Spring Boot Tutorial (28) Scheduling Tasks

build project

Create a Springboot project, add @EnableScheduling to its program entry, and enable scheduling tasks.

@SpringBootApplication
@EnableScheduling
public class SpringbootSchedulingTasksApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringbootSchedulingTasksApplication.class, args);
    }
}

Create a scheduled task

Create a timed task that prints the current time on the console every 5s.

@Component
public class ScheduledTasks {

    private static final Logger log = LoggerFactory.getLogger(ScheduledTasks.class);

    private static final SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");

    @Scheduled(fixedRate = 5000)
    public void reportCurrentTime() {
        log.info("The time is now {}", dateFormat.format(new Date()));
    }
}

By adding the @Scheduled annotation to the method, it is indicated that the method is a scheduled task.

• @Scheduled(fixedRate = 5000) : Execute again 5 seconds after the last execution time point
• @Scheduled(fixedDelay = 5000) : Execute again 5 seconds after the last execution time point
• @Scheduled(initialDelay=1000, fixedRate=5000) : Execute after the first delay of 1 second, and then execute it every 5 seconds according to the rules of fixedRate
• @Scheduled(cron=" /5 ") : Define rules through cron expressions, what is a cro expression, and search the engine by yourself.

test

Start the springboot project, and the console prints the current time within 5s.

2017-04-29 17:39:37.672 INFO 677 — [pool-1-thread-1] com.forezp.task.ScheduledTasks : The time is now 17:39:37
2017-04-29 17:39:42.671 INFO 677 — [pool-1-thread-1] com.forezp.task.ScheduledTasks : The time is now 17:39:42
2017-04-29 17:39:47.672 INFO 677 — [pool-1-thread-1] com.forezp.task.ScheduledTasks : The time is now 17:39:47
2017-04-29 17:39:52.675 INFO 677 — [pool-1-thread-1] com.forezp.task.ScheduledTasks : The time is now 17:39:52

It only takes 2 steps to create a scheduled task in springboot:

• 1. Add the @EnableScheduling annotation to the entry of the program.
• 2. Add the @Scheduled annotation to the timing method.

source code