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.
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 ...