org.springframework.scheduling.annotation

Annotation Type Scheduled

@Target(value={METHOD,ANNOTATION_TYPE})
 @Retention(value=RUNTIME)
 @Documented
 @Repeatable(value=Schedules.class)
public @interface Scheduled

Annotation that marks a method to be scheduled. Exactly one of the cron(), fixedDelay(), or fixedRate() attributes must be specified.

The annotated method must expect no arguments. It will typically have a void return type; if not, the returned value will be ignored when called through the scheduler.

Processing of @Scheduled annotations is performed by registering a ScheduledAnnotationBeanPostProcessor. This can be done manually or, more conveniently, through the <task:annotation-driven/> element or @EnableScheduling annotation.

This annotation may be used as a meta-annotation to create custom composed annotations with attribute overrides.

Since:

3.0

Author:

Mark Fisher, Juergen Hoeller, Dave Syer, Chris Beams

See Also:

EnableScheduling, ScheduledAnnotationBeanPostProcessor, Schedules

Field Summary

Fields

Modifier and Type	Fields and Description
static String	CRON_DISABLED A special cron expression value that indicates a disabled trigger: "-".

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
String	cron A cron-like expression, extending the usual UN*X definition to include triggers on the second, minute, hour, day of month, month, and day of week.
long	fixedDelay Execute the annotated method with a fixed period in milliseconds between the end of the last invocation and the start of the next.
String	fixedDelayString Execute the annotated method with a fixed period in milliseconds between the end of the last invocation and the start of the next.
long	fixedRate Execute the annotated method with a fixed period in milliseconds between invocations.
String	fixedRateString Execute the annotated method with a fixed period in milliseconds between invocations.
long	initialDelay Number of milliseconds to delay before the first execution of a fixedRate() or fixedDelay() task.
String	initialDelayString Number of milliseconds to delay before the first execution of a fixedRate() or fixedDelay() task.
String	zone A time zone for which the cron expression will be resolved.

Field Detail

CRON_DISABLED

public static final String CRON_DISABLED

A special cron expression value that indicates a disabled trigger: "-".

This is primarily meant for use with ${...} placeholders, allowing for external disabling of corresponding scheduled methods.

Since:

5.1

See Also:

ScheduledTaskRegistrar.CRON_DISABLED

Element Detail

cron

public abstract String cron

A cron-like expression, extending the usual UN*X definition to include triggers on the second, minute, hour, day of month, month, and day of week.

For example, "0 * * * * MON-FRI" means once per minute on weekdays (at the top of the minute - the 0th second).

The fields read from left to right are interpreted as follows.

• second
• minute
• hour
• day of month
• month
• day of week

The special value "-" indicates a disabled cron trigger, primarily meant for externally specified values resolved by a ${...} placeholder.

Returns:

an expression that can be parsed to a cron schedule

See Also:

CronExpression.parse(String)

Default:

""

zone

public abstract String zone

A time zone for which the cron expression will be resolved. By default, this attribute is the empty String (i.e. the server's local time zone will be used).

Returns:

a zone id accepted by TimeZone.getTimeZone(String), or an empty String to indicate the server's default time zone

Since:

4.0

See Also:

CronTrigger(String, java.util.TimeZone), TimeZone

Default:

""

fixedDelay

public abstract long fixedDelay

Execute the annotated method with a fixed period in milliseconds between the end of the last invocation and the start of the next.

Returns:

the delay in milliseconds

Default:

-1L

fixedDelayString

public abstract String fixedDelayString

Execute the annotated method with a fixed period in milliseconds between the end of the last invocation and the start of the next.

Returns:

the delay in milliseconds as a String value, e.g. a placeholder or a java.time.Duration compliant value

Since:

3.2.2

Default:

""

fixedRate

public abstract long fixedRate

Execute the annotated method with a fixed period in milliseconds between invocations.

Returns:

the period in milliseconds

Default:

-1L

fixedRateString

public abstract String fixedRateString

Execute the annotated method with a fixed period in milliseconds between invocations.

Returns:

the period in milliseconds as a String value, e.g. a placeholder or a java.time.Duration compliant value

Since:

3.2.2

Default:

""

initialDelay

public abstract long initialDelay

Number of milliseconds to delay before the first execution of a fixedRate() or fixedDelay() task.

Returns:

the initial delay in milliseconds

Since:

3.2

Default:

-1L

initialDelayString

public abstract String initialDelayString

Number of milliseconds to delay before the first execution of a fixedRate() or fixedDelay() task.

Returns:

the initial delay in milliseconds as a String value, e.g. a placeholder or a java.time.Duration compliant value

Since:

3.2.2

Default:

""