Understanding calendar-based scheduling
Calendar-based scheduling is used with the @Schedule annotation and with the ScheduleExpression
class. It provides an alternative approach for specifying the time when a callback should be made. The calendar-based timer expressions are similar to those used by the UNIX Cron facility.
Using a calendar expression we can express one of several types of events:
- A single event in time
- A repeating set of times
- A time interval
This approach provides a more powerful technique for expressing a point in time.
Getting ready
A calendar expression can be expressed using the @Schedule annotation or using a ScheduleExpression
object. These two approaches are closely related. In fact, the Timer
class has an isCalendarTimer
and ...
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