org.oddjob.schedules
Class ConstrainedSchedule

java.lang.Object
  org.oddjob.schedules.AbstractSchedule
      org.oddjob.schedules.ConstrainedSchedule

All Implemented Interfaces:

Serializable, RefineableSchedule, Schedule

Direct Known Subclasses:

DailySchedule, MonthlySchedule, WeeklySchedule, YearlySchedule

public abstract class ConstrainedSchedule
extends AbstractSchedule

A base class for a Schedule which has a from and a to date.

See Also:

Serialized Form

Author:

Rob Gordon

Constructor Summary

ConstrainedSchedule()

Method Summary

protected abstract Calendar	fromCalendar(Date referenceDate, TimeZone timeZone) Provide a Calendar for the start of the constraint.
protected abstract CalendarUnit	intervalBetween() Sub classes must provide a unit which is what must be added to move the schedule on.
protected Interval	lastInterval(ScheduleContext context) Calculate the last interval.
ScheduleResult	nextDue(ScheduleContext context) For a given date a schedule will provide the interval this schedule should next be scheduled in.
protected Interval	nextInterval(ScheduleContext context) Calculate the next interval, without children.
protected Calendar	shiftFromCalendar(Calendar calendar, int intervals) Shift the from Calendar by an interval.
protected Calendar	shiftToCalendar(Calendar calendar, int intervals) Shift the to Calendar by an interval.
protected abstract Calendar	toCalendar(Date referenceDate, TimeZone timeZone) Provide a Calendar for the end of the constraint.
abstract String	toString() Force sub classes to override toString.

Methods inherited from class org.oddjob.schedules.AbstractSchedule

getRefinement, setRefinement

Methods inherited from class java.lang.Object

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

Constructor Detail

ConstrainedSchedule

public ConstrainedSchedule()

Method Detail

fromCalendar

protected abstract Calendar fromCalendar(Date referenceDate,
                                         TimeZone timeZone)

Provide a Calendar for the start of the constraint.

Parameters:

referenceDate - The date/time now.

timeZone - The time zone.

Returns:

A calendar for the from time.

toCalendar

protected abstract Calendar toCalendar(Date referenceDate,
                                       TimeZone timeZone)

Provide a Calendar for the end of the constraint.

Parameters:

referenceDate - The date/time now.

timeZone - The time zone.

Returns:

A calendar for the end time.

intervalBetween

protected abstract CalendarUnit intervalBetween()

Sub classes must provide a unit which is what must be added to move the schedule on. I.e. the equivalent of a day, week, month etc.

Returns:

nextInterval

protected final Interval nextInterval(ScheduleContext context)

Calculate the next interval, without children.

Parameters:

context -

Returns:

lastInterval

protected final Interval lastInterval(ScheduleContext context)

Calculate the last interval.

Parameters:

context -

Returns:

shiftFromCalendar

protected Calendar shiftFromCalendar(Calendar calendar,
                                     int intervals)

Shift the from Calendar by an interval. The subclass fromCalendar is used to re-adjust the shifted calendar. This is needed in at least these situations:

• A yearly schedule for the month of February that returned a toDate in the year before a leap year of the 28th would shift to the 28th as the last day of February in the leap year without re-adjustment.
• A last day of the month schedule that returned 28th in February would shift to the 28th of March without re-adjustment.

Parameters:

calendar -

interval. -

Returns:

shiftToCalendar

protected Calendar shiftToCalendar(Calendar calendar,
                                   int intervals)

Shift the to Calendar by an interval. The subclass toCalendar is used to re-adjust the shifted calendar for the reasons given in shiftFromCalendar(Calendar, int)

Parameters:

calendar -

intervals -

Returns:

nextDue

public ScheduleResult nextDue(ScheduleContext context)

Description copied from interface: Schedule

For a given date a schedule will provide the interval this schedule should next be scheduled in.

If the schedule is never due again for the given date, null is returned.

Returns:

The next due interval for the schedule.

toString

public abstract String toString()

Force sub classes to override toString.

Overrides:

toString in class Object

Returns:

A description of the schedule.