[ Schedule task for specific time from spring 4 web mvc ]

I am building a Spring 4 Rest API for a trade automation site.

An http request will contain some info along with a date-time. After inserting these info into database (using hibernate), I need to dynamically create a new cron job which will access these db info and do something. The cron job must be executed at the time specified above.

So there wont be a fixed cron expression, also the cron task must access my DAO layer annoted with @Repository. Even after referring a lot of post in stack and other blog, which tells about @Scheduled, Spring-Quartz integration, I couldn't find out a solution for my specific need.

Java/Annotation configuration is preferred.

Please help. Thanks

Answer 1

I think you may use something like this: https://ha-jdbc.github.io/apidocs/net/sf/hajdbc/util/concurrent/cron/CronThreadPoolExecutor.html

Answer 2

You can use Trigger and TaskScheduler interfaces. Example below. To cancel job in the future it will be needed to store ScheduledFuture instance.

@Configuration
public class AppConfiguration {

    @Bean
    public ThreadPoolTaskScheduler taskScheduler() {
        return new ThreadPoolTaskScheduler();
    }
}

@Controller
public class TriggerService {

    @Autowired
    private TaskScheduler scheduler;

    @Autowired
    private DAOService db;

    private ScheduledFuture job;        

    @GetMapping("/task1")
    @ResponseBody
    public void triggerMyTask(@RequestParam String cronExpression) {

        Runnable runnable = new Runnable() {            
            @Override
            public void run() {
                log.info(new Date());
                /**
                 * here You can do what You want with db
                 * using some DAOService
                 */         
                db.count();
            }
        };

        /**
         * cancel current task if You need
         */
        if(job != null) {
           job.cancel(true);
        }

        CronTrigger trigger = new CronTrigger(cronExpression);
        job = scheduler.schedule(runnable, trigger);
    }
}

You can pass cron expression for example like that:

http://localhost:8080/task1?cronExpression=0/5%20*%20*%20*%20*%20*