javax.management.timer
Class Timer

java.lang.Object
  |
  +--javax.management.NotificationBroadcasterSupport
        |
        +--javax.management.timer.Timer

All Implemented Interfaces:

MBeanRegistration, NotificationBroadcaster, NotificationEmitter, TimerMBean

public class Timer

extends NotificationBroadcasterSupport

implements TimerMBean, MBeanRegistration

Provides the implementation of the timer MBean. The timer MBean sends out an alarm at a specified time that wakes up all the listeners registered to receive timer notifications.

This class manages a list of dated timer notifications. A method allows users to add/remove as many notifications as required. When a timer notification is emitted by the timer and becomes obsolete, it is automatically removed from the list of timer notifications.
Additional timer notifications can be added into regularly repeating notifications.

Note:

1. All notifications before the time when the addNotification method is called are ignored, irrespective of the sendPastNotifications flag.
2. When sending timer notifications, the timer updates the notification sequence number irrespective of the notification type.
3. The timer service relies on the system date of the host where the Timer class is loaded. Listeners may receive untimely notifications if their host has a different system date. To avoid such problems, synchronize the system date of all host machines where timing is needed.
4. The default behaviour for periodic notifications is fixed-delay execution, as specified in Timer. In order to use fixed-rate execution, use the overloaded addNotification(String, String, Object, Date, long, long, boolean) method.
5. Notification listeners are potentially all executed in the same thread. Therefore, they should execute rapidly to avoid holding up other listeners or perturbing the regularity of fixed-delay executions. See NotificationBroadcasterSupport.

Author:

Young Yang

Constructor Summary

Timer()

Method Summary

java.lang.Integer	addNotification(java.lang.String type, java.lang.String message, java.lang.Object userData, java.util.Date date) Creates a new timer notification with the specified type, message and userData and inserts it into the list of notifications with a given date and a null period and number of occurences.
java.lang.Integer	addNotification(java.lang.String type, java.lang.String message, java.lang.Object userData, java.util.Date date, long period) Creates a new timer notification with the specified type, message and userData and inserts it into the list of notifications with a given date and period and a null number of occurences.
java.lang.Integer	addNotification(java.lang.String type, java.lang.String message, java.lang.Object userData, java.util.Date date, long period, long nbOccurences) add a notification to the Timer
java.lang.Integer	addNotification(java.lang.String type, java.lang.String message, java.lang.Object userData, java.util.Date date, long period, long nbOccurences, boolean fixedRate) Creates a new timer notification with the specified type, message and userData and inserts it into the list of notifications with a given date, period and number of occurences.
java.util.Vector	getAllNotificationIDs() Gets all timer notification identifiers registered into the list of notifications.
java.util.Date	getDate(java.lang.Integer id) Gets a copy of the date associated to a timer notification.
java.lang.Boolean	getFixedRate(java.lang.Integer id) Gets a copy of the flag indicating whether a peridic notification is executed at fixed-delay or at fixed-rate.
int	getNbNotifications() Gets the number of timer notifications registered into the list of notifications.
java.lang.Long	getNbOccurences(java.lang.Integer id) Gets a copy of the remaining number of occurences associated to a timer notification.
java.util.Vector	getNotificationIDs(java.lang.String type) Gets all the identifiers of timer notifications corresponding to the specified type.
MBeanNotificationInfo[]	getNotificationInfo() Returns a NotificationInfo object contaning the name of the Java class of the notification and the notification types sent.
java.lang.String	getNotificationMessage(java.lang.Integer id) Gets the timer notification detailed message corresponding to the specified identifier.
java.lang.String	getNotificationType(java.lang.Integer id) Gets the timer notification type corresponding to the specified identifier.
java.lang.Object	getNotificationUserData(java.lang.Integer id) Gets the timer notification user data object corresponding to the specified identifier.
java.lang.Long	getPeriod(java.lang.Integer id) Gets a copy of the period (in milliseconds) associated to a timer notification.
boolean	getSendPastNotifications() Gets the flag indicating whether or not the timer sends past notifications.
boolean	isActive() Tests whether the timer MBean is active.
boolean	isEmpty() Tests whether the list of timer notifications is empty.
void	postDeregister() Allows the MBean to perform any operations needed after having been de-registered in the MBean server.
void	postRegister(java.lang.Boolean boolean1) Allows the MBean to perform any operations needed after having been registered in the MBean server or after the registration has failed.
void	preDeregister() Allows the MBean to perform any operations it needs before being de-registered by the MBean server.
ObjectName	preRegister(MBeanServer mbeanserver, ObjectName objectname) Allows the MBean to perform any operations it needs before being registered in the MBean server.
void	removeAllNotifications() Removes all the timer notifications from the list of notifications and resets the counter used to update the timer notification identifiers.
void	removeNotification(java.lang.Integer id) Removes the timer notification corresponding to the specified identifier from the list of notifications.
void	removeNotifications(java.lang.String type) Removes all the timer notifications corresponding to the specified type from the list of notifications.
void	setSendPastNotifications(boolean flag) Sets the flag indicating whether the timer sends past notifications or not.
void	start() Starts the timer.
void	stop() Stops the timer.

Methods inherited from class javax.management.NotificationBroadcasterSupport

addNotificationListener, handleNotification, removeNotificationListener, removeNotificationListener, sendNotification

Methods inherited from class java.lang.Object

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

Constructor Detail

Timer

public Timer()

Method Detail

preRegister

public ObjectName preRegister(MBeanServer mbeanserver,
                              ObjectName objectname)
                       throws java.lang.Exception

Description copied from interface: MBeanRegistration

Allows the MBean to perform any operations it needs before being registered in the MBean server. If the name of the MBean is not specified, the MBean can provide a name for its registration. If any exception is raised, the MBean will not be registered in the MBean server.

Specified by:

preRegister in interface MBeanRegistration

Following copied from interface: javax.management.MBeanRegistration

Parameters:

server - The MBean server in which the MBean will be registered.

name - The object name of the MBean.

Returns:

The name of the MBean registered.

Throws:

java.lang.Exception - This exception should be caught by the MBean server and re-thrown as an MBeanRegistrationException.

postRegister

public void postRegister(java.lang.Boolean boolean1)

Description copied from interface: MBeanRegistration

Allows the MBean to perform any operations needed after having been registered in the MBean server or after the registration has failed.

Specified by:

postRegister in interface MBeanRegistration

Following copied from interface: javax.management.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 java.lang.Exception

Description copied from interface: MBeanRegistration

Allows the MBean to perform any operations it needs before being de-registered by the MBean server.

Specified by:

preDeregister in interface MBeanRegistration

Following copied from interface: javax.management.MBeanRegistration

Throws:

java.lang.Exception - This exception should be caught by the MBean server and re-thrown as an MBeanRegistrationException.

postDeregister

public void postDeregister()

Description copied from interface: MBeanRegistration

Allows the MBean to perform any operations needed after having been de-registered in the MBean server.

Specified by:

postDeregister in interface MBeanRegistration

start

public void start()

Description copied from interface: TimerMBean

Starts the timer.

If there is one or more timer notifications before the time in the list of notifications, the notification is sent according to the sendPastNotifications flag and then, updated according to its period and remaining number of occurences. If the timer notification date remains earlier than the current date, this notification is just removed from the list of notifications.

Specified by:

start in interface TimerMBean

stop

public void stop()

Description copied from interface: TimerMBean

Stops the timer.

Specified by:

stop in interface TimerMBean

addNotification

public java.lang.Integer addNotification(java.lang.String type,
                                         java.lang.String message,
                                         java.lang.Object userData,
                                         java.util.Date date,
                                         long period,
                                         long nbOccurences)
                                  throws java.lang.IllegalArgumentException

add a notification to the Timer

Specified by:

addNotification in interface TimerMBean

Parameters:

type - The notification type string.

message - The notification¡¯s detailed message string.

userData - The notification¡¯s user data object.

date - The date when the notification will occur. The Timer class includes integer constants for expressing durations in milliseconds, which can then be used to doCreate java.util.Date objects.

period - The interval in milliseconds between notification occurrences. Repeating notifications are not enabled if this parameter is zero or null.

nbOccurences - The total number of times that the notification will occur. If the value of this parameter is zero or is not defined (null), and if the period is not zero or null, then the notification will repeat indefinitely.

Returns:

Throws:

java.lang.IllegalArgumentException -

addNotification

public java.lang.Integer addNotification(java.lang.String type,
                                         java.lang.String message,
                                         java.lang.Object userData,
                                         java.util.Date date,
                                         long period)
                                  throws java.lang.IllegalArgumentException

Description copied from interface: TimerMBean

Creates a new timer notification with the specified type, message and userData and inserts it into the list of notifications with a given date and period and a null number of occurences.

The timer notification will repeat continuously using the timer period using a fixed-delay execution scheme, as specified in Timer. In order to use a fixed-rate execution scheme, use TimerMBean.addNotification(String, String, Object, Date, long, long, boolean) instead.

If the timer notification to be inserted has a date that is before the current date, the method behaves as if the specified date were the current date. The first notification is delivered immediately and the subsequent ones are spaced as specified by the period parameter.

Specified by:

addNotification in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

type - The timer notification type.

message - The timer notification detailed message.

userData - The timer notification user data object.

date - The date when the notification occurs.

period - The period of the timer notification (in milliseconds).

Returns:

The identifier of the new created timer notification.

Throws:

java.lang.IllegalArgumentException - The period is negative or the date notification is before the current date.

addNotification

public java.lang.Integer addNotification(java.lang.String type,
                                         java.lang.String message,
                                         java.lang.Object userData,
                                         java.util.Date date)
                                  throws java.lang.IllegalArgumentException

Description copied from interface: TimerMBean

Creates a new timer notification with the specified type, message and userData and inserts it into the list of notifications with a given date and a null period and number of occurences.

The timer notification will be handled once at the specified date.

If the timer notification to be inserted has a date that is before the current date, the method behaves as if the specified date were the current date and the notification is delivered immediately.

Specified by:

addNotification in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

type - The timer notification type.

message - The timer notification detailed message.

userData - The timer notification user data object.

date - The date when the notification occurs.

Returns:

The identifier of the new created timer notification.

Throws:

java.lang.IllegalArgumentException - The date notification is before the current date.

addNotification

public java.lang.Integer addNotification(java.lang.String type,
                                         java.lang.String message,
                                         java.lang.Object userData,
                                         java.util.Date date,
                                         long period,
                                         long nbOccurences,
                                         boolean fixedRate)
                                  throws java.lang.IllegalArgumentException

Description copied from interface: TimerMBean

Creates a new timer notification with the specified type, message and userData and inserts it into the list of notifications with a given date, period and number of occurences.

If the timer notification to be inserted has a date that is before the current date, the method behaves as if the specified date were the current date.
For once-off notifications, the notification is delivered immediately.
For periodic notifications, the first notification is delivered immediately and the subsequent ones are spaced as specified by the period parameter.

Note that once the timer notification has been added into the list of notifications, its associated date, period and number of occurences cannot be updated.

In the case of a periodic notification, the value of parameter fixedRate is used to specify the execution scheme, as specified in Timer.

Specified by:

addNotification in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

type - The timer notification type.

message - The timer notification detailed message.

userData - The timer notification user data object.

date - The date when the notification occurs.

period - The period of the timer notification (in milliseconds).

nbOccurences - The total number the timer notification will be emitted.

fixedRate - If true and if the notification is periodic, the notification is scheduled with a fixed-rate execution scheme. If false and if the notification is periodic, the notification is scheduled with a fixed-delay execution scheme. Ignored if the notification is not periodic.

Returns:

The identifier of the new created timer notification.

Throws:

java.lang.IllegalArgumentException - The period or the number of occurences is negative

See Also:

TimerMBean.addNotification(String, String, Object, Date, long, long)

removeNotification

public void removeNotification(java.lang.Integer id)
                        throws InstanceNotFoundException

Description copied from interface: TimerMBean

Removes the timer notification corresponding to the specified identifier from the list of notifications.

Specified by:

removeNotification in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

id - The timer notification identifier.

Throws:

InstanceNotFoundException - The specified identifier does not correspond to any timer notification in the list of notifications of this timer MBean.

removeNotifications

public void removeNotifications(java.lang.String type)
                         throws InstanceNotFoundException

Description copied from interface: TimerMBean

Removes all the timer notifications corresponding to the specified type from the list of notifications.

Specified by:

removeNotifications in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

type - The timer notification type.

Throws:

InstanceNotFoundException - The specified type does not correspond to any timer notification in the list of notifications of this timer MBean.

removeAllNotifications

public void removeAllNotifications()

Description copied from interface: TimerMBean

Removes all the timer notifications from the list of notifications and resets the counter used to update the timer notification identifiers.

Specified by:

removeAllNotifications in interface TimerMBean

getNbNotifications

public int getNbNotifications()

Description copied from interface: TimerMBean

Gets the number of timer notifications registered into the list of notifications.

Specified by:

getNbNotifications in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Returns:

The number of timer notifications.

getAllNotificationIDs

public java.util.Vector getAllNotificationIDs()

Description copied from interface: TimerMBean

Gets all timer notification identifiers registered into the list of notifications.

Specified by:

getAllNotificationIDs in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Returns:

A vector of Integer objects containing all the timer notification identifiers.
The vector is empty if there is no timer notification registered for this timer MBean.

getNotificationIDs

public java.util.Vector getNotificationIDs(java.lang.String type)

Description copied from interface: TimerMBean

Gets all the identifiers of timer notifications corresponding to the specified type.

Specified by:

getNotificationIDs in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

type - The timer notification type.

Returns:

A vector of Integer objects containing all the identifiers of timer notifications with the specified type.
The vector is empty if there is no timer notifications registered for this timer MBean with the specified type.

getNotificationType

public java.lang.String getNotificationType(java.lang.Integer id)

Description copied from interface: TimerMBean

Gets the timer notification type corresponding to the specified identifier.

Specified by:

getNotificationType in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

id - The timer notification identifier.

Returns:

The timer notification type or null if the identifier is not mapped to any timer notification registered for this timer MBean.

getNotificationMessage

public java.lang.String getNotificationMessage(java.lang.Integer id)

Description copied from interface: TimerMBean

Gets the timer notification detailed message corresponding to the specified identifier.

Specified by:

getNotificationMessage in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

id - The timer notification identifier.

Returns:

The timer notification detailed message or null if the identifier is not mapped to any timer notification registered for this timer MBean.

getNotificationUserData

public java.lang.Object getNotificationUserData(java.lang.Integer id)

Description copied from interface: TimerMBean

Gets the timer notification user data object corresponding to the specified identifier.

Specified by:

getNotificationUserData in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

id - The timer notification identifier.

Returns:

The timer notification user data object or null if the identifier is not mapped to any timer notification registered for this timer MBean.

getDate

public java.util.Date getDate(java.lang.Integer id)

Description copied from interface: TimerMBean

Gets a copy of the date associated to a timer notification.

Specified by:

getDate in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

id - The timer notification identifier.

Returns:

A copy of the date or null if the identifier is not mapped to any timer notification registered for this timer MBean.

getPeriod

public java.lang.Long getPeriod(java.lang.Integer id)

Description copied from interface: TimerMBean

Gets a copy of the period (in milliseconds) associated to a timer notification.

Specified by:

getPeriod in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

id - The timer notification identifier.

Returns:

A copy of the period or null if the identifier is not mapped to any timer notification registered for this timer MBean.

getNbOccurences

public java.lang.Long getNbOccurences(java.lang.Integer id)

Description copied from interface: TimerMBean

Gets a copy of the remaining number of occurences associated to a timer notification.

Specified by:

getNbOccurences in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

id - The timer notification identifier.

Returns:

A copy of the remaining number of occurences or null if the identifier is not mapped to any timer notification registered for this timer MBean.

getFixedRate

public java.lang.Boolean getFixedRate(java.lang.Integer id)

Description copied from interface: TimerMBean

Gets a copy of the flag indicating whether a peridic notification is executed at fixed-delay or at fixed-rate.

Specified by:

getFixedRate in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

id - The timer notification identifier.

Returns:

A copy of the flag indicating whether a peridic notification is executed at fixed-delay or at fixed-rate.

getSendPastNotifications

public boolean getSendPastNotifications()

Description copied from interface: TimerMBean

Gets the flag indicating whether or not the timer sends past notifications.

Specified by:

getSendPastNotifications in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Returns:

The past notifications sending on/off flag value.

See Also:

TimerMBean.setSendPastNotifications(boolean)

setSendPastNotifications

public void setSendPastNotifications(boolean flag)

Description copied from interface: TimerMBean

Sets the flag indicating whether the timer sends past notifications or not.

Specified by:

setSendPastNotifications in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Parameters:

value - The past notifications sending on/off flag value.

See Also:

TimerMBean.getSendPastNotifications()

isActive

public boolean isActive()

Description copied from interface: TimerMBean

Tests whether the timer MBean is active. A timer MBean is marked active when the doStart method is called. It becomes inactive when the doStop method is called.

Specified by:

isActive in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Returns:

true if the timer MBean is active, false otherwise.

isEmpty

public boolean isEmpty()

Description copied from interface: TimerMBean

Tests whether the list of timer notifications is empty.

Specified by:

isEmpty in interface TimerMBean

Following copied from interface: javax.management.timer.TimerMBean

Returns:

true if the list of timer notifications is empty, false otherwise.

getNotificationInfo

public MBeanNotificationInfo[] getNotificationInfo()

Description copied from class: NotificationBroadcasterSupport

Returns a NotificationInfo object contaning the name of the Java class of the notification and the notification types sent.

Overrides:

getNotificationInfo in class NotificationBroadcasterSupport