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

Class MutableCountStatisticImpl

java.lang.Object
com.sun.enterprise.admin.monitor.stats.MutableCountStatisticImpl
All Implemented Interfaces:
MutableCountStatistic, MutableStatistic, Serializable, CountStatistic, Statistic
public class MutableCountStatisticImpl extends Object implements CountStatistic, MutableCountStatistic
An implementation of MutableCountStatistic that provides ways to change the state externally through mutators. Convenience class that is useful for components that gather the statistical data.
Since:
S1AS8.0
Version:
1.0
Author:
Kedar Mhaswade
See Also:

  • Constructor Details

    • MutableCountStatisticImpl

      public MutableCountStatisticImpl(CountStatistic initial)
      Constructs an instance of MutableCountStatistic 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 CountStatistic that represents initial state

  • Method Details

    • reset

      public void reset()
      Resets to the initial state. It is guaranteed that following changes occur to the statistic if this method is called:
      • The current value is reset to its initial value.
      • The lastSampleTime is reset to current time in milliseconds.
      • The startTime is reset to lastSampleTime.
      The remaining meta data in the statistic is unchanged.
      Specified by:
      reset in interface MutableStatistic

    • setCount

      public void setCount(long count)
      Changes the value of the encapsulated CountStatistic to the given value. Since this is the only mutator exposed here, here are the other side effects of calling this method:
      • lastSampleTime is set to current time in milliseconds.
      In a real-time system with actual probes for measurement, the lastSampleTime could be different from the instant when this method is called, but that is deemed insignificant.
      Specified by:
      setCount in interface MutableCountStatistic
      Parameters:
      count - long that represents the current value of the Statistic.

    • unmodifiableView

      public Statistic unmodifiableView()
      This method is the essence of this class. It provides the read-only view of encapsulated Statistic. If the clients have to know the Statistic, this is what should be called by actual data collecting component to return the value to them. The principle advantage is from the data collecting component's standpoint, in that it does not have to create instances of CountStatistic when its current value is queried/measured.
      Specified by:
      unmodifiableView in interface MutableStatistic
      Returns:
      instance of CountStatistic
      See Also:

    • 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

    • 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

    • getName

      public String getName()
      Description copied from interface: Statistic
      The name of this Statistic.
      Specified by:
      getName in interface Statistic

    • getDescription

      public String getDescription()
      Description copied from interface: Statistic
      A human-readable description of the Statistic.
      Specified by:
      getDescription 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

    • 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.

    • getCount

      public long getCount()
      Description copied from interface: CountStatistic
      The count since the last reset.
      Specified by:
      getCount in interface CountStatistic

    • setDescription

      public void setDescription(String s)