Class Timer
- All Implemented Interfaces:
MBeanRegistration
,NotificationBroadcaster
,NotificationEmitter
,TimerMBean
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:
- When sending timer notifications, the timer updates the notification sequence number irrespective of the notification type.
- 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. - The default behavior for periodic notifications is fixed-delay execution, as
specified in
Timer
. In order to use fixed-rate execution, use the overloadedaddNotification(String, String, Object, Date, long, long, boolean)
method. - 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
.
- Since:
- 1.5
-
Field Summary
Modifier and TypeFieldDescriptionstatic final long
Number of milliseconds in one day.static final long
Number of milliseconds in one hour.static final long
Number of milliseconds in one minute.static final long
Number of milliseconds in one second.static final long
Number of milliseconds in one week. -
Constructor Summary
-
Method Summary
Modifier and TypeMethodDescriptionaddNotification
(String type, String message, Object userData, Date date) Creates a new timer notification with the specifiedtype
,message
anduserData
and inserts it into the list of notifications with a given date and a null period and number of occurrences.addNotification
(String type, String message, Object userData, Date date, long period) Creates a new timer notification with the specifiedtype
,message
anduserData
and inserts it into the list of notifications with a given date and period and a null number of occurrences.addNotification
(String type, String message, Object userData, Date date, long period, long nbOccurences) Creates a new timer notification with the specifiedtype
,message
anduserData
and inserts it into the list of notifications with a given date, period and number of occurrences.addNotification
(String type, String message, Object userData, Date date, long period, long nbOccurences, boolean fixedRate) Creates a new timer notification with the specifiedtype
,message
anduserData
and inserts it into the list of notifications with a given date, period and number of occurrences.Gets all timer notification identifiers registered into the list of notifications.Gets a copy of the date associated to a timer notification.getFixedRate
(Integer id) Gets a copy of the flag indicating whether a periodic notification is executed at fixed-delay or at fixed-rate.int
Gets the number of timer notifications registered into the list of notifications.Gets a copy of the remaining number of occurrences associated to a timer notification.getNotificationIDs
(String type) Gets all the identifiers of timer notifications corresponding to the specified type.Returns an array indicating, for each notification this MBean may send, the name of the Java class of the notification and the notification type.Gets the timer notification detailed message corresponding to the specified identifier.Gets the timer notification type corresponding to the specified identifier.Gets the timer notification user data object corresponding to the specified identifier.Gets a copy of the period (in milliseconds) associated to a timer notification.boolean
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
Allows the timer MBean to perform any operations needed after having been unregistered by the MBean server.void
postRegister
(Boolean registrationDone) Allows the timer MBean to perform any operations needed after having been registered in the MBean server or after the registration has failed.void
Allows the timer MBean to perform any operations it needs before being unregistered by the MBean server.preRegister
(MBeanServer server, ObjectName name) Allows the timer MBean to perform any operations it needs before being registered in the MBean server.void
Removes all the timer notifications from the list of notifications and resets the counter used to update the timer notification identifiers.void
Removes the timer notification corresponding to the specified identifier from the list of notifications.void
removeNotifications
(String type) Removes all the timer notifications corresponding to the specified type from the list of notifications.void
setSendPastNotifications
(boolean value) 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
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Field Details
-
ONE_SECOND
public static final long ONE_SECONDNumber of milliseconds in one second. Useful constant for theaddNotification
method.- See Also:
-
ONE_MINUTE
public static final long ONE_MINUTENumber of milliseconds in one minute. Useful constant for theaddNotification
method.- See Also:
-
ONE_HOUR
public static final long ONE_HOURNumber of milliseconds in one hour. Useful constant for theaddNotification
method.- See Also:
-
ONE_DAY
public static final long ONE_DAYNumber of milliseconds in one day. Useful constant for theaddNotification
method.- See Also:
-
ONE_WEEK
public static final long ONE_WEEKNumber of milliseconds in one week. Useful constant for theaddNotification
method.- See Also:
-
-
Constructor Details
-
Timer
public Timer()Default constructor.
-
-
Method Details
-
preRegister
Allows the timer MBean to perform any operations it needs before being registered in the MBean server.Not used in this context.
- Specified by:
preRegister
in interfaceMBeanRegistration
- Parameters:
server
- The MBean server in which the timer MBean will be registered.name
- The object name of the timer MBean.- Returns:
- The name of the timer MBean registered.
- Throws:
Exception
- if something goes wrong
-
postRegister
Allows the timer 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 interfaceMBeanRegistration
- 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
Allows the timer MBean to perform any operations it needs before being unregistered by the MBean server.Stops the timer.
- Specified by:
preDeregister
in interfaceMBeanRegistration
- Throws:
Exception
- if something goes wrong
-
postDeregister
public void postDeregister()Allows the timer MBean to perform any operations needed after having been unregistered by the MBean server.Not used in this context.
- Specified by:
postDeregister
in interfaceMBeanRegistration
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getNotificationInfo
Description copied from interface:NotificationBroadcaster
Returns an array indicating, for each notification this MBean may send, the name of the Java class of the notification and the notification type.
It is not illegal for the MBean to send notifications not described in this array. However, some clients of the MBean server may depend on the array being complete for their correct functioning.
- Specified by:
getNotificationInfo
in interfaceNotificationBroadcaster
- Overrides:
getNotificationInfo
in classNotificationBroadcasterSupport
- Returns:
- the array of possible notifications.
-
start
public void start()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 occurrences. 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 interfaceTimerMBean
-
stop
-
addNotification
public Integer addNotification(String type, String message, Object userData, Date date, long period, long nbOccurences, boolean fixedRate) throws IllegalArgumentException Creates a new timer notification with the specifiedtype
,message
anduserData
and inserts it into the list of notifications with a given date, period and number of occurrences.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 occurrences 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 interfaceTimerMBean
- 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
- Iftrue
and if the notification is periodic, the notification is scheduled with a fixed-rate execution scheme. Iffalse
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:
IllegalArgumentException
- The date isnull
or the period or the number of occurrences is negative.- See Also:
-
addNotification
public Integer addNotification(String type, String message, Object userData, Date date, long period, long nbOccurences) throws IllegalArgumentException Creates a new timer notification with the specifiedtype
,message
anduserData
and inserts it into the list of notifications with a given date, period and number of occurrences.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 occurrences cannot be updated.
In the case of a periodic notification, uses a fixed-delay execution scheme, as specified in
Timer
. In order to use a fixed-rate execution scheme, useaddNotification(String, String, Object, Date, long, long, boolean)
instead.- Specified by:
addNotification
in interfaceTimerMBean
- 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.- Returns:
- The identifier of the new created timer notification.
- Throws:
IllegalArgumentException
- The date isnull
or the period or the number of occurrences is negative.- See Also:
-
addNotification
public Integer addNotification(String type, String message, Object userData, Date date, long period) throws IllegalArgumentException Creates a new timer notification with the specifiedtype
,message
anduserData
and inserts it into the list of notifications with a given date and period and a null number of occurrences.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, useaddNotification(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 interfaceTimerMBean
- 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:
IllegalArgumentException
- The date isnull
or the period is negative.
-
addNotification
public Integer addNotification(String type, String message, Object userData, Date date) throws IllegalArgumentException Creates a new timer notification with the specifiedtype
,message
anduserData
and inserts it into the list of notifications with a given date and a null period and number of occurrences.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 interfaceTimerMBean
- 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:
IllegalArgumentException
- The date isnull
.
-
removeNotification
Removes the timer notification corresponding to the specified identifier from the list of notifications.- Specified by:
removeNotification
in interfaceTimerMBean
- 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
Removes all the timer notifications corresponding to the specified type from the list of notifications.- Specified by:
removeNotifications
in interfaceTimerMBean
- 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()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 interfaceTimerMBean
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getNbNotifications
public int getNbNotifications()Gets the number of timer notifications registered into the list of notifications.- Specified by:
getNbNotifications
in interfaceTimerMBean
- Returns:
- The number of timer notifications.
-
getAllNotificationIDs
Gets all timer notification identifiers registered into the list of notifications.- Specified by:
getAllNotificationIDs
in interfaceTimerMBean
- 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
Gets all the identifiers of timer notifications corresponding to the specified type.- Specified by:
getNotificationIDs
in interfaceTimerMBean
- Parameters:
type
- The timer notification type.- Returns:
- A vector of
Integer
objects containing all the identifiers of timer notifications with the specifiedtype
.
The vector is empty if there is no timer notifications registered for this timer MBean with the specifiedtype
.
-
getNotificationType
Gets the timer notification type corresponding to the specified identifier.- Specified by:
getNotificationType
in interfaceTimerMBean
- 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
Gets the timer notification detailed message corresponding to the specified identifier.- Specified by:
getNotificationMessage
in interfaceTimerMBean
- 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.
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getNotificationUserData
Gets the timer notification user data object corresponding to the specified identifier.- Specified by:
getNotificationUserData
in interfaceTimerMBean
- 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.
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getDate
Gets a copy of the date associated to a timer notification.- Specified by:
getDate
in interfaceTimerMBean
- 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.
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getPeriod
Gets a copy of the period (in milliseconds) associated to a timer notification.- Specified by:
getPeriod
in interfaceTimerMBean
- 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.
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getNbOccurences
Gets a copy of the remaining number of occurrences associated to a timer notification.- Specified by:
getNbOccurences
in interfaceTimerMBean
- Parameters:
id
- The timer notification identifier.- Returns:
- A copy of the remaining number of occurrences or null if the identifier is not mapped to any timer notification registered for this timer MBean.
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getFixedRate
Gets a copy of the flag indicating whether a periodic notification is executed at fixed-delay or at fixed-rate.- Specified by:
getFixedRate
in interfaceTimerMBean
- Parameters:
id
- The timer notification identifier.- Returns:
- A copy of the flag indicating whether a periodic notification is executed at fixed-delay or at fixed-rate.
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getSendPastNotifications
public boolean getSendPastNotifications()Gets the flag indicating whether or not the timer sends past notifications.
The default value of the past notifications sending on/off flag isfalse
.- Specified by:
getSendPastNotifications
in interfaceTimerMBean
- Returns:
- The past notifications sending on/off flag value.
- See Also:
-
setSendPastNotifications
public void setSendPastNotifications(boolean value) Sets the flag indicating whether the timer sends past notifications or not.
The default value of the past notifications sending on/off flag isfalse
.- Specified by:
setSendPastNotifications
in interfaceTimerMBean
- Parameters:
value
- The past notifications sending on/off flag value.- See Also:
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isActive
public boolean isActive()Tests whether the timer MBean is active. A timer MBean is marked active when thestart
method is called. It becomes inactive when thestop
method is called.
The default value of the active on/off flag isfalse
.- Specified by:
isActive
in interfaceTimerMBean
- Returns:
true
if the timer MBean is active,false
otherwise.
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isEmpty
public boolean isEmpty()Tests whether the list of timer notifications is empty.- Specified by:
isEmpty
in interfaceTimerMBean
- Returns:
true
if the list of timer notifications is empty,false
otherwise.
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