[SOLVED] Spring boot: @Scheduler that updates cron espression without restarting

Issue

I Need to schedule a task on Spring Boot that reads a cron espression from the database. I did this using the @Scheduled annotation and reading a property inside a database, but my client is asking to be able to update the cron expression in the database and having it affect the scheduled without restarting the application. I know this isnt possible with the @Scheduled annotation, but would It be possible to schedule another task that extracts the cron expression every hour, and then feed the updated expression to the actual scheduled that executes the task? Basically updating the variable that Is Fed to the second scheduled. If this isnt possible, do you know any alternative ways to achieve this without using the @Scheduled annotation? Thank you.

Solution

Solved this using SchedulingConfigurer, here's a sample:

@Configuration
@EnableScheduling
public class BatchConfig implements SchedulingConfigurer {

  

    @Override
    public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
        taskRegistrar.addTriggerTask(new Runnable() {
            @Override
            public void run() {


                //run your code here
            }
        }, new Trigger() {
            @Override
            public Date nextExecutionTime(TriggerContext triggerContext) {
             //extract cron from database

                

                CronTrigger trigger = new CronTrigger(new CronTrigger(//insert cron that you got from database));
                return trigger.nextExecutionTime(triggerContext);
            }
        });
    }
}

Answered By - R.S.

Answer Checked By - Willingham (WPSolving Volunteer)