Annotation Type Schedule
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@Target(METHOD) @Retention(RUNTIME) @Repeatable(Schedules.class) public @interface Schedule
Schedule a timer for automatic creation with a timeout schedule based on a cron-like time expression. The annotated method is used as the timeout callback method.All elements of this annotation are optional. If none are specified a persistent timer will be created with callbacks occuring every day at midnight in the default time zone associated with the container in which the application is executing.
There are seven elements that constitute a schedule specification which are listed below. In addition, the
timezone
element may be used to specify a non-default time zone in whose context the schedule specification is to be evaluated; thepersistent
element may be used to specify a non-persistent timer, and theinfo
element may be used to specify additional information that may be retrieved when the timer callback occurs.The elements that specify the calendar-based schedule itself are as follows:
- second : one or more seconds within a minute
Allowable values: [0,59]
- minute : one or more minutes within an hour
Allowable values : [0,59]
- hour : one or more hours within a day
Allowable values : [0,23]
- dayOfMonth : one or more days within a month
Allowable values:
- [1,31]
- [-7, -1]
- "Last"
- {"1st", "2nd", "3rd", "4th", "5th", "Last"} {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"}
"Last" means the last day of the month
-x (where x is in the range [-7, -1]) means x day(s) before the last day of the month
"1st","2nd", etc. applied to a day of the week identifies a single occurrence of that day within the month.
- month : one or more months within a year
Allowable values :
- [1,12]
- {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", Dec"}
- dayOfWeek : one or more days within a week
Allowable values :
- [0,7]
- {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"}
"0" and "7" both refer to Sunday
- year : a particular calendar year
Allowable values : a four-digit calendar year
Each element supports values expressed in one of the following forms
- Single Value. This constrains the attribute to only one of its possible values.
Example: second = "10" Example: month = "Sep"
- Wild Card. "*" represents all allowable values for a given attribute.
Example: second = "*" Example: dayOfWeek = "*"
- List. This constrains the attribute to two or more allowable values or ranges, with a comma used as a separator
character within the string. Each item in the list must be a single value or range. List items cannot be lists, wild
cards, or increments. Duplicate values are ignored.
Example: second = "10,20,30" Example: dayOfWeek = "Mon,Wed,Fri" Example: minute = "0-10,30,40"
- Range. This constrains the attribute to an inclusive range of values, with a dash separating both ends of the
range. Each side of the range must be a single attribute value. Members of a range cannot be lists, wild cards,
ranges, or increments. If
x
is larger thany
in a range"x-y"
, the range is equivalent to"x-max, min-y"
, wheremax
is the largest value of the corresponding attribute andmin
is the smallest. The range"x-x"
, where both range values are the same, evaluates to the single valuex
. The day of the week range"0-7"
is equivalent to"*"
.Example: second = "1-10" Example: dayOfWeek = "Fri-Mon" Example: dayOfMonth = "27-3" (Equivalent to "27-Last , 1-3")
- Increments. The forward slash constrains an attribute based on a starting point and an interval, and is used to
specify every
N
seconds, minutes, or hours within the minute, hour, or day, respectively. For the expressionx/y
, the attribute is constrained to everyy
th value within the set of allowable values beginning at timex
. Thex
value is inclusive. The wild card character (*
) can be used in thex
position, and is equivalent to0
. The use of increments is only supported within thesecond
,minute
, andhour
elements. For thesecond
andminute
elements,x
andy
must each be in the range[0,59]
. For thehour
element,x
andy
must each be in the range[0,23]
.Example: minute = "∗/5" (Every five minutes within the hour)
This is equivalent to:minute = "0,5,10,15,20,25,30,35,40,45,50,55"
Example: second = "30/10" (Every 10 seconds within the minute, starting at second 30)
This is equivalent to:second = "30,40,50"
Note that the set of matching increment values stops once the maximum value for that attribute is exceeded. It does not "roll over" past the boundary.
Example : ( minute = "∗/14", hour="1,2")
This is equivalent to:
(minute = "0,14,28,42,56", hour = "1,2")
(Every 14 minutes within the hour, for the hours of 1 and 2 a.m.)
The following additional rules apply to the schedule specification elements:
- If the
dayOfMonth
element has a non-wildcard value and thedayOfWeek
element has a non-wildcard value, then any day matching either thedayOfMonth
value or thedayOfWeek
value will be considered to apply. - Whitespace is ignored, except for string constants and numeric values.
- All string constants (e.g.,
"Sun"
,"Jan"
,"1st"
, etc.) are case insensitive.
Schedule-based timer times are evaluated in the context of the default time zone associated with the container in which the application is executing. A schedule-based timer may optionally override this default and associate itself with a specific time zone. If the schedule-based timer is associated with a specific time zone, all its times are evaluated in the context of that time zone, regardless of the default time zone in which the container is executing.
The timeout callback method to which the
Schedule
annotation is applied must have one of the following signatures, where<METHOD>
designates the method name:void <METHOD>() void <METHOD>(Timer timer)
A timeout callback method can have public, private, protected, or package level access. A timeout callback method must not be declared as final or static. Timeout callback methods must not throw application exceptions.- Since:
- EJB 3.1
- second : one or more seconds within a minute
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Optional Element Summary
Optional Elements Modifier and Type Optional Element Description String
dayOfMonth
Specifies one or more days within a month.String
dayOfWeek
Specifies one or more days within a week.String
hour
Specifies one or more hours within a day.String
info
Specifies an information string that is associated with the timerString
minute
Specifies one or more minutes with an hour.String
month
Specifies one or more months within a year.boolean
persistent
Specifies whether the timer that is created is persistent.String
second
Specifies one or more seconds with in a minute.String
timezone
Specifies the time zone within which the schedule is evaluated.String
year
Specifies one or more years.
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timezone
String timezone
Specifies the time zone within which the schedule is evaluated. Time zones are specified as an ID string. The set of required time zone IDs is defined by the Zone Name(TZ) column of the public domain zoneinfo database.If a timezone is not specified, the schedule is evaluated in the context of the default timezone associated with the contianer in which the application is executing.
- Returns:
- a
String
object.
- Default:
- ""
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