How do you schedule tasks in Spring Boot 4 with @Scheduled?

// Enable scheduling:
@SpringBootApplication
@EnableScheduling
public class App { ... }

@Service
public class ReportScheduler {

    // Fixed rate: every 60 seconds (interval from start of last execution)
    @Scheduled(fixedRate = 60_000)
    public void generateHourlyMetrics() {
        metricsService.compute();
    }

    // Fixed delay: 30 seconds AFTER last execution completes
    @Scheduled(fixedDelay = 30_000)
    public void cleanExpiredSessions() {
        sessionService.evictExpired();
    }

    // Cron expression: every day at 2:30 AM
    @Scheduled(cron = "0 30 2 * * *")
    public void dailyReport() {
        reportService.generateDailyReport();
    }

    // Cron with zone:
    @Scheduled(cron = "0 0 8 * * MON-FRI", zone = "Europe/London")
    public void morningDigest() {
        digestService.send();
    }

    // Initial delay: wait 5s after startup before first run
    @Scheduled(initialDelay = 5_000, fixedRate = 60_000)
    public void warmUpCache() {
        cacheService.preload();
    }
}

# Cron syntax: second minute hour day-of-month month day-of-week
# "0 */5 * * * *"  = every 5 minutes
# "0 0 * * * *"    = every hour on the hour
# "0 0 9-17 * * MON-FRI" = every hour 9am-5pm Mon-Fri

# Spring Boot 4: multiple TaskDecorator beans supported
# (propagates MDC logging context and security context to scheduled threads)
@Bean
public TaskDecorator mdcTaskDecorator() {
    return runnable -> () -> {
        MDC.put("task", "scheduled");
        try { runnable.run(); } finally { MDC.clear(); }
    };
}