Load Cron syntax from database in spring boot application

Question

This is my Scheduled task class

@Component
public class ScheduledTask {

    private static final Logger LOGGER = LoggerFactory.getLogger(ScheduledTask.class);

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

    @Scheduled(cron = "${scheduling.job.cron}")
    public void reportCurrentTime() {
        LOGGER.info("The time is now {}", dateFormat.format(new Date()));
    }
}

Currently, I am loading cronjob syntax from application.properties file. But I want to load cron syntax from SQL database at the start of Spring boot application. Here is my database script which is having cronjob syntax

CREATE TABLE tbl_configuration_details 
(
config_id int NOT NULL, 
schedule_time int NOT NULL,
schedule_time_format nvarchar(10) NOT NULL,
data_ttl int NOT NULL,
data_ttl_format nvarchar(10) NOT NULL,
cron_job_syntax nvarchar(255) NOT NULL,
created_timestamp datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
created_by int NOT NULL,
modified_timestamp datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
modified_by int NOT NULL,
PRIMARY KEY (config_id)
);

Answer 1

Step 1: Create bean to fetch cron syntax from databse

@Bean
public String getCronSyntax() {
    AppConfiguration appConfiguration = configurationService.getConfiguration();
    String cronSyntax = appConfiguration.getCronJobSyntax();
    LOGGER.info("cronsyntax: " + cronSyntax);
    return cronSyntax;
}

Step 2: Use # to get bean value form cron syntax in Schedule annotation

@Scheduled(cron = "#{getCronSyntax}")
private void cronSchedule() {
     LOGGER.info("The time is now {}", dateFormat.format(new Date()));
}