Schedule a task with Cron which allows dynamic update

Question

I use sprint boot 1.3, spring 4.2

In this class

@Service
public class PaymentServiceImpl implements PaymentService {
    ....
    @Transactional
    @Ove         


        

Answer 1

Looking at the question seems like you want to update the scheduler, without restart.

The code you have shared only ensures the config is picked from DB, but it will not refresh without application restart.

The following code will use the default scheduler available in the spring context and dynamically compute the next execution time based on the available cron setting in the DB:

Here is the sample code:

import java.util.Date;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.TriggerContext;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.SchedulingConfigurer;
import org.springframework.scheduling.config.ScheduledTaskRegistrar;
import org.springframework.scheduling.support.CronTrigger;

@SpringBootApplication
@EnableScheduling
public class Perses implements SchedulingConfigurer {
    private static final Logger log = LoggerFactory.getLogger(Perses.class);

    @Autowired
    private DefaultConfigService defaultConfigService;

    @Autowired
    private PaymentService paymentService;

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

    private String cronConfig() {
        String cronTabExpression = "*/5 * * * * *";
        if (defaultConfigDto != null && !defaultConfigDto.getFieldValue().isEmpty()) {
            cronTabExpression = "0 0 4 * * ?";
        }
        return cronTabExpression;
    }

    @Override
    public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
        taskRegistrar.addTriggerTask(new Runnable() {
            @Override
            public void run() {
                paymentService.processPayment();
            }
        }, new Trigger() {
            @Override
            public Date nextExecutionTime(TriggerContext triggerContext) {
                String cron = cronConfig();
                log.info(cron);
                CronTrigger trigger = new CronTrigger(cron);
                Date nextExec = trigger.nextExecutionTime(triggerContext);
                return nextExec;
            }
        });
    }
}