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/> XML 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, Victor Brown, Sam Brannen

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 between the end of the last invocation and the start of the next.
String	fixedDelayString Execute the annotated method with a fixed period between the end of the last invocation and the start of the next.
long	fixedRate Execute the annotated method with a fixed period between invocations.
String	fixedRateString Execute the annotated method with a fixed period between invocations.
long	initialDelay Number of units of time to delay before the first execution of a fixedRate() or fixedDelay() task.
String	initialDelayString Number of units of time to delay before the first execution of a fixedRate() or fixedDelay() task.
TimeUnit	timeUnit The TimeUnit to use for fixedDelay(), fixedDelayString(), fixedRate(), fixedRateString(), initialDelay(), and initialDelayString().
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 between the end of the last invocation and the start of the next.

The time unit is milliseconds by default but can be overridden via timeUnit().

Returns:

the delay

Default:

-1L

fixedDelayString

public abstract String fixedDelayString

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

The time unit is milliseconds by default but can be overridden via timeUnit().

This attribute variant supports Spring-style "${...}" placeholders as well as SpEL expressions.

Returns:

the delay as a String value — for example, a placeholder or a java.time.Duration compliant value

Since:

3.2.2

See Also:

fixedDelay()

Default:

""

fixedRate

public abstract long fixedRate

Execute the annotated method with a fixed period between invocations.

The time unit is milliseconds by default but can be overridden via timeUnit().

Returns:

the period

Default:

-1L

fixedRateString

public abstract String fixedRateString

Execute the annotated method with a fixed period between invocations.

The time unit is milliseconds by default but can be overridden via timeUnit().

This attribute variant supports Spring-style "${...}" placeholders as well as SpEL expressions.

Returns:

the period as a String value — for example, a placeholder or a java.time.Duration compliant value

Since:

3.2.2

See Also:

fixedRate()

Default:

""

initialDelay

public abstract long initialDelay

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

The time unit is milliseconds by default but can be overridden via timeUnit().

Returns:

the initial

Since:

3.2

Default:

-1L

initialDelayString

public abstract String initialDelayString

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

The time unit is milliseconds by default but can be overridden via timeUnit().

This attribute variant supports Spring-style "${...}" placeholders as well as SpEL expressions.

Returns:

the initial delay as a String value — for example, a placeholder or a java.time.Duration compliant value

Since:

3.2.2

See Also:

initialDelay()

Default:

""

timeUnit

public abstract TimeUnit timeUnit

The TimeUnit to use for fixedDelay(), fixedDelayString(), fixedRate(), fixedRateString(), initialDelay(), and initialDelayString().

Defaults to TimeUnit.MILLISECONDS.

This attribute is ignored for cron expressions and for Duration values supplied via fixedDelayString(), fixedRateString(), or initialDelayString().

Returns:

the TimeUnit to use

Since:

5.3.10

Default:

java.util.concurrent.TimeUnit.MILLISECONDS