com.antelmann.calendar
Class AtomicTime

java.lang.Object
  com.antelmann.calendar.AtomicTime

All Implemented Interfaces:

TimeSystem

public class AtomicTime
extends Object
implements TimeSystem

works based on an AtomicClock instance adding reliability by using multiple server if one fails.

Author:

Holger Antelmann

See Also:

AtomicClock

Field Summary

Fields inherited from interface com.antelmann.calendar.TimeSystem

systemTime

Constructor Summary

AtomicTime()
immediately activates the instance and schedules updates in the interval given.

AtomicTime(boolean activateNow)
Interval is 24h.

AtomicTime(boolean activateNow, long updateIntervalMillis)
immediately activates the instance and schedules updates in the interval given.

AtomicTime(boolean activateNow, long updateIntervalMillis, Logger logger)

Method Summary

void	activate() activates the embedded timer for automatic updates
long	currentTimeMillis() returns the current time
void	deactivate() deactivates the embedded timer for automatic updates
protected void	finalize()
AtomicClock	getAtomicClock() returns the clock in use
Logger	getLogger() may be null
Set<String>	getServerNames() returned set allows to add/remove server names if required
long	getUpdateIntervalMillis()
boolean	isActivated()
void	setLogger(Logger logger) may be set to null
void	setUpdateIntervalMillis(long updateIntervalMillis) must be called while the instance is deactivated.

Methods inherited from class java.lang.Object

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

Constructor Detail

AtomicTime

public AtomicTime()

immediately activates the instance and schedules updates in the interval given. Interval is 24h.

AtomicTime

public AtomicTime(boolean activateNow)

Interval is 24h.

AtomicTime

public AtomicTime(boolean activateNow,
                  long updateIntervalMillis)
           throws IllegalArgumentException

immediately activates the instance and schedules updates in the interval given.

Parameters:

updateIntervalMillis - must represent more than a minute

Throws:

IllegalArgumentException - if the interval represents less than a minute

AtomicTime

public AtomicTime(boolean activateNow,
                  long updateIntervalMillis,
                  Logger logger)
           throws IllegalArgumentException

Parameters:

activateNow - if true, the instance is immediately activated

updateIntervalMillis - must represent more than a minute

logger - used to log the scheduled delta updates for the atomic clock

Throws:

IllegalArgumentException - if the interval represents less than 5 minutes

Method Detail

isActivated

public boolean isActivated()

getUpdateIntervalMillis

public long getUpdateIntervalMillis()

setUpdateIntervalMillis

public void setUpdateIntervalMillis(long updateIntervalMillis)
                             throws IllegalStateException,
                                    IllegalArgumentException

must be called while the instance is deactivated.

Throws:

IllegalStateException - if this instance is currently activated

IllegalArgumentException - if the interval represents less than 5 minutes

See Also:

isActivated()

activate

public void activate()

activates the embedded timer for automatic updates

deactivate

public void deactivate()

deactivates the embedded timer for automatic updates

finalize

protected void finalize()

Overrides:

finalize in class Object

currentTimeMillis

public long currentTimeMillis()

returns the current time

Specified by:

currentTimeMillis in interface TimeSystem

Returns:

the difference, measured in milliseconds, between the current time and midnight, January 1, 1970 UTC.

getAtomicClock

public AtomicClock getAtomicClock()

returns the clock in use

setLogger

public void setLogger(Logger logger)

may be set to null

getLogger

public Logger getLogger()

may be null

getServerNames

public Set<String> getServerNames()

returned set allows to add/remove server names if required