1.介面實現的目標：
看到這個介面首先a.我們需要給前端，這三種不同情況下優惠券的數量—所以需要一個方法查詢這個memberId優惠券
b.我們需要各自狀態下的優惠券資訊的方法
c.未使用：即狀態為可用，使用結束時間比當前時間大（sql語句做判斷）
已使用：狀態為不可用，使用結束時間比當前時間大
已過期：狀態不可用，使用結束時間比當前時間小
現在我們開始實現他

2.控制層

 /**
     * 獲取使用者當前可用，已用，過期的已繫結的優惠券
    
     * @return
     */
    @ApiOperation(value = "優惠券各種狀態介面", notes = "優惠券狀態", produces = "application/json")
    @PostMapping("/couponList")
    public @ResponseBody BaseResponse<List<CouponUser>> getSellerCoupon(@RequestHeader(name = "Authorization", defaultValue = "token") String token,
                                                                        HttpServletRequest request,
                                                                        @RequestBody CouponMemberRequest couponMemberRequest) {

		//這段是獲取使用者的資訊    
		                                                                    
        String memberName = couponMemberRequest.getUserName();
        Integer state = couponMemberRequest.getState();//前端傳來的狀態1是可用，2是已使用，3是已過期
        ServiceResult<List<Member>> memberResult = memberService.getMemberByName(memberName);
        List<Member> members = memberResult.getResult();
        if (members.size() == 0) {
            return new BaseResponse<>(false, null, "使用者名稱或密碼錯誤！");
        } else if (members.size() > 1) {
            return new BaseResponse<>(false, null, "使用者名稱重複，請聯絡系統管理員！！");
        }
        Member member = members.get(0);




        Integer sellerId = couponMemberRequest.getSellerId();
        BaseResponse<List<CouponUser>> baseResponse = new BaseResponse<List<CouponUser>>();

        //如果狀態為1表示可用優惠券，那麼獲取狀態符合的優惠券資訊
        if (state != null && state == 1) {
            ServiceResult<List<CouponUser>> serviceResult = couponService
                .getEffectiveByMemberIdAndSellerId(member.getId(), sellerId);

            if (!serviceResult.getSuccess()) {
                baseResponse = new BaseResponse<List<CouponUser>>(false, null,
                    serviceResult.getMessage());
            }
            baseResponse.setData(serviceResult.getResult());
            baseResponse.setSuccess(true);
        }

        //如果狀態等於二表示已使用優惠券,支付介面記得把使用優惠券的狀態改了
        if (state != null && state == 2) {
            ServiceResult<List<CouponUser>> serviceResult = couponService
                .getDisEffectiveByMemberIdAndSellerId(member.getId(), sellerId);

            if (!serviceResult.getSuccess()) {
                baseResponse = new BaseResponse<List<CouponUser>>(false, null,
                    serviceResult.getMessage());
            }
            baseResponse.setData(serviceResult.getResult());
            baseResponse.setSuccess(true);
        }


        //如果狀態等於3表示已過期優惠券,支付介面記得把使用優惠券的狀態改了
        if (state != null && state == 3) {
            ServiceResult<List<CouponUser>> serviceResult = couponService
                .getOutEffectiveByMemberIdAndSellerId(member.getId(), sellerId);

            if (!serviceResult.getSuccess()) {
                baseResponse = new BaseResponse<List<CouponUser>>(false, null,
                    serviceResult.getMessage());
            }
            baseResponse.setData(serviceResult.getResult());
            baseResponse.setSuccess(true);
        }

        return baseResponse;
    }
 

2.服務層的介面

 public List<CouponUser> getCouponUsers(Map<String, String> queryMap, Integer start,
                                           Integer size) {
        List<CouponUser> couponUsers = couponUserReadDao.getCouponUsers(queryMap, start, size);
        this.setExtendAttr(couponUsers);
        return couponUsers;
    }


//設定拓展屬性
 private void setExtendAttr(List<CouponUser> couponUsers) {
        if (couponUsers != null && couponUsers.size() > 0) {
            // 儲存取到的商家資訊，避免多次讀取同一條資料，增加效率(下同理)
            Map<Integer, Seller> map = new HashMap<Integer, Seller>();
            Map<Integer, Coupon> couponMap = new HashMap<Integer, Coupon>();
            Map<Integer, Member> memberMap = new HashMap<Integer, Member>();
            for (CouponUser couponUser : couponUsers) {
                // 店鋪名稱
                if (map.get(couponUser.getSellerId()) != null) {
                    couponUser.setSellerName(map.get(couponUser.getSellerId()).getSellerName());
                } else {
                    Seller seller = sellerReadDao.get(couponUser.getSellerId());
                    if (seller != null) {
                        map.put(seller.getId(), seller);
                        couponUser.setSellerName(seller.getSellerName());
                    }
                }

                // 使用者名稱稱
                if (couponUser.getMemberId() > 0) {
                    if (memberMap.get(couponUser.getMemberId()) != null) {
                        couponUser.setMemberName(memberMap.get(couponUser.getMemberId()).getName());
                    } else {
                        Member member = memberReadDao.get(couponUser.getMemberId());
                        if (member != null) {
                            memberMap.put(member.getId(), member);
                            couponUser.setMemberName(member.getName());
                        }
                    }

                }
                // 優惠券名稱
                if (couponMap.get(couponUser.getCouponId()) != null) {
                    couponUser
                        .setCouponName(couponMap.get(couponUser.getCouponId()).getCouponName());
                    couponUser
                        .setCouponValue(couponMap.get(couponUser.getCouponId()).getCouponValue());
                    couponUser.setMinAmount(couponMap.get(couponUser.getCouponId()).getMinAmount());
                    couponUser.setChannel(couponMap.get(couponUser.getCouponId()).getChannel());
                } else {
                    Coupon coupon = couponReadDao.get(couponUser.getCouponId());
                    if (coupon != null) {
                        couponMap.put(coupon.getId(), coupon);
                        couponUser.setCouponName(coupon.getCouponName());
                        couponUser.setCouponValue(coupon.getCouponValue());
                        couponUser.setMinAmount(coupon.getMinAmount());
                        couponUser.setChannel(coupon.getChannel());
                    }
                }

                // 訂單序列號
                if (couponUser.getOrderId() > 0) {
                    Orders orders = ordersReadDao.get(couponUser.getOrderId());
                    if (orders != null) {
                        couponUser.setOrderSn(orders.getOrderSn());
                    }
                }
            }
        }
    }
 

3.mapper
lggt：老鐵幹他，小於大於

	<select id="getEffectiveByMemberIdAndSellerId" resultMap="CouponUserResult">
		select
		   *
		from `coupon_user`
		where `member_id` = #{memberId}
		and `seller_id` = #{sellerId}
		and `can_use` &gt; 0
		and `use_start_time` &lt; now()
		and `use_end_time` &gt; now()
	</select>