@javax.ejb.Schedule: Difference between revisions
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=Usage Rules= | |||
The annotation must be applied to the method implementation, in the bean class. If applied to the method declaration in the interface, it will be ignored. | |||
The methods must have the following signatures; | |||
void ''method_name''() | |||
void ''method_name''(Timer timer) | |||
A timeout callback method can have public, private, protected, or package level access. It must not be declared as final or static. It must not throw application exceptions. | |||
An EJB can have any number of automatically created timers. | |||
=Configuration= | =Configuration= | ||
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* year | * year | ||
<blockquote style="background-color: Gold; border: solid thin Goldenrod;"> | |||
:<br>If you intend to test a time firing every other few seconds, make sure to specify hour="*" and minute="*". If they are not specified, the default values are 0 and 0, respectively, which means your timer will start firing at midnight next day, for maximum a minute.<br><br> | |||
</blockquote> | |||
The following example fires a timer every 20 seconds, continuously: | The following example fires a timer every 20 seconds, continuously: | ||
Latest revision as of 17:05, 25 September 2017
External
Internal
Overview
Used by EJB to designate timeout callback methods that will be invoked by automatically-created timers.
Example:
@Schedule(hour="3", dayOfMonth="1", info="something")
public void toBeExecutedAt3AMOnTheFirstDayOfTheMonth() {
...
}
Usage Rules
The annotation must be applied to the method implementation, in the bean class. If applied to the method declaration in the interface, it will be ignored.
The methods must have the following signatures;
void method_name() void method_name(Timer timer)
A timeout callback method can have public, private, protected, or package level access. It must not be declared as final or static. It must not throw application exceptions.
An EJB can have any number of automatically created timers.
Configuration
The annotation is configured using a cron-like time expression, using the following attributes:
- second (if not specified, default is 0)
- minute (if not specified, default is 0)
- hour (if not specified, default is 0)
- dayOfMonth
- month
- dayOfWeek
- year
If you intend to test a time firing every other few seconds, make sure to specify hour="*" and minute="*". If they are not specified, the default values are 0 and 0, respectively, which means your timer will start firing at midnight next day, for maximum a minute.
The following example fires a timer every 20 seconds, continuously:
@Schedule(hour="*", minute="*", second = "0/20")
public void fireEvery20SecsContinously() {
...
}