how to set cron expression dynamically with database values for different jobs in spring 4

Question

I want to configure scheduler in my application where I have to set cron expression with database values dynamically. When application starts, a method should fetch the database values in set them in cron expression for a particular job. Please help me with this. I am all new to quartz scheduler, spring scheduler concepts

Answer 1

You can very well use TaskScheduler class of Spring Scheduling in this case.

Please have a look at the class definition:

https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/scheduling/TaskScheduler.html

scheduler.schedule(runnableTask, new CronTrigger(cron, TimeZone.getTimeZone(timezone)));

You can create a runnable task as follows:

class RunnableTask implements Runnable {
    @Override
    public void run() {
        //
    }
}

While creating a cron trigger, you can load cron expression from database.

Answer 2

You may want to look at this answer. https://stackoverflow.com/a/4499229/82632

Basically you need to autowire TaskScheduler class then programmatically add jobs with it.