Class Monitor

    • Field Detail

      • capacityIncrement

        protected static final int capacityIncrement
        The amount by which the capacity of the monitor arrays are automatically incremented when their size becomes greater than their capacity.
        See Also:
        Constant Field Values
      • elementCount

        protected int elementCount
        The number of valid components in the vector of observed objects.
      • alreadyNotified

        @Deprecated
        protected int alreadyNotified
        Deprecated.
        equivalent to alreadyNotifieds[0].
        Monitor errors that have already been notified.
      • alreadyNotifieds

        protected int[] alreadyNotifieds

        Selected monitor errors that have already been notified.

        Each element in this array corresponds to an observed object in the vector. It contains a bit mask of the flags OBSERVED_OBJECT_ERROR_NOTIFIED etc, indicating whether the corresponding notification has already been sent for the MBean being monitored.

      • server

        protected MBeanServer server
        Reference to the MBean server. This reference is null when the monitor MBean is not registered in an MBean server. This reference is initialized before the monitor MBean is registered in the MBean server.
        See Also:
        preRegister(MBeanServer server, ObjectName name)
      • RESET_FLAGS_ALREADY_NOTIFIED

        protected static final int RESET_FLAGS_ALREADY_NOTIFIED
        This flag is used to reset the alreadyNotifieds monitor attribute.
        See Also:
        Constant Field Values
      • OBSERVED_OBJECT_ERROR_NOTIFIED

        protected static final int OBSERVED_OBJECT_ERROR_NOTIFIED
        Flag denoting that a notification has occurred after changing the observed object. This flag is used to check that the new observed object is registered in the MBean server at the time of the first notification.
        See Also:
        Constant Field Values
      • OBSERVED_ATTRIBUTE_ERROR_NOTIFIED

        protected static final int OBSERVED_ATTRIBUTE_ERROR_NOTIFIED
        Flag denoting that a notification has occurred after changing the observed attribute. This flag is used to check that the new observed attribute belongs to the observed object at the time of the first notification.
        See Also:
        Constant Field Values
      • OBSERVED_ATTRIBUTE_TYPE_ERROR_NOTIFIED

        protected static final int OBSERVED_ATTRIBUTE_TYPE_ERROR_NOTIFIED
        Flag denoting that a notification has occurred after changing the observed object or the observed attribute. This flag is used to check that the observed attribute type is correct (depending on the monitor in use) at the time of the first notification.
        See Also:
        Constant Field Values
      • RUNTIME_ERROR_NOTIFIED

        protected static final int RUNTIME_ERROR_NOTIFIED
        Flag denoting that a notification has occurred after changing the observed object or the observed attribute. This flag is used to notify any exception (except the cases described above) when trying to get the value of the observed attribute at the time of the first notification.
        See Also:
        Constant Field Values
      • dbgTag

        @Deprecated
        protected String dbgTag
        Deprecated.
        No replacement.
        This field is retained for compatibility but should not be referenced.
    • Constructor Detail

      • Monitor

        public Monitor()
    • Method Detail

      • preRegister

        public ObjectName preRegister​(MBeanServer server,
                                      ObjectName name)
                               throws Exception
        Allows the monitor MBean to perform any operations it needs before being registered in the MBean server.

        Initializes the reference to the MBean server.

        Specified by:
        preRegister in interface MBeanRegistration
        Parameters:
        server - The MBean server in which the monitor MBean will be registered.
        name - The object name of the monitor MBean.
        Returns:
        The name of the monitor MBean registered.
        Throws:
        Exception - if something goes wrong
      • postRegister

        public void postRegister​(Boolean registrationDone)
        Allows the monitor MBean to perform any operations needed after having been registered in the MBean server or after the registration has failed.

        Not used in this context.

        Specified by:
        postRegister in interface MBeanRegistration
        Parameters:
        registrationDone - Indicates whether or not the MBean has been successfully registered in the MBean server. The value false means that the registration phase has failed.
      • preDeregister

        public void preDeregister()
                           throws Exception
        Allows the monitor MBean to perform any operations it needs before being unregistered by the MBean server.

        Stops the monitor.

        Specified by:
        preDeregister in interface MBeanRegistration
        Throws:
        Exception - if something goes wrong
      • postDeregister

        public void postDeregister()
        Allows the monitor MBean to perform any operations needed after having been unregistered by the MBean server.

        Not used in this context.

        Specified by:
        postDeregister in interface MBeanRegistration
      • start

        public abstract void start()
        Starts the monitor.
        Specified by:
        start in interface MonitorMBean
      • stop

        public abstract void stop()
        Stops the monitor.
        Specified by:
        stop in interface MonitorMBean
      • removeObservedObject

        public void removeObservedObject​(ObjectName object)
        Removes the specified object from the set of observed MBeans.
        Specified by:
        removeObservedObject in interface MonitorMBean
        Parameters:
        object - The object to remove.
      • containsObservedObject

        public boolean containsObservedObject​(ObjectName object)
        Tests whether the specified object is in the set of observed MBeans.
        Specified by:
        containsObservedObject in interface MonitorMBean
        Parameters:
        object - The object to check.
        Returns:
        true if the specified object is present, false otherwise.
      • getObservedObjects

        public ObjectName[] getObservedObjects()
        Returns an array containing the objects being observed.
        Specified by:
        getObservedObjects in interface MonitorMBean
        Returns:
        The objects being observed.
      • getGranularityPeriod

        public long getGranularityPeriod()
        Gets the granularity period (in milliseconds).
        The default value of the granularity period is 10 seconds.
        Specified by:
        getGranularityPeriod in interface MonitorMBean
        Returns:
        The granularity period value.
        See Also:
        setGranularityPeriod(long)
      • isActive

        public boolean isActive()
        Tests whether the monitor MBean is active. A monitor MBean is marked active when the start method is called. It becomes inactive when the stop method is called.
        Specified by:
        isActive in interface MonitorMBean
        Returns:
        true if the monitor MBean is active, false otherwise.