CronTrigger is not triggering at specified time bu

Question

I am using Amazon Push Notifications in my Spring MVC 4 project. I have used CronTrigger to send push notifications to Android app everyday at 8am. I have also used Timezone along with CronTrigger so that users get notifications according to their respective timezones.

Here is my WebConfig.java:

@Configuration
@EnableScheduling
@EnableWebMvc
@ComponentScan(basePackages="com.project")
public class WebConfig implements SchedulingConfigurer 
{    
    protected static final Logger slf4jLogger  =  Logger.getLogger(WebConfig.class.getName());
private static final String cronExpression = "0 8 * * * ?";



/*@Bean
public MobileNotifSchedulerBean schedulerbean()
{
    return new MobileNotifSchedulerBean();
}*/

@Bean
public InternalResourceViewResolver getInternalResourceViewResolver()
{
    InternalResourceViewResolver resolver = new InternalResourceViewResolver();
    resolver.setPrefix("/WEB-INF/jsp/");
    resolver.setSuffix(".jsp");
    resolver.setSuffix(".html");
    resolver.setSuffix(".htm");
    return resolver;
}

@Bean
CronTrigger cronTrigger() 
{
  //The code in FetchUserTimeZones.java fetches all the user timezones which are stored in DynamoDb. Eg timeZone = "Asia/Calcutta";
   String timeZone = null;
    HashSet<String> userTimeZonesfromDB = FetchUserTimeZones.fetchUserTimeZone();
    for (String s : userTimeZonesfromDB) 
    {
        timeZone = s;
        slf4jLogger.info(s);
    }
    return new CronTrigger(cronExpression, TimeZone.getTimeZone(timeZone));
}


@Override
public void configureTasks(ScheduledTaskRegistrar taskRegistrar) 
{

    taskRegistrar.addCronTask(new CronTask(new MobileNotifSchedulerBean(), cronTrigger()));
}

@Bean(destroyMethod="shutdown")
public Executor taskExecutor() 
{
    return Executors.newScheduledThreadPool(1);
  } 
}

Here is my MobileNotifSchedulerBean: This code fetches a random question from DynamoDb and send them in Push Notification for each GCM registrationID with help of the CronTrigger set to time (8am). I have used snsmobilepush.zip from http://docs.aws.amazon.com/sns/latest/dg/mobile-push-gcm.html.

@EnableScheduling
public class MobileNotifSchedulerBean implements Runnable 
{
   protected static final Logger slf4jLogger  = Logger.getLogger(MobileNotifSchedulerBean.class.getName());

public MobileNotifSchedulerBean()
{
     run();
}

public void sendQuestionNotif() 
{
    try 
    {
        HashSet<String> reg_ids = FetchRegistrationIDs.fetchItems();
        for (String s : reg_ids) 
        {
            String REGISTRATION_IDs = s;
            slf4jLogger.info(s);                
            MobileSNSPushNotification.sendNotification(REGISTRATION_IDs);
        }
    } 
    catch (IOException e) 
    {
        //e.printStackTrace();
        slf4jLogger.error(e);
        slf4jLogger.error(e.getMessage());
        slf4jLogger.error(e.getStackTrace());
    }
}


@Override
public void run() 
{
    sendQuestionNotif();
}
}

Please help me where I have went wrong. Only problem is push notifications are going in wrong times and also multiple number of notifications instead of going only 1 push notification per user, per day(8am). TIA.

Update: There was a correction in Cron Expression. I corrected it.

private static final String cronExpression = "0 0 8 * * ?";  // For everyday 8 am. 

But still problem hasn't fixed

Answer 1

You should create a separate schedule for each user

// spring bean 
class Task implements Runnable {

    public Task(TaskScheduler scheduler, String cron) {
        HashSet<String> userTimeZonesfromDB = FetchUserTimeZones.fetchUserTimeZone();
        for (String tz : userTimeZonesfromDB) {
            scheduler.schedule(this, new CronTrigger(cron, TimeZone.getTimeZone(tz)));
        }
    }

    @Override
    public void run() {
        // notify
    }
}