ava开源生鲜电商平台-购物车模块的设计与架构(源码可下载）
说明：任何一个电商无论是B2C还是B2B都有一个购物车模块，其中最重要的原因就是客户需要的东西放在一起，形成一个购物清单，确认是否有问题，然后再进行下单与付款.
1. 购物车数据库设计：
说明：业务需求：
1》购物车里面应该存放，那个买家，买了那个菜品的什么规格，有多少数量，然后这个菜品的加工方式如何。（如果存在加工方式的话，就会在这里显示处理。）
2》买家存在购物起送价。也就是用户放入购物车的商品的总价格如果低于配置的起送价，那么这个提交按钮就是灰色的。（不可能你点一个洋葱我们就送过去，成本太高。）
系统设计：
１. 购物车在买家APP上进行，这个时候是不需要跟后端API交互的，因为体验很差劲，用户在APP页面中不停的点击加菜以及菜的数量，如果根据后端进行交互，哪怕是每次请求是100ms，页面会存在很严重的抖动行为，速度快的话会出现卡顿，这个是不行的。
2. 在用户确定完成后，确认下单的时候，提交购物车，让后端可以存储用户购物车的数据。（确认下单过程）
3. 在用户去付款的时候，也就是提交了订单。这个时候再清理购物车。
相关后端代码如下：
/** * 购物车 */ @RestController @RequestMapping("/buyer/goodsCart") public class GoodsCartController extends BaseController{ private static final Logger logger = LoggerFactory.getLogger(GoodsCartController.class); @Autowired private GoodsCartService goodsCartService; @Autowired private GoodsFormatService goodsFormatService; /** * 生成购物车; * 1:先删除历史购物车; * 2:新增购物车数据; */ @RequestMapping(value="/commitCart",method={RequestMethod.GET,RequestMethod.POST}) public JsonResult commitCar(HttpServletRequest request, HttpServletResponse response,@RequestBody GoodsListVo goodsListVo) { try { List<GoodsCart> list = goodsListVo.getList(); if(null == goodsListVo.getUserId() || null == list){ return new JsonResult(JsonResultCode.FAILURE, "请求参数异常", ""); } for (int i = 0; i < list.size(); i++) { if(null ==list.get(i).getBuyerId() || null == list.get(i).getFormatId()){ return new JsonResult(JsonResultCode.FAILURE, "请求参数异常", ""); } } int result = goodsCartService.commitCart(list,goodsListVo.getUserId()); //更新购物车为空 则直接返回; if(list.size()<1){ return new JsonResult(JsonResultCode.SUCCESS, "更新成功", new ArrayList<>()); } Long buyerId = list.get(0).getBuyerId(); List<GoodsCartVo> goodsCartBuyers = goodsCartService.getGoodsCartBuyerId(buyerId); if (result == list.size()) { return new JsonResult(JsonResultCode.SUCCESS, "新增成功", goodsCartBuyers); } return new JsonResult(JsonResultCode.SUCCESS, "有下架商品", goodsCartBuyers); }catch(Exception e){ logger.error("[GoodsCartController][commitCart]",e); return new JsonResult(JsonResultCode.FAILURE, "系统错误,请稍后重试",""); } } /** * 对单个数据进行修改 新增 删除; * @param request * @param response * @param goodsCart * @return */ @RequestMapping(value="/updateCart",method={RequestMethod.GET,RequestMethod.POST}) public JsonResult updateCart(HttpServletRequest request, HttpServletResponse response,@RequestBody GoodsCart goodsCart) { try { BigDecimal goodsNumber=goodsCart.getGoodsNumber(); Long formartId=goodsCart.getFormatId(); BigDecimal count = goodsFormatService.getGoodsFormatById(formartId).getFormatPrice().multiply(goodsNumber); goodsCart.setCreateTime(new Date()); int result = goodsCartService.updateGoodsCart(goodsCart); if (result > 0) { return new JsonResult(JsonResultCode.SUCCESS, "操作成功", count); } return new JsonResult(JsonResultCode.FAILURE, "操作失败", count); }catch(Exception e){ logger.error("[GoodsCartController][updateCart]",e); return new JsonResult(JsonResultCode.FAILURE, "系统错误,请稍后重试",""); } } /** * * @param request * @param response * @param goodsCart * @return */ @RequestMapping(value="/insertCart",method={RequestMethod.GET,RequestMethod.POST}) public JsonResult insertCart(HttpServletRequest request, HttpServletResponse response,@RequestBody GoodsCart goodsCart) { try { BigDecimal goodsNumber=goodsCart.getGoodsNumber(); Long formartId=goodsCart.getFormatId(); BigDecimal count = goodsFormatService.getGoodsFormatById(formartId).getFormatPrice().multiply(goodsNumber); goodsCart.setCreateTime(new Date()); int result = goodsCartService.insertGoodsCart(goodsCart); if (result > 0) { return new JsonResult(JsonResultCode.SUCCESS, "操作成功", count); } return new JsonResult(JsonResultCode.FAILURE, "操作失败", count); }catch(Exception e){ logger.error("[GoodsCartController][insertCart]",e); return new JsonResult(JsonResultCode.FAILURE, "系统错误,请稍后重试",""); } } /** * 根据cartId 删除单个购物车项; * @param request * @param response * @param cartId * @return */ @RequestMapping(value="/deleteCart",method={RequestMethod.GET,RequestMethod.POST}) public JsonResult deleteCar(HttpServletRequest request, HttpServletResponse response, Long cartId) { try { if(null == cartId){ return new JsonResult(JsonResultCode.FAILURE, "请求参数异常", ""); } int result = goodsCartService.deleteGoodsCart(cartId); if (result > 0) { return new JsonResult(JsonResultCode.SUCCESS, "删除成功", ""); } else { return new JsonResult(JsonResultCode.FAILURE, "数据已不存在", ""); } }catch(Exception e){ logger.error("[GoodsCartController][deleteCart]",e); return new JsonResult(JsonResultCode.FAILURE, "系统错误,请稍后重试",""); } } @RequestMapping(value="/showCart",method={RequestMethod.GET,RequestMethod.POST}) public JsonResult showCart(HttpServletRequest request, HttpServletResponse response,@RequestBody GoodsListVo goodsListVo) { try { List<GoodsCart> list = goodsListVo.getList(); Long buyerId = goodsListVo.getUserId(); Long sellerId = goodsListVo.getSellerId(); if(null == buyerId ||null == sellerId){ return new JsonResult(JsonResultCode.FAILURE, "请求参数异常", ""); } goodsCartService.commitCartByBuyerIdSellerId(list,buyerId, sellerId); List<ProductVo> productVos = goodsCartService.getGoodsCartListBySellerId(buyerId, sellerId); return new JsonResult(JsonResultCode.SUCCESS, "查询成功", productVos); }catch(Exception e){ logger.error("[GoodsCartController][showCart]",e); return new JsonResult(JsonResultCode.FAILURE, "系统错误,请稍后重试",""); } } }