/* * @(#)Timer.java 4.58 04/04/13 * * Copyright 2004 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ package javax.management.timer; // java imports // import java.util.Date; import java.util.Enumeration; import java.util.Hashtable; import java.util.Iterator; import java.util.Set; import java.util.TreeSet; import java.util.Vector; // jmx imports // import javax.management.MBeanNotificationInfo; import javax.management.MBeanRegistration; import javax.management.MBeanServer; import javax.management.NotificationBroadcasterSupport; import javax.management.ObjectName; import javax.management.InstanceNotFoundException; import com.sun.jmx.trace.Trace; /** * * 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 behavior for periodic notifications is fixed-delay execution, as * specified in {@link java.util.Timer}. In order to use fixed-rate execution, use the * overloaded {@link #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 {@link NotificationBroadcasterSupport}. *
* * @version 4.58 04/13/04 * @author Sun Microsystems, Inc * * @since 1.5 */ public class Timer extends NotificationBroadcasterSupport implements TimerMBean, MBeanRegistration { /* * ------------------------------------------ * PUBLIC VARIABLES * ------------------------------------------ */ /** * Number of milliseconds in one second. * Useful constant for the addNotification method. */ public static final long ONE_SECOND = 1000; /** * Number of milliseconds in one minute. * Useful constant for the addNotification method. */ public static final long ONE_MINUTE = 60*ONE_SECOND; /** * Number of milliseconds in one hour. * Useful constant for the addNotification method. */ public static final long ONE_HOUR = 60*ONE_MINUTE; /** * Number of milliseconds in one day. * Useful constant for the addNotification method. */ public static final long ONE_DAY = 24*ONE_HOUR; /** * Number of milliseconds in one week. * Useful constant for the addNotification method. */ public static final long ONE_WEEK = 7*ONE_DAY; // TRACES & DEBUG //--------------- boolean isTraceOn() { return Trace.isSelected(Trace.LEVEL_TRACE, Trace.INFO_TIMER); } void trace(String clz, String func, String info) { Trace.send(Trace.LEVEL_TRACE, Trace.INFO_TIMER, clz, func, info); } void trace(String func, String info) { trace(dbgTag, func, info); } boolean isDebugOn() { return Trace.isSelected(Trace.LEVEL_DEBUG, Trace.INFO_TIMER); } void debug(String clz, String func, String info) { Trace.send(Trace.LEVEL_DEBUG, Trace.INFO_TIMER, clz, func, info); } void debug(String func, String info) { debug(dbgTag, func, info); } /* * ------------------------------------------ * PRIVATE VARIABLES * ------------------------------------------ */ private static final String dbgTag = "Timer"; /** * Table containing all the timer notifications of this timer, * with the associated date, period and number of occurrences. */ private Hashtable timerTable = new Hashtable(); /** * Past notifications sending on/off flag value. * This attribute is used to specify if the timer has to send past notifications after start. *
The default value is set to false. */ private boolean sendPastNotifications = false; /** * Timer state. * The default value is set to false. */ private transient boolean isActive = false; /** * Timer sequence number. * The default value is set to 0. */ private transient long sequenceNumber = 0; // Flags needed to keep the indexes of the objects in the array. // private static final int TIMER_NOTIF_INDEX = 0; private static final int TIMER_DATE_INDEX = 1; private static final int TIMER_PERIOD_INDEX = 2; private static final int TIMER_NB_OCCUR_INDEX = 3; private static final int ALARM_CLOCK_INDEX = 4; private static final int FIXED_RATE_INDEX = 5; /** * The notification counter ID. * Used to keep the max key value inserted into the timer table. */ private int counterID = 0; private java.util.Timer timer; /* * ------------------------------------------ * CONSTRUCTORS * ------------------------------------------ */ /** * Default constructor. */ public Timer() { } /* * ------------------------------------------ * PUBLIC METHODS * ------------------------------------------ */ /** * Allows the timer MBean to perform any operations it needs before being registered * in the MBean server. *

* Not used in this context. * * @param server The MBean server in which the timer MBean will be registered. * @param name The object name of the timer MBean. * * @return The name of the timer MBean registered. * * @exception java.lang.Exception */ public ObjectName preRegister(MBeanServer server, ObjectName name) throws java.lang.Exception { return name; } /** * 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. */ public void postRegister (Boolean registrationDone) { } /** * Allows the timer MBean to perform any operations it needs before being unregistered * by the MBean server. *

* Stops the timer. * * @exception java.lang.Exception */ public void preDeregister() throws java.lang.Exception { if (isTraceOn()) { trace("preDeregister", "stop the timer"); } // Stop the timer. // stop(); } /** * Allows the timer MBean to perform any operations needed after having been * unregistered by the MBean server. *

* Not used in this context. */ public void postDeregister() { } /* * This overrides the method in NotificationBroadcasterSupport. * Return the MBeanNotificationInfo[] array for this MBean. * The returned array has one element to indicate that the MBean * can emit TimerNotification. The array of type strings * associated with this entry is a snapshot of the current types * that were given to addNotification. */ public synchronized MBeanNotificationInfo[] getNotificationInfo() { Set/**/ notifTypes = new TreeSet(); for (Iterator it = timerTable.values().iterator(); it.hasNext(); ) { Object[] entry = (Object[]) it.next(); TimerNotification notif = (TimerNotification) entry[TIMER_NOTIF_INDEX]; notifTypes.add(notif.getType()); } String[] notifTypesArray = (String[]) notifTypes.toArray(new String[0]); return new MBeanNotificationInfo[] { new MBeanNotificationInfo(notifTypesArray, TimerNotification.class.getName(), "Notification sent by Timer MBean") }; } /** * 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. */ public synchronized void start() { if (isTraceOn()) { trace("start", "starting the timer"); } // Start the TimerAlarmClock. // if (isActive == false) { timer = new java.util.Timer(); TimerAlarmClock alarmClock; Object[] obj; Date date; Date currentDate = new Date(); // Send or not past notifications depending on the flag. // Update the date and the number of occurrences of past notifications // to make them later than the current date. // sendPastNotifications(currentDate, sendPastNotifications); // Update and start all the TimerAlarmClocks. // Here, all the notifications in the timer table are later than the current date. // Enumeration e = timerTable.elements(); while (e.hasMoreElements()) { obj = (Object[])e.nextElement(); // Retrieve the date notification and the TimerAlarmClock. // date = (Date)obj[TIMER_DATE_INDEX]; // Update all the TimerAlarmClock timeouts and start them. // boolean fixedRate = ((Boolean)obj[FIXED_RATE_INDEX]).booleanValue(); if (fixedRate) { alarmClock = new TimerAlarmClock(this, date); obj[ALARM_CLOCK_INDEX] = (Object)alarmClock; timer.schedule(alarmClock, alarmClock.next); } else { alarmClock = new TimerAlarmClock(this, (date.getTime() - currentDate.getTime())); obj[ALARM_CLOCK_INDEX] = (Object)alarmClock; timer.schedule(alarmClock, alarmClock.timeout); } } // Set the state to ON. // isActive = true; if (isTraceOn()) { trace("start", "timer started"); } } else { if (isTraceOn()) { trace("start", "the timer is already activated"); } } } /** * Stops the timer. */ public synchronized void stop() { if (isTraceOn()) { trace("stop", "stoping the timer"); } // Stop the TimerAlarmClock. // if (isActive == true) { TimerAlarmClock alarmClock; Object[] obj; Enumeration e = timerTable.elements(); while (e.hasMoreElements()) { obj = (Object[])e.nextElement(); // Stop all the TimerAlarmClock. // alarmClock = (TimerAlarmClock)obj[ALARM_CLOCK_INDEX]; if (alarmClock != null) { // alarmClock.interrupt(); // try { // // Wait until the thread die. // // // alarmClock.join(); // } catch (InterruptedException ex) { // // Ignore... // } // // Remove the reference on the TimerAlarmClock. // // alarmClock.cancel(); alarmClock = null; } } timer.cancel(); // Set the state to OFF. // isActive = false; if (isTraceOn()) { trace("stop", "timer stopped"); } } else { if (isTraceOn()) { trace("stop", "the timer is already deactivated"); } } } /** * 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. *

* 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 {@link java.util.Timer}. * * @param type The timer notification type. * @param message The timer notification detailed message. * @param userData The timer notification user data object. * @param date The date when the notification occurs. * @param period The period of the timer notification (in milliseconds). * @param nbOccurences The total number the timer notification will be emitted. * @param 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. * * @return The identifier of the new created timer notification. * * @exception java.lang.IllegalArgumentException The period or the number of occurrences is negative * * @see #addNotification(String, String, Object, Date, long, long) */ // NPCTE fix for bugId 4464388, esc 0, MR, to be added after modification of jmx spec // public synchronized Integer addNotification(String type, String message, Serializable userData, // Date date, long period, long nbOccurences) // end of NPCTE fix for bugId 4464388 public synchronized Integer addNotification(String type, String message, Object userData, Date date, long period, long nbOccurences, boolean fixedRate) throws java.lang.IllegalArgumentException { if (date == null) { throw new java.lang.IllegalArgumentException("Timer notification date cannot be null."); } // Check that all the timer notification attributes are valid. // // Invalid timer period value exception: // Check that the period and the nbOccurences are POSITIVE VALUES. // if ((period < 0) || (nbOccurences < 0)) { throw new java.lang.IllegalArgumentException("Negative values for the periodicity"); } Date currentDate = new Date(); // Update the date if it is before the current date. // if (currentDate.after(date)) { date.setTime(currentDate.getTime()); if (isTraceOn()) { trace("addNotification", "update timer notification to add with:" + "\n\tNotification date = " + date); } } // Create and add the timer notification into the timer table. // Integer notifID = null; notifID = new Integer(++counterID); // The sequenceNumber and the timeStamp attributes are updated // when the notification is emitted by the timer. // TimerNotification notif = new TimerNotification(type, this, 0, 0, message, notifID); notif.setUserData(userData); Object[] obj = new Object[6]; TimerAlarmClock alarmClock; if (fixedRate) { alarmClock = new TimerAlarmClock(this, date); } else { alarmClock = new TimerAlarmClock(this, (date.getTime() - currentDate.getTime())); } // Fix bug 00417.B // The date registered into the timer is a clone from the date parameter. // Date d = new Date(date.getTime()); obj[TIMER_NOTIF_INDEX] = (Object)notif; obj[TIMER_DATE_INDEX] = (Object)d; obj[TIMER_PERIOD_INDEX] = (Object) new Long(period); obj[TIMER_NB_OCCUR_INDEX] = (Object) new Long(nbOccurences); obj[ALARM_CLOCK_INDEX] = (Object)alarmClock; obj[FIXED_RATE_INDEX] = new Boolean(fixedRate); if (isTraceOn()) { trace("addNotification", "adding timer notification:" + "\n\tNotification source = " + notif.getSource() + "\n\tNotification type = " + notif.getType() + "\n\tNotification ID = " + notifID + "\n\tNotification date = " + d + "\n\tNotification period = " + period + "\n\tNotification nb of occurrences = " + nbOccurences + "\n\tNotification executes at fixed rate = " + fixedRate); } timerTable.put(notifID, obj); // Update and start the TimerAlarmClock. // if (isActive == true) { if (fixedRate) { timer.schedule(alarmClock, alarmClock.next); } else { timer.schedule(alarmClock, alarmClock.timeout); } } if (isTraceOn()) { trace("addNotification", "timer notification added"); } return notifID; } /** * 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. *

* 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 * {@link java.util.Timer}. In order to use a fixed-rate execution scheme, use * {@link #addNotification(String, String, Object, Date, long, long, boolean)} instead. * * @param type The timer notification type. * @param message The timer notification detailed message. * @param userData The timer notification user data object. * @param date The date when the notification occurs. * @param period The period of the timer notification (in milliseconds). * @param nbOccurences The total number the timer notification will be emitted. * * @return The identifier of the new created timer notification. * * @exception java.lang.IllegalArgumentException The period or the number of occurrences is negative * * @see #addNotification(String, String, Object, Date, long, long, boolean) */ // NPCTE fix for bugId 4464388, esc 0, MR , to be added after modification of jmx spec // public synchronized Integer addNotification(String type, String message, Serializable userData, // Date date, long period) // end of NPCTE fix for bugId 4464388 */ public synchronized Integer addNotification(String type, String message, Object userData, Date date, long period, long nbOccurences) throws java.lang.IllegalArgumentException { return addNotification(type, message, userData, date, period, nbOccurences, false); } /** * 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. *

* The timer notification will repeat continuously using the timer period using a fixed-delay * execution scheme, as specified in {@link java.util.Timer}. In order to use a fixed-rate * execution scheme, use {@link #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. * * @param type The timer notification type. * @param message The timer notification detailed message. * @param userData The timer notification user data object. * @param date The date when the notification occurs. * @param period The period of the timer notification (in milliseconds). * * @return The identifier of the new created timer notification. * * @exception java.lang.IllegalArgumentException The period is negative or * the date notification is before the current date. */ // NPCTE fix for bugId 4464388, esc 0, MR , to be added after modification of jmx spec // public synchronized Integer addNotification(String type, String message, Serializable userData, // Date date, long period) // end of NPCTE fix for bugId 4464388 */ public synchronized Integer addNotification(String type, String message, Object userData, Date date, long period) throws java.lang.IllegalArgumentException { return (addNotification(type, message, userData, date, period, 0)); } /** * 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. *

* 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. * * @param type The timer notification type. * @param message The timer notification detailed message. * @param userData The timer notification user data object. * @param date The date when the notification occurs. * * @return The identifier of the new created timer notification. * * @exception java.lang.IllegalArgumentException The date notification is before the current date. */ // NPCTE fix for bugId 4464388, esc 0, MR, to be added after modification of jmx spec // public synchronized Integer addNotification(String type, String message, Serializable userData, Date date) // throws java.lang.IllegalArgumentException { // end of NPCTE fix for bugId 4464388 public synchronized Integer addNotification(String type, String message, Object userData, Date date) throws java.lang.IllegalArgumentException { return (addNotification(type, message, userData, date, 0, 0)); } /** * Removes the timer notification corresponding to the specified identifier from the list of notifications. * * @param id The timer notification identifier. * * @exception InstanceNotFoundException The specified identifier does not correspond to any timer notification * in the list of notifications of this timer MBean. */ public synchronized void removeNotification(Integer id) throws InstanceNotFoundException { // Check that the notification to remove is effectively in the timer table. // if (timerTable.containsKey(id) == false) { throw new InstanceNotFoundException("Timer notification to remove not in the list of notifications"); } // Stop the TimerAlarmClock. // Object[] obj = (Object[])timerTable.get(id); TimerAlarmClock alarmClock = (TimerAlarmClock)obj[ALARM_CLOCK_INDEX]; if (alarmClock != null) { // alarmClock.interrupt(); // try { // // Wait until the thread die. // // // alarmClock.join(); // } catch (InterruptedException e) { // // Ignore... // } // // Remove the reference on the TimerAlarmClock. // // alarmClock.cancel(); alarmClock = null; } // Remove the timer notification from the timer table. // if (isTraceOn()) { trace("removeNotification", "removing timer notification:" + "\n\tNotification source = " + ((TimerNotification)obj[TIMER_NOTIF_INDEX]).getSource() + "\n\tNotification type = " + ((TimerNotification)obj[TIMER_NOTIF_INDEX]).getType() + "\n\tNotification ID = " + ((TimerNotification)obj[TIMER_NOTIF_INDEX]).getNotificationID() + "\n\tNotification date = " + obj[TIMER_DATE_INDEX] + "\n\tNotification period = " + obj[TIMER_PERIOD_INDEX] + "\n\tNotification nb of occurrences = " + obj[TIMER_NB_OCCUR_INDEX] + "\n\tNotification executes at fixed rate = " + obj[FIXED_RATE_INDEX]); } timerTable.remove(id); if (isTraceOn()) { trace("removeNotification", "timer notification removed"); } } /** * Removes all the timer notifications corresponding to the specified type from the list of notifications. * * @param type The timer notification type. * * @exception InstanceNotFoundException The specified type does not correspond to any timer notification * in the list of notifications of this timer MBean. */ public synchronized void removeNotifications(String type) throws InstanceNotFoundException { TimerNotification notif; Integer id; TimerAlarmClock alarmClock; Object[] obj; Vector v = getNotificationIDs(type); // Check that the notification to remove is effectively in the timer table. // if (v.isEmpty()) { throw new InstanceNotFoundException("Timer notifications to remove not in the list of notifications"); } Enumeration e = v.elements(); while (e.hasMoreElements()) { notif = (TimerNotification)e.nextElement(); id = notif.getNotificationID(); obj = (Object[])timerTable.get(id); timerTable.remove(id); alarmClock = (TimerAlarmClock)obj[ALARM_CLOCK_INDEX]; if (alarmClock != null) { alarmClock.cancel(); } } } /** * Removes all the timer notifications from the list of notifications * and resets the counter used to update the timer notification identifiers. */ public synchronized void removeAllNotifications() { Object[] obj; TimerAlarmClock alarmClock; Enumeration e = timerTable.elements(); while (e.hasMoreElements()) { obj = (Object[])e.nextElement(); // Stop the TimerAlarmClock. // alarmClock = (TimerAlarmClock)obj[ALARM_CLOCK_INDEX]; // if (alarmClock != null) { // alarmClock.interrupt(); // try { // // Wait until the thread die. // // // alarmClock.join(); // } catch (InterruptedException ex) { // // Ignore... // } // Remove the reference on the TimerAlarmClock. // // } alarmClock.cancel(); alarmClock = null; } // Remove all the timer notifications from the timer table. // if (isTraceOn()) { trace("removeAllNotifications", "removing all timer notifications"); } timerTable.clear(); if (isTraceOn()) { trace("removeAllNotifications", "all timer notifications removed"); } // Reset the counterID. // counterID = 0; if (isTraceOn()) { trace("removeAllNotifications", "timer notification counter ID resetted"); } } // GETTERS AND SETTERS //-------------------- /** * Gets the number of timer notifications registered into the list of notifications. * * @return The number of timer notifications. */ public int getNbNotifications() { return timerTable.size(); } /** * Gets all timer notification identifiers registered into the list of notifications. * * @return 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. */ public synchronized Vector getAllNotificationIDs() { Vector v = new Vector(); Enumeration e = timerTable.keys(); while (e.hasMoreElements()) { v.addElement((Integer)e.nextElement()); } return v; } /** * Gets all the identifiers of timer notifications corresponding to the specified type. * * @param type The timer notification type. * * @return 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. */ public synchronized Vector getNotificationIDs(String type) { Object[] obj; String s; Vector v = new Vector(); Enumeration e = timerTable.elements(); // If the specified type is null, retreive all the timer notificatiosn which type is null. // if (type == null) { while (e.hasMoreElements()) { obj = (Object[])e.nextElement(); s = ((TimerNotification)obj[TIMER_NOTIF_INDEX]).getType(); if (s == null) { v.addElement((TimerNotification)obj[TIMER_NOTIF_INDEX]); } } } else { while (e.hasMoreElements()) { obj = (Object[])e.nextElement(); s = ((TimerNotification)obj[TIMER_NOTIF_INDEX]).getType(); if (type.equals(s)) { v.addElement((TimerNotification)obj[TIMER_NOTIF_INDEX]); } } } return v; } /** * Gets the timer notification type corresponding to the specified identifier. * * @param id The timer notification identifier. * * @return The timer notification type or null if the identifier is not mapped to any * timer notification registered for this timer MBean. */ public String getNotificationType(Integer id) { Object[] obj = (Object[])timerTable.get(id); if (obj != null) { return ( (String)((TimerNotification)obj[TIMER_NOTIF_INDEX]).getType() ); } return null; } /** * Gets the timer notification detailed message corresponding to the specified identifier. * * @param id The timer notification identifier. * * @return The timer notification detailed message or null if the identifier is not mapped to any * timer notification registered for this timer MBean. */ public String getNotificationMessage(Integer id) { Object[] obj = (Object[])timerTable.get(id); if (obj != null) { return ( (String)((TimerNotification)obj[TIMER_NOTIF_INDEX]).getMessage() ); } return null; } /** * Gets the timer notification user data object corresponding to the specified identifier. * * @param id The timer notification identifier. * * @return The timer notification user data object or null if the identifier is not mapped to any * timer notification registered for this timer MBean. */ // NPCTE fix for bugId 4464388, esc 0, MR, 03 sept 2001, to be added after modification of jmx spec //public Serializable getNotificationUserData(Integer id) { // end of NPCTE fix for bugId 4464388 public Object getNotificationUserData(Integer id) { Object[] obj = (Object[])timerTable.get(id); if (obj != null) { return ( ((TimerNotification)obj[TIMER_NOTIF_INDEX]).getUserData() ); } return null; } /** * Gets a copy of the date associated to a timer notification. * * @param id The timer notification identifier. * * @return A copy of the date or null if the identifier is not mapped to any * timer notification registered for this timer MBean. */ public Date getDate(Integer id) { Object[] obj = (Object[])timerTable.get(id); if (obj != null) { Date date = (Date)obj[TIMER_DATE_INDEX]; return (new Date(date.getTime())); } return null; } /** * Gets a copy of the period (in milliseconds) associated to a timer notification. * * @param id The timer notification identifier. * * @return A copy of the period or null if the identifier is not mapped to any * timer notification registered for this timer MBean. */ public Long getPeriod(Integer id) { Object[] obj = (Object[])timerTable.get(id); if (obj != null) { Long period = (Long)obj[TIMER_PERIOD_INDEX]; return (new Long(period.longValue())); } return null; } /** * Gets a copy of the remaining number of occurrences associated to a timer notification. * * @param id The timer notification identifier. * * @return 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. */ public Long getNbOccurences(Integer id) { Object[] obj = (Object[])timerTable.get(id); if (obj != null) { Long nbOccurences = (Long)obj[TIMER_NB_OCCUR_INDEX]; return (new Long(nbOccurences.longValue())); } return null; } /** * Gets a copy of the flag indicating whether a periodic notification is * executed at fixed-delay or at fixed-rate. * * @param id The timer notification identifier. * * @return A copy of the flag indicating whether a periodic notification is * executed at fixed-delay or at fixed-rate. */ public Boolean getFixedRate(Integer id) { Object[] obj = (Object[])timerTable.get(id); if (obj != null) { Boolean fixedRate = (Boolean)obj[FIXED_RATE_INDEX]; return (new Boolean(fixedRate.booleanValue())); } return null; } /** * Gets the flag indicating whether or not the timer sends past notifications. *
The default value of the past notifications sending on/off flag is false. * * @return The past notifications sending on/off flag value. * * @see #setSendPastNotifications */ public boolean getSendPastNotifications() { return sendPastNotifications; } /** * Sets the flag indicating whether the timer sends past notifications or not. *
The default value of the past notifications sending on/off flag is false. * * @param value The past notifications sending on/off flag value. * * @see #getSendPastNotifications */ public void setSendPastNotifications(boolean value) { sendPastNotifications = value; } /** * Tests whether the timer MBean is active. * A timer MBean is marked active when the {@link #start start} method is called. * It becomes inactive when the {@link #stop stop} method is called. *
The default value of the active on/off flag is false. * * @return true if the timer MBean is active, false otherwise. */ public boolean isActive() { return isActive; } /** * Tests whether the list of timer notifications is empty. * * @return true if the list of timer notifications is empty, false otherwise. */ public boolean isEmpty() { return (timerTable.isEmpty()); } /* * ------------------------------------------ * PRIVATE METHODS * ------------------------------------------ */ /** * Sends or not past notifications depending on the specified flag. * * @param currentDate The current date. * @param currentFlag The flag indicating if past notifications must be sent or not. */ private synchronized void sendPastNotifications(Date currentDate, boolean currentFlag) { TimerNotification notif; Integer notifID; Date date; Object[] obj; Enumeration e = timerTable.elements(); while (e.hasMoreElements()) { obj = (Object[])e.nextElement(); // Retrieve the timer notification and the date notification. // notif = (TimerNotification)obj[TIMER_NOTIF_INDEX]; notifID = notif.getNotificationID(); date = (Date)obj[TIMER_DATE_INDEX]; // Update the timer notification while: // - the timer notification date is earlier than the current date // - the timer notification has not been removed from the timer table. // while ( (currentDate.after(date)) && (timerTable.containsKey(notifID)) ) { if (currentFlag == true) { if (isTraceOn()) { trace("sendPastNotifications", "sending past timer notification:" + "\n\tNotification source = " + notif.getSource() + "\n\tNotification type = " + notif.getType() + "\n\tNotification ID = " + notif.getNotificationID() + "\n\tNotification date = " + date + "\n\tNotification period = " + obj[TIMER_PERIOD_INDEX] + "\n\tNotification nb of occurrences = " + obj[TIMER_NB_OCCUR_INDEX] + "\n\tNotification executes at fixed rate = " + obj[FIXED_RATE_INDEX]); } sendNotification(date, notif); if (isTraceOn()) { trace("sendPastNotifications", "past timer notification sent"); } } // Update the date and the number of occurrences of the timer notification. // updateTimerTable(notif.getNotificationID()); } } } /** * If the timer notification is not periodic, it is removed from the list of notifications. *

* If the timer period of the timer notification has a non null periodicity, * the date of the timer notification is updated by adding the periodicity. * The associated TimerAlarmClock is updated by setting its timeout to the period value. *

* If the timer period has a defined number of occurrences, the timer * notification is updated if the number of occurrences has not yet been reached. * Otherwise it is removed from the list of notifications. * * @param notifID The timer notification identifier to update. */ private synchronized void updateTimerTable(Integer notifID) { // Retrieve the timer notification and the TimerAlarmClock. // Object[] obj = (Object[])timerTable.get(notifID); Date date = (Date)obj[TIMER_DATE_INDEX]; Long period = (Long)obj[TIMER_PERIOD_INDEX]; Long nbOccurences = (Long)obj[TIMER_NB_OCCUR_INDEX]; Boolean fixedRate = (Boolean)obj[FIXED_RATE_INDEX]; TimerAlarmClock alarmClock = (TimerAlarmClock)obj[ALARM_CLOCK_INDEX]; if (period.longValue() != 0) { // Update the date and the number of occurrences of the timer notification // and the TimerAlarmClock time out. // NOTES : // nbOccurences = 0 notifies an infinite periodicity. // nbOccurences = 1 notifies a finite periodicity that has reached its end. // nbOccurences > 1 notifies a finite periodicity that has not yet reached its end. // if ((nbOccurences.longValue() == 0) || (nbOccurences.longValue() > 1)) { date.setTime(date.getTime() + period.longValue()); obj[TIMER_NB_OCCUR_INDEX] = new Long(java.lang.Math.max(0L, (nbOccurences.longValue() - 1))); nbOccurences = (Long)obj[TIMER_NB_OCCUR_INDEX]; if (isActive == true) { if (fixedRate.booleanValue()) { alarmClock = new TimerAlarmClock(this, date); obj[ALARM_CLOCK_INDEX] = (Object)alarmClock; timer.schedule(alarmClock, alarmClock.next); } else { alarmClock = new TimerAlarmClock(this, period.longValue()); obj[ALARM_CLOCK_INDEX] = (Object)alarmClock; timer.schedule(alarmClock, alarmClock.timeout); } } if (isTraceOn()) { TimerNotification notif = (TimerNotification)obj[TIMER_NOTIF_INDEX]; trace("updateTimerTable", "update timer notification with:" + "\n\tNotification source = " + notif.getSource() + "\n\tNotification type = " + notif.getType() + "\n\tNotification ID = " + notifID + "\n\tNotification date = " + date + "\n\tNotification period = " + period + "\n\tNotification nb of occurrences = " + nbOccurences + "\n\tNotification executes at fixed rate = " + fixedRate); } } else { if (alarmClock != null) { // alarmClock.interrupt(); // try { // // Wait until the thread die. // // // alarmClock.join(); // } catch (InterruptedException e) { // // Ignore... // } alarmClock.cancel(); // Remove the reference on the TimerAlarmClock. // alarmClock = null; } timerTable.remove(notifID); } } else { if (alarmClock != null) { // alarmClock.interrupt(); // try { // // Wait until the thread die. // // // alarmClock.join(); // } catch (InterruptedException e) { // // Ignore... // } alarmClock.cancel(); // Remove the reference on the TimerAlarmClock. // alarmClock = null; } timerTable.remove(notifID); } } /* * ------------------------------------------ * PACKAGE METHODS * ------------------------------------------ */ /** * This method is called by the timer each time * the TimerAlarmClock has exceeded its timeout. * * @param notification The TimerAlarmClock notification. */ void notifyAlarmClock(TimerAlarmClockNotification notification) { Object[] obj; TimerNotification timerNotification = null; Date timerDate = null; // Retrieve the timer notification associated to the alarm-clock. // TimerAlarmClock alarmClock = (TimerAlarmClock)notification.getSource(); Enumeration e = timerTable.elements(); while (e.hasMoreElements()) { obj = (Object[])e.nextElement(); if (obj[ALARM_CLOCK_INDEX] == alarmClock) { timerNotification = (TimerNotification)obj[TIMER_NOTIF_INDEX]; timerDate = (Date)obj[TIMER_DATE_INDEX]; break; } } // Notify the timer. // sendNotification(timerDate, timerNotification); // Update the notification and the TimerAlarmClock timeout. // updateTimerTable(timerNotification.getNotificationID()); } /** * This method is used by the timer MBean to update and send a timer * notification to all the listeners registered for this kind of notification. * * @param timeStamp The notification emission date. * @param notification The timer notification to send. */ void sendNotification(Date timeStamp, TimerNotification notification) { if (isTraceOn()) { trace("sendNotification", "sending timer notification:" + "\n\tNotification source = " + notification.getSource() + "\n\tNotification type = " + notification.getType() + "\n\tNotification ID = " + notification.getNotificationID() + "\n\tNotification date = " + timeStamp); } long curSeqNumber; synchronized(this) { sequenceNumber = sequenceNumber + 1; curSeqNumber = sequenceNumber; } synchronized (notification) { notification.setTimeStamp(timeStamp.getTime()); notification.setSequenceNumber(curSeqNumber); this.sendNotification((TimerNotification)notification.cloneTimerNotification()); } if (isTraceOn()) { trace("sendNotification", "timer notification sent"); } } } /** * TimerAlarmClock inner class: * This class provides a simple implementation of an alarm clock MBean. * The aim of this MBean is to set up an alarm which wakes up the timer every timeout (fixed-delay) * or at the specified date (fixed-rate). */ class TimerAlarmClock extends java.util.TimerTask { Timer listener = null; long timeout = 10000; Date next = null; /* * ------------------------------------------ * CONSTRUCTORS * ------------------------------------------ */ public TimerAlarmClock(Timer listener, long timeout) { this.listener = listener; this.timeout = Math.max(0L, timeout); } public TimerAlarmClock(Timer listener, Date next) { this.listener = listener; this.next = next; } /* * ------------------------------------------ * PUBLIC METHODS * ------------------------------------------ */ /** * This method is called by the timer when it is started. */ public void run() { try { //this.sleep(timeout); TimerAlarmClockNotification notif = new TimerAlarmClockNotification(this); listener.notifyAlarmClock(notif); } catch (Exception e) { if (Trace.isSelected(Trace.LEVEL_DEBUG, Trace.INFO_TIMER)) { Trace.send(Trace.LEVEL_DEBUG, Trace.INFO_TIMER, "TimerAlarmClock", "run", "Got an exception when sending a notifiacation: "+e); } } } }