Scheduled (Spring Framework 5.3.30 API)

```
@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 can be used as a repeatable annotation. If several scheduled declarations are found on the same method, each of them will be processed independently, with a separate trigger firing for each of them. As a consequence, such co-located schedules may overlap and execute multiple times in parallel or in immediate succession.
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: "-".

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

Annotation Type Scheduled

Field Summary

Optional Element Summary

Field Detail

CRON_DISABLED

Element Detail

cron

zone

fixedDelay

fixedDelayString

fixedRate

fixedRateString

initialDelay

initialDelayString

timeUnit