Timer (Java SE 15 & JDK 15) (original) (raw)

All Implemented Interfaces:

[MBeanRegistration](../MBeanRegistration.html "interface in javax.management"), [NotificationBroadcaster](../NotificationBroadcaster.html "interface in javax.management"), [NotificationEmitter](../NotificationEmitter.html "interface in javax.management"), [TimerMBean](TimerMBean.html "interface in javax.management.timer")

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. When sending timer notifications, the timer updates the notification sequence number irrespective of the notification type.
  2. 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.
  3. The default behavior 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.
  4. 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

Fields

Modifier and Type Field Description
static long ONE_DAY Number of milliseconds in one day.
static long ONE_HOUR Number of milliseconds in one hour.
static long ONE_MINUTE Number of milliseconds in one minute.
static long ONE_SECOND Number of milliseconds in one second.
static long ONE_WEEK Number of milliseconds in one week.

Constructors

Constructor Description
Timer() Default constructor.
Modifier and Type Method Description
Integer addNotification​(String type,String message,Object userData,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 occurrences.
Integer addNotification​(String type,String message,Object userData,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 occurrences.
Integer addNotification​(String type,String message,Object userData,Date date, long period, long nbOccurences) 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 occurrences.
Integer addNotification​(String type,String message,Object userData,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 occurrences.
Vector<Integer> getAllNotificationIDs() Gets all timer notification identifiers registered into the list of notifications.
Date getDate​(Integer id) Gets a copy of the date associated to a timer notification.
Boolean getFixedRate​(Integer id) Gets a copy of the flag indicating whether a periodic notification is executed at fixed-delay or at fixed-rate.
int getNbNotifications() Gets the number of timer notifications registered into the list of notifications.
Long getNbOccurences​(Integer id) Gets a copy of the remaining number of occurrences associated to a timer notification.
Vector<Integer> getNotificationIDs​(String type) Gets all the identifiers of timer notifications corresponding to the specified type.
String getNotificationMessage​(Integer id) Gets the timer notification detailed message corresponding to the specified identifier.
String getNotificationType​(Integer id) Gets the timer notification type corresponding to the specified identifier.
Object getNotificationUserData​(Integer id) Gets the timer notification user data object corresponding to the specified identifier.
Long getPeriod​(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 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 preDeregister() Allows the timer MBean to perform any operations it needs before being unregistered by the MBean server.
ObjectName preRegister​(MBeanServer server,ObjectName name) Allows the timer 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​(Integer id) 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 declared in class java.lang.Object

[clone](../../../../java.base/java/lang/Object.html#clone%28%29), [equals](../../../../java.base/java/lang/Object.html#equals%28java.lang.Object%29), [finalize](../../../../java.base/java/lang/Object.html#finalize%28%29), [getClass](../../../../java.base/java/lang/Object.html#getClass%28%29), [hashCode](../../../../java.base/java/lang/Object.html#hashCode%28%29), [notify](../../../../java.base/java/lang/Object.html#notify%28%29), [notifyAll](../../../../java.base/java/lang/Object.html#notifyAll%28%29), [toString](../../../../java.base/java/lang/Object.html#toString%28%29), [wait](../../../../java.base/java/lang/Object.html#wait%28%29), [wait](../../../../java.base/java/lang/Object.html#wait%28long%29), [wait](../../../../java.base/java/lang/Object.html#wait%28long,int%29)