Statistic

public class MutableAverageRangeStatisticImpl
extends Object
implements AverageRangeStatistic, MutableCountStatistic

An implementation of AverageRangeStatistic that provides ways to change the state externally through mutators. Convenience class that is useful for components that gather the statistical data. By merely changing the count (which is a mandatory measurement), rest of the statistical information could be deduced.

Since:

S1AS8.1

Version:

1.0

Author:

Larry White, Kedar Mhaswade

See Also:

for an immutable implementation, Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static long	DEFAULT_MAX_BOUND	DEFAULT_UPPER_BOUND is maximum value Long can attain

Constructor Summary

Constructors

Constructor	Description
MutableAverageRangeStatisticImpl(BoundedRangeStatistic initial)	Constructs an instance of MutableAverageRangeStatisticImpl that encapsulates the given Statistic.

Method Summary

Modifier and Type	Method	Description
long	getAverage()
long	getCurrent()	The current value of this attribute.
String	getDescription()	A human-readable description of the Statistic.
long	getHighWaterMark()	The highest value this attribute has held since the beginning of the measurement.
long	getLastSampleTime()	The time of the last measurement represented as a long, whose value is the number of milliseconds since January 1, 1970, 00:00:00.
long	getLowWaterMark()	The lowest value this attribute has held since the beginning of the measurement.
String	getName()	The name of this Statistic.
long	getStartTime()	The time of the first measurement represented as a long, whose value is the number of milliseconds since January 1, 1970, 00:00:00.
String	getUnit()	The unit of measurement for this Statistic.
Statistic	modifiableView()	Returns an instance of Statistic whose state can be changed by the caller.
void	reset()	Resets the encapsulated Statistic interface to its initial value.
void	setCount(long current)	Provides the mutator to the only statistic in the implementing class that changes - Count.
Statistic	unmodifiableView()	Returns a read-only view of this Statistic.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_MAX_BOUND

public static final long DEFAULT_MAX_BOUND

DEFAULT_UPPER_BOUND is maximum value Long can attain

See Also:

Constant Field Values

Constructor Detail

MutableAverageRangeStatisticImpl

public MutableAverageRangeStatisticImpl(BoundedRangeStatistic initial)

Constructs an instance of MutableAverageRangeStatisticImpl that encapsulates the given Statistic. The only parameter denotes the initial state of this statistic. It is guaranteed that the initial state is preserved internally, so that one can reset to the initial state.

Parameters:

initial - an instance of BoundedRangeStatistic that represents initial state

Method Detail

modifiableView

public Statistic modifiableView()

Description copied from interface: MutableStatistic

Returns an instance of Statistic whose state can be changed by the caller. It is important to know that caller should not cache the return value from this method. In general, there is a problem in this contract in that, a client would not know from a Stats.getCreateCount() method whether the return value is something that is being modified or is invariant. Hence the caller should not cache the returned value in a collection and then collectively process it. The main idea behind providing this method is to control the number of instances created (per Mahesh's Suggestion).

Specified by:

modifiableView in interface MutableStatistic

Returns:

an instance of Statistic interface that should not be cached.

unmodifiableView

public Statistic unmodifiableView()

Description copied from interface: MutableStatistic

Returns a read-only view of this Statistic. An implementing class has to return the instances of Statistic interfaces defined in javax.management.j2ee.statistic and com.sun.enterprise.admin.monitor.stats packages.

Specified by:

unmodifiableView in interface MutableStatistic

Returns:

an instance of a specific Statistic interface

reset

public void reset()

Description copied from interface: MutableStatistic

Resets the encapsulated Statistic interface to its initial value. The idea being, if (after creation of the instance) the state changes, the initial state can be easily regained by calling this method. Note that the time of last sampling changes to the instant when this method is invoked.

Specified by:

reset in interface MutableStatistic

setCount

public void setCount(long current)

Description copied from interface: MutableCountStatistic

Provides the mutator to the only statistic in the implementing class that changes - Count. It is expected that the count is monotonically increasing on a temporal scale.

Specified by:

setCount in interface MutableCountStatistic

Parameters:

current - long that specifies the value when measured (sampled).

getAverage

public long getAverage()

Specified by:

getAverage in interface AverageRangeStatistic

getCurrent

public long getCurrent()

Description copied from interface: RangeStatistic

The current value of this attribute.

Specified by:

getCurrent in interface RangeStatistic

getDescription

public String getDescription()

Description copied from interface: Statistic

A human-readable description of the Statistic.

Specified by:

getDescription in interface Statistic

getHighWaterMark

public long getHighWaterMark()

Description copied from interface: RangeStatistic

The highest value this attribute has held since the beginning of the measurement.

Specified by:

getHighWaterMark in interface RangeStatistic

getLastSampleTime

public long getLastSampleTime()

Description copied from interface: Statistic

The time of the last measurement represented as a long, whose value is the number of milliseconds since January 1, 1970, 00:00:00.

Specified by:

getLastSampleTime in interface Statistic

getLowWaterMark

public long getLowWaterMark()

Description copied from interface: RangeStatistic

The lowest value this attribute has held since the beginning of the measurement.

Specified by:

getLowWaterMark in interface RangeStatistic

getName

public String getName()

Description copied from interface: Statistic

The name of this Statistic.

Specified by:

getName in interface Statistic

getStartTime

public long getStartTime()

Description copied from interface: Statistic

The time of the first measurement represented as a long, whose value is the number of milliseconds since January 1, 1970, 00:00:00.

Specified by:

getStartTime in interface Statistic

getUnit

public String getUnit()

Description copied from interface: Statistic

The unit of measurement for this Statistic. Valid values for TimeStatistic measurements are "HOUR", "MINUTE", "SECOND", "MILLISECOND", "MICROSECOND" and "NANOSECOND".

Specified by:

getUnit in interface Statistic