健身管理系统开发实战：消息通知、预约排队、售后工单模块

@Service
public class FitnessNotifyService {
    @Autowired
    private NotifyRecordMapper notifyRecordMapper;
    @Autowired
    private RabbitTemplate rabbitTemplate;

    public void sendNotify(NotifyEvent event) {
        // 幂等校验，防止重复发送
        LambdaQueryWrapper<NotifyRecord> wrapper = Wrappers.lambdaQuery();
        wrapper.eq(NotifyRecord::getBizKey, event.getBizKey());
        if (notifyRecordMapper.selectCount(wrapper) > 0) {
            return;
        }
        // 持久化通知记录
        NotifyRecord record = new NotifyRecord();
        record.setUserId(event.getUserId());
        record.setBizType(event.getBizType());
        record.setBizKey(event.getBizKey());
        record.setContent(event.getContent());
        record.setStatus(0);
        notifyRecordMapper.insert(record);
        // 投递消息队列异步推送
        rabbitTemplate.convertAndSend("fitness.notify.exchange", "notify.send", event);
    }
}

@Service
public class CourseBookingService {
    @Autowired
    private StringRedisTemplate redisTemplate;
    @Autowired
    private RedissonClient redissonClient;
    @Autowired
    private FitnessNotifyService notifyService;

    public void booking(Long courseId, Long userId) {
        String lockKey = "course:booking:lock:" + courseId;
        RLock lock = redissonClient.getLock(lockKey);
        try {
            lock.lock(5, TimeUnit.SECONDS);
            CourseInfo course = getCourseById(courseId);
            Long bookedCount = getBookedCount(courseId);
            if (bookedCount < course.getMaxNum()) {
                // 直接预约成功
                createBookingOrder(courseId, userId);
                notifyService.sendNotify(buildSuccessEvent(courseId, userId));
            } else {
                // 进入候补排队
                String queueKey = "course:wait:" + courseId;
                redisTemplate.opsForZSet().add(queueKey, userId.toString(), System.currentTimeMillis());
                notifyService.sendNotify(buildWaitEvent(courseId, userId));
            }
        } finally {
            if (lock.isHeldByCurrentThread()) {
                lock.unlock();
            }
        }
    }
}

@Service
public class WorkOrderService {
    @Autowired
    private WorkOrderMapper orderMapper;
    @Autowired
    private FitnessNotifyService notifyService;

    @Transactional(rollbackFor = Exception.class)
    public void changeStatus(Long orderId, Integer status, Long operatorId) {
        WorkOrder order = orderMapper.selectById(orderId);
        // 状态机校验，非法状态流转直接拦截
        if (!checkStatusFlow(order.getStatus(), status)) {
            throw new RuntimeException("工单状态流转不合法");
        }
        order.setStatus(status);
        order.setOperatorId(operatorId);
        orderMapper.updateById(order);
        // 状态变更触发通知
        notifyService.sendNotify(buildOrderEvent(order));
    }
}