Spring cron expression for every after 30 minutes

According to the Quartz-Scheduler Tutorial It should be value="0 0/30 * * * ?"

The field order of the cronExpression is

Seconds Minutes Hours Day-of-Month Month Day-of-Week Year (optional field)

Ensure you have at least 6 parameters or you will get an error (year is optional).

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Graphically, the cron syntax for Quarz is (source):

+-------------------- second (0 - 59)
|  +----------------- minute (0 - 59)
|  |  +-------------- hour (0 - 23)
|  |  |  +----------- day of month (1 - 31)
|  |  |  |  +-------- month (1 - 12)
|  |  |  |  |  +----- day of week (0 - 6) (Sunday=0 or 7)
|  |  |  |  |  |  +-- year [optional]
|  |  |  |  |  |  |
*  *  *  *  *  *  * command to be executed 

So if you want to run a command every 30 minutes you can say either of these:

0 0/30 * * * * ?
0 0,30 * * * * ?

You can check crontab expressions using either of these:

crontab.guru — (disclaimer: I am not related to that page at all, only that I find it very useful). This page uses UNIX style of cron that does not have seconds in it, while Spring does as the first field.

Cron Expression Generator & Explainer - Quartz — cron formatter, allowing seconds also.

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<property name="cronExpression" value="0 0/30 * * * ?" />

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In my Java Spring web application, this is what worked for me:

cron="0 0/30 * * * ?"

This will trigger on for example 10:00 AM, then 10:30 AM etc.

Here is a full configuration file:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:beans="http://www.springframework.org/schema/beans"
       xmlns:task="http://www.springframework.org/schema/task"
       xsi:schemaLocation="
    http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/task 
    http://www.springframework.org/schema/task/spring-task.xsd">

    <beans profile="cron">
        <bean id="executorService" class="java.util.concurrent.Executors" factory-method="newFixedThreadPool">
            <beans:constructor-arg value="5" />
        </bean>

        <task:executor id="threadPoolTaskExecutor" pool-size="5" />
        <task:annotation-driven executor="executorService" />

        <beans:bean id="expireCronJob" class="com.cron.ExpireCron"/>

        <task:scheduler id="serverScheduler" pool-size="5"/>
        <task:scheduled-tasks scheduler="serverScheduler">
            <!-- every thirty minutes -->
            <task:scheduled ref="expireCronJob" method="runTask" cron="0 0/30 * * * ?"/>
        </task:scheduled-tasks>

    </beans>

</beans>

I dont know why but this is working on my local develop and production, but other changes if I made I have to be careful, because it may work local and on develop, but not on production.

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If someone is using @Sceduled this might work for you.

@Scheduled(cron = "${name-of-the-cron:0 0/30 * * * ?}")

This worked for me.

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