1. Scheduling Basics
1.1. Scheduling Jobs
To create a new job, run the grails create-job command and enter the name of the job. Grails will create a new job and place it in the grails-app/jobs directory:
class MyJob {
static group = 'MyGroup'
static description = 'Example job with Simple Trigger'
static triggers = {
simple(
name: 'mySimpleTrigger',
startDelay: 60000,
repeatInterval: 1000
)
}
void execute() {
println 'Job run!'
}
}The above example will wait for 1 minute and after that will call the execute() method every second. The repeatInterval and startDelay properties are specified in milliseconds and must have Integer or Long type. If these properties are not specified, default values are applied (1 minute for repeatInterval property and 30 seconds for startDelay property). Jobs can optionally be placed in different groups.
The trigger name property must be unique across all triggers in the application.
By default, jobs will not be executed when running under the test environment.
1.1.1. Scheduling a Cron Job
Jobs can be scheduled using a cron expression. For those unfamiliar with cron, this means being able to create a firing schedule such as "At 8:00am every Monday through Friday" or "At 1:30am every last Friday of the month". (See the API docs for the CronTrigger class in Quartz for more info on cron expressions).
class MyJob {
static group = 'MyGroup'
static description = 'Example job with Cron Trigger'
static triggers = {
cron(
name: 'myTrigger',
cronExpression: '0 0 6 * * ?'
)
}
void execute() {
println 'Job run!'
}
}The fields in the cronExpression are: (summarizing the Quartz CronTrigger Tutorial)
cronExpression: "s m h D M W Y"
| | | | | | - Year <<optional>>
| | | | | - Day of Week, 1-7 or SUN-SAT, ?
| | | | - Month, 1-12 or JAN-DEC
| | | - Day of Month, 1-31, ?
| | - Hour, 0-23
| - Minute, 0-59
- Second, 0-59
|