What is best way to schedule task in spring boot application

Question

I am current developing an application based on Spring-Boot.

I know that annotation like @Scheduled can schedule tasks. Since users in my application wanna send mails at different time and send only once.

I have already read the post Spring scheduling task - run only once, but it is weird always "new" an localExecutor in a Spring based application.

In that way , once a user schedule sending an email, I have to "new" an localExecutor for his task.

So , are there any better ways?

Answer 1

The simplest way to schedule tasks in Spring is to create method annotated by @Scheduled in spring managed bean. It also required @EnableScheduling in any @Configuration classes.

Spring tutorial

Answer 2

You can use crontab inside @Scheduled

 private AtomicInteger counter = new AtomicInteger(0);

@Scheduled(cron = "*/2 * * * * *")
public void cronJob() {
    int jobId = counter.incrementAndGet();
    System.out.println("Job " + new Date() + ", jobId: " + jobId);
}

Answer 3

you should use quartz-scheduler and send mails at different time and send only once.- put this as a business logic in your code. Please see for spring boot -quartz integration https://github.com/davidkiss/spring-boot-quartz-demo

Answer 4

Spring @Scheduled annotation will execute multiple times if you have more than one instance of your app where you have @Scheduled annotation.

If you are using PCF, you can use PCF scheduler https://docs.pivotal.io/scheduler/1-2/using-jobs.html to avoid this issue. Using Tasks can solve this issue.