javax.slee.management
Class AlarmThresholdFilter

java.lang.Object
  javax.slee.management.AlarmThresholdFilter

All Implemented Interfaces:

java.io.Serializable, javax.management.NotificationFilter

public class AlarmThresholdFilter
extends java.lang.Object
implements javax.management.NotificationFilter

A notification filter that supresses equivalent AlarmNotifications until a specified number have occurred within a specified time period. Once the threshold has been reached, the next equivalent alarm notification is allowed through the filter, and the cycle restarts. The cycle also restarts if the time period from the first notification expires without a notification being sent. This filter can be used to suppress alarms that occur and then clear up spontaneously.

Formally: Given a series of duplicate alarm notifications, if threshold + 1 notification are observed within period milliseconds of the first notification, notification number threshold + 1 is delivered to notification listeners and counting restarts from notification number threshold + 2.

Alarm notification equivalence is tested using the AlarmNotification.equals(java.lang.Object) method.

Notifications that are not instances of AlarmNotification are suppressed by this filter.

Note: This filter implementation does not use threads to clear stale timeouts. Instead, stale timeouts are cleared on each invocation of isNotificationEnabled. Methods in this class are also thread-safe.

See Also:

Serialized Form

Constructor Summary

AlarmThresholdFilter(int threshold, long period)
Create an AlarmThresholdFilter.

Method Summary

boolean

isNotificationEnabled(javax.management.Notification notification) Determine whether the specified notification should be delivered to notification listeners using this notification filter.

Methods inherited from class java.lang.Object

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

Constructor Detail

AlarmThresholdFilter

public AlarmThresholdFilter(int threshold,
                            long period)

Create an AlarmThresholdFilter.

Parameters:

threshold - the number of duplicate notifications that must occur within the specified time period before the following duplicate notification is delivered to notification listeners.

period - the period (measured in ms) during which duplicate alarm notifications within the threshold number will be discarded.

Method Detail

isNotificationEnabled

public boolean isNotificationEnabled(javax.management.Notification notification)

Determine whether the specified notification should be delivered to notification listeners using this notification filter.

Specified by:

isNotificationEnabled in interface javax.management.NotificationFilter

Parameters:

notification - the notification to be sent.

Returns:

true if the notification should be delivered to notification listeners, false otherwise. This method always returns false if notification is not an instance of AlarmNotification.