spring-scheduling

Spring Scheduling & Async

Full Reference: See async.md for async configuration, multiple executors, and CompletableFuture patterns. Full Reference: See distributed.md for ShedLock, error handling, dynamic scheduling, and testing.

Quick Start

@SpringBootApplication
@EnableScheduling
@EnableAsync
public class Application {}

@Service
@Slf4j
public class ScheduledTasks {

    @Scheduled(fixedRate = 60000)  // Every minute
    public void runEveryMinute() {
        log.info("Task executed at {}", LocalDateTime.now());
    }

    @Async
    public CompletableFuture<String> asyncOperation() {
        return CompletableFuture.completedFuture("Done");
    }
}

@Scheduled

Fixed Rate vs Fixed Delay

@Service
public class ScheduledTasks {

    // Fixed Rate: runs every 5s from start of previous
    @Scheduled(fixedRate = 5000)
    public void fixedRateTask() { }

    // Fixed Delay: runs 5s after previous completes
    @Scheduled(fixedDelay = 5000)
    public void fixedDelayTask() { }

    // Initial delay before first run
    @Scheduled(fixedRate = 5000, initialDelay = 10000)
    public void delayedStart() { }

    // Configurable via properties
    @Scheduled(fixedRateString = "${task.rate:5000}")
    public void configurableTask() { }

    // With TimeUnit
    @Scheduled(fixedRate = 1, timeUnit = TimeUnit.MINUTES)
    public void everyMinute() { }
}

Cron Expressions

@Service
public class CronTasks {

    // Daily at 2:00 AM
    @Scheduled(cron = "0 0 2 * * *")
    public void dailyAt2AM() { }

    // Every Monday at 9:00 AM
    @Scheduled(cron = "0 0 9 * * MON")
    public void everyMondayAt9AM() { }

    // Every 15 minutes during business hours (9-18)
    @Scheduled(cron = "0 */15 9-18 * * MON-FRI")
    public void businessHoursTask() { }

    // With timezone
    @Scheduled(cron = "0 0 9 * * *", zone = "Europe/Rome")
    public void dailyAt9AMRome() { }

    // Disable with "-"
    @Scheduled(cron = "${task.cron:-}")
    public void optionalTask() { }
}