SpringBoot定时任务怎么避免任务重复执行？分布式解决方案大全

@SpringBootApplication
@EnableScheduling
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

@Scheduled(fixedDelay = 5000) // 5秒
public void reportCurrentTime() {
    log.info("Fixed delay task - {}", LocalDateTime.now());
}

@Scheduled(fixedRate = 3000)
public void pollData() {
    // 注意：若任务执行时间 > 3秒，会并发执行！
}

@Scheduled(cron = "0 0 2 * * ?") // 每天凌晨2点
public void generateDailyReport() {
    // 生成日报
}

@Scheduled(cron = "${task.report.cron:0 0 3 * * ?}")
public void configurableReport() {
    // 支持配置化
}

// org.springframework.scheduling.config.ScheduledTaskRegistrar
private TaskScheduler taskScheduler = new ThreadPoolTaskScheduler();

@Configuration
@EnableScheduling
public class SchedulingConfig implements SchedulingConfigurer {

    @Override
    public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
        taskRegistrar.setScheduler(taskExecutor());
    }

    @Bean(destroyMethod = "shutdown")
    public Executor taskExecutor() {
        ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler();
        scheduler.setPoolSize(5); // 并发执行上限
        scheduler.setThreadNamePrefix("scheduled-task-");
        scheduler.setAwaitTerminationSeconds(60);
        scheduler.setWaitForTasksToCompleteOnShutdown(true);
        return scheduler;
    }
}

@Component
@ConditionalOnProperty(name = "task.daily-report.enabled", havingValue = "true", matchIfMissing = true)
public class DailyReportTask {
    @Scheduled(cron = "0 0 2 * * ?")
    public void run() { /* ... */ }
}

@Scheduled(fixedRate = 60000)
public void monitorCacheRefresh() {
    Timer.Sample sample = Timer.start(meterRegistry);
    try {
        cacheService.refresh();
        log.info("Cache refreshed successfully");
    } catch (Exception e) {
        log.error("Cache refresh failed", e);
    } finally {
        sample.stop(Timer.builder("task.cache.refresh.duration")
                .tag("result", "success")
                .register(meterRegistry));
    }
}

@Scheduled(fixedRate = 30000)
public void distributedTask() {
    String lockName = "daily_cleanup";
    String instanceId = UUID.randomUUID().toString();
    
    try {
        // 尝试插入锁记录（表：task_lock，主键：lock_name）
        taskLockRepository.tryAcquire(lockName, instanceId, 60);
        doCleanup();
    } catch (DuplicateKeyException e) {
        // 已被其他实例持有，跳过
        return;
    } finally {
        taskLockRepository.release(lockName, instanceId);
    }
}

@Scheduled(fixedRate = 20000)
public void redisLockedTask() {
    String lockKey = "task:report";
    String lockValue = instanceId; // 唯一标识
    long expireTime = 30000; // 30秒

    Boolean locked = redisTemplate.opsForValue()
        .setIfAbsent(lockKey, lockValue, Duration.ofMillis(expireTime));

    if (Boolean.TRUE.equals(locked)) {
        try {
            generateReport();
        } finally {
            // Lua 脚本确保原子释放（防止误删他人锁）
            releaseLock(lockKey, lockValue);
        }
    }
}

# application.yml
spring:
  quartz:
    job-store-type: jdbc
    properties:
      org:
        quartz:
          scheduler:
            instanceName: MyClusteredScheduler
            instanceId: AUTO
          jobStore:
            class: org.quartz.impl.jdbcjobstore.JobStoreTX
            driverDelegateClass: org.quartz.impl.jdbcjobstore.PostgreSQLDelegate
            isClustered: true
            clusterCheckinInterval: 20000

// 调度中心每5分钟发一条消息
// 应用作为消费者，集群自动分片
@RabbitListener(queues = "scheduled.task.queue")
public void handleScheduledTask(Message msg) {
    executeBusinessLogic();
}