com.sun.enterprise.admin.monitor.stats

Interface MutableStatistic

All Superinterfaces:

Serializable

All Known Subinterfaces:

MutableCountStatistic, MutableTimeStatistic

All Known Implementing Classes:

MutableAverageRangeStatisticImpl, MutableBoundedRangeStatisticImpl, MutableCountStatisticImpl, MutableTimeStatisticImpl

public interface MutableStatistic
extends Serializable

An interface that gives a flexibility to set various values for a particular Statistic. This provision is basically to have the same data structure to collect and return the (read-only copy of) statistical data. This extends the java.io.Serializable, so that its subclasses can be serialized to facilitate working with other management clients. Refer to the package description to understand the intent of this interface.

Methods of this class should be called judiciously by the component that is gathering the statistics.

Since:

S1AS8.0

Version:

1.0

Author:

Kedar Mhaswade

Method Summary

Methods

Modifier and Type	Method and Description
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.
Statistic	unmodifiableView() Returns a read-only view of this Statistic.

Method Detail

unmodifiableView

Statistic unmodifiableView()

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

Returns:

an instance of a specific Statistic interface

modifiableView

Statistic modifiableView()

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).

Returns:

an instance of Statistic interface that should not be cached.

reset

void reset()

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.