使用Springboot和mybatis框架开发，已有写好的抽奖工具类BaseUtils,程序可能用到的表有活动表 t_raffle_info 奖品表 t_prize_info 活动和奖品关联表 t_raffle_prize_relation 奖品库存表 t_prize_stock 抽奖表 t_lottery_info 中奖表 t_lottery_win，给出抽奖功能的Controller层，Service层，Service实现类。实现抽奖功能 ：2.不在进行中的活动弹出提示 3.超过抽奖限制次数弹出提示 4限制接口频繁访问 10秒内不允许同一个用户访问2次 5抛出异常时事务需要回滚 6.需要校验用户是否存在，奖品是否存在，库存是否足够，否则给与提示

Controller层代码：

@RestController
@RequestMapping("/lottery")
public class LotteryController {

    @Autowired
    private LotteryService lotteryService;

    @PostMapping("/draw")
    public Result draw(@RequestParam("userId") String userId,
                       @RequestParam("activityId") String activityId) {
        try {
            lotteryService.draw(userId, activityId);
            return Result.success();
        } catch (Exception e) {
            e.printStackTrace();
            return Result.fail(e.getMessage());
        }
    }
}

Service层代码：

public interface LotteryService {

    void draw(String userId, String activityId) throws Exception;
}

Service实现类代码：

@Service
public class LotteryServiceImpl implements LotteryService {

    @Autowired
    private RaffleInfoMapper raffleInfoMapper;

    @Autowired
    private PrizeInfoMapper prizeInfoMapper;

    @Autowired
    private RafflePrizeRelationMapper rafflePrizeRelationMapper;

    @Autowired
    private PrizeStockMapper prizeStockMapper;

    @Autowired
    private LotteryInfoMapper lotteryInfoMapper;

    @Autowired
    private LotteryWinMapper lotteryWinMapper;

    @Autowired
    private BaseUtils baseUtils;

    @Override
    @Transactional(rollbackFor = Exception.class)
    public void draw(String userId, String activityId) throws Exception {
        // 1.判断活动状态
        RaffleInfo raffleInfo = raffleInfoMapper.selectByPrimaryKey(activityId);
        if (raffleInfo == null) {
            throw new Exception("活动不存在");
        }
        if (raffleInfo.getStatus() != 1) {
            throw new Exception("活动未进行中");
        }

        // 2.判断抽奖次数是否达到上限
        if (baseUtils.isLimitDraw(userId, activityId)) {
            throw new Exception("抽奖次数已达上限");
        }

        // 3.限制接口频繁访问
        if (baseUtils.isFrequentAccess(userId, "draw", 10)) {
            throw new Exception("操作过于频繁，请稍后再试");
        }

        // 4.校验用户是否存在，奖品是否存在，库存是否足够
        PrizeStock prizeStock = prizeStockMapper.selectByActivityId(activityId);
        if (prizeStock == null) {
            throw new Exception("奖品库存不存在");
        }
        PrizeInfo prizeInfo = prizeInfoMapper.selectByPrimaryKey(prizeStock.getPrizeId());
        if (prizeInfo == null) {
            throw new Exception("奖品不存在");
        }
        if (prizeStock.getStock() <= 0) {
            throw new Exception("奖品库存不足");
        }

        // 5.开始抽奖
        PrizeInfo drawPrize = baseUtils.draw(prizeInfo, rafflePrizeRelationMapper, prizeStockMapper, activityId);
        if (drawPrize == null) {
            throw new Exception("很遗憾，您未中奖");
        }

        // 6.记录抽奖信息
        LotteryInfo lotteryInfo = new LotteryInfo();
        lotteryInfo.setId(UUID.randomUUID().toString());
        lotteryInfo.setUserId(userId);
        lotteryInfo.setActivityId(activityId);
        lotteryInfo.setPrizeId(drawPrize.getId());
        lotteryInfoMapper.insert(lotteryInfo);

        // 7.将中奖信息记录到中奖表
        LotteryWin lotteryWin = new LotteryWin();
        lotteryWin.setId(UUID.randomUUID().toString());
        lotteryWin.setUserId(userId);
        lotteryWin.setActivityId(activityId);
        lotteryWin.setPrizeId(drawPrize.getId());
        lotteryWinMapper.insert(lotteryWin);
    }
}