Sukejura

cron-like library for kotlin - coroutine based

If you need something executed in set interval, Sukejura is for you!

Sukejura has minute-precision and supports:

• Minutes
• Hours
• DaysOfWeek
• DaysOfMonth
• MonthsOfYear

Sukejura also supports multiple schedules inside the same instance.

basic example

    val sukejura = sukejura {
        schedule {
            // every working day of the week
            daysOfWeek {
                listOf(
                    DaysOfWeek.Mon,
                    DaysOfWeek.Tue,
                    DaysOfWeek.Wed,
                    DaysOfWeek.Thu,
                    DaysOfWeek.Fri
                )
            }
            // at 9am and 5pm
            hours {
                listOf(
                    Hours.H(9),
                    Hours.H(17)
                )
            }
            // every time the minute is 0
            minute { Minutes.M(0) }
            task {
                println("hello there!")
            }
        }
        start()
    }
    sukejura.schedules.first().invocations().take(20).forEach {
        println("triggering at: $it")
    }

// triggering at: 2018-11-05T09:00
// triggering at: 2018-11-05T17:00
// triggering at: 2018-11-06T09:00
// triggering at: 2018-11-06T17:00
// triggering at: 2018-11-07T09:00
// triggering at: 2018-11-07T17:00
// triggering at: 2018-11-08T09:00
// triggering at: 2018-11-08T17:00
// triggering at: 2018-11-09T09:00
// triggering at: 2018-11-09T17:00
// triggering at: 2018-11-12T09:00
// triggering at: 2018-11-12T17:00
// triggering at: 2018-11-13T09:00
// triggering at: 2018-11-13T17:00
// triggering at: 2018-11-14T09:00
// triggering at: 2018-11-14T17:00
// triggering at: 2018-11-15T09:00
// triggering at: 2018-11-15T17:00
// triggering at: 2018-11-16T09:00
// triggering at: 2018-11-16T17:00

For more examples see the examples subproject

How to get Sukejura

Sukejura is published at jcenter.

Gradle

allprojects {
    repositories {
        jcenter()
    }
}
...
dependencies {
    compile 'io.kesselring.sukejura:Sukejura:<version>'
}

Maven

<repositories>
    <repository>
        <id>central</id>
        <name>bintray</name>
        <url>https://jcenter.bintray.com</url>
    </repository>
</repositories>
...
<dependency>
    <groupId>io.kesselring.sukejura</groupId>
    <artifactId>Sukejura</artifactId>
    <version>#version#</version>
</dependency>

Behaviour

default values

Default value for every configuration type is every time, so creating Sukejura without any config will result in a task executed every minute.

Parallelism

Internally, Sukejura uses a single Thread for as dispatcher. If you use multiple schedules, the tasks will be executed effectively sequential. However, if you do non-blocking suspension in your task, you shouldn't have any problems.

Time tracking

Sukejura only keeps track of the last truncated minute the task has been executed at. This means:

• Initial execution won't wait for a full minute (use skipInitialExecution() if you want it to wait)
• If a task execution needs more time than one interval, executions might be skipped (task won't run in parallel)

multiple schedules

Sukejura supports more than one schedule.

about the name

Sukejura or better: Sukejūra / スケジューラ means scheduler in english

Patterns

Every even minute:

minutes { (0..59 step 2).map { Minutes.M(it) } }

Every 5 minutes:

minutes { (0..59 step 5).map { Minutes.M(it) } }

Last Day of February 00:00; only leap years:

monthOfYear { MonthsOfYear.Feb }
dayOfMonth {
    DaysOfMonth.D(29)
}
minute { Minutes.M(0) }
hour { Hours.H(0) }