go-quartz

README

go-quartz

A minimalistic and zero-dependency scheduling library for Go.

About

Inspired by the Quartz Java scheduler.

Library building blocks

Scheduler interface

type Scheduler interface {
	// Start starts the scheduler.
	Start()
	// IsStarted determines whether the scheduler has been started.
	IsStarted() bool
	// ScheduleJob schedules a job using a specified trigger.
	ScheduleJob(job Job, trigger Trigger) error
	// GetJobKeys returns the keys of all of the scheduled jobs.
	GetJobKeys() []int
	// GetScheduledJob returns the scheduled job with the specified key.
	GetScheduledJob(key int) (*ScheduledJob, error)
	// DeleteJob removes the job with the specified key from the Scheduler's execution queue.
	DeleteJob(key int) error
	// Clear removes all of the scheduled jobs.
	Clear()
	// Stop shutdowns the scheduler.
	Stop()
}

Implemented Schedulers

• StdScheduler

Trigger interface

type Trigger interface {
	// NextFireTime returns the next time at which the Trigger is scheduled to fire.
	NextFireTime(prev int64) (int64, error)
	// Description returns the description of the Trigger.
	Description() string
}

Implemented Triggers

• CronTrigger
• SimpleTrigger
• RunOnceTrigger

Job interface. Any type that implements it can be scheduled.

type Job interface {
	// Execute is called by a Scheduler when the Trigger associated with this job fires.
	Execute()
	// Description returns the description of the Job.
	Description() string
	// Key returns the unique key for the Job.
	Key() int
}

Implemented Jobs

• ShellJob
• CurlJob

Cron expression format

Field Name	Mandatory	Allowed Values	Allowed Special Characters
Seconds	YES	0-59	, - * /
Minutes	YES	0-59	, - * /
Hours	YES	0-23	, - * /
Day of month	YES	1-31	, - * ? /
Month	YES	1-12 or JAN-DEC	, - * /
Day of week	YES	1-7 or SUN-SAT	, - * ? /
Year	NO	empty	*

Examples

sched := quartz.NewStdScheduler()
sched.Start()
cronTrigger, _ := quartz.NewCronTrigger("1/5 * * * * *")
shellJob := quartz.NewShellJob("ls -la")
curlJob, _ := quartz.NewCurlJob(http.MethodGet, "http://worldclockapi.com/api/json/est/now", "", nil)
sched.ScheduleJob(shellJob, cronTrigger)
sched.ScheduleJob(curlJob, quartz.NewSimpleTrigger(time.Second*7))
sched.Stop()

More code samples can be found in the examples directory.

License

Licensed under the MIT License.