2.05 购物车后台刷新并显示

一.用户登录添加商品使用cookie存入购物车，并把购物车商品传入到后台

步骤1：创建购物车BO对象

public class ShopcartBO {private String itemId;private String itemImgUrl;private String itemName;private String specId;private String specName;private Integer buyCounts;private String priceDiscount;private String priceNormal;//TODO get和set方法
}

步骤2：创建controller接口购物车数据

@Api(value = "购物车接口controller", tags = {"购物车接口相关的api"})
@RequestMapping("shopcart")
@RestController
public class ShopCatController {@ApiOperation(value = "添加商品到购物车", notes = "添加商品到购物车", httpMethod = "POST")@PostMapping("/add")public JSONResult add(@RequestParam String userId, @RequestBody ShopcartBO shopcartBO, HttpServletRequest request, HttpServletResponse response) {//判断用户id是否为空if (StringUtils.isBlank(userId)) {return JSONResult.errorMsg("");}System.out.println(shopcartBO);// TODO 前端用户在登录的情况下，添加商品到购物车，会同时在后端同步购物车到redis缓存return JSONResult.ok();}
}

二.根据用户购物车商品请求后台获取最新商品的价格到购物车页面
步骤1：创建购物车VO信息

public class ShopcartVO {private String itemId;private String itemImgUrl;private String itemName;private String specId;private String specName;private String priceDiscount;private String priceNormal;;
}

步骤2：对应mapper.xml中根据商品规格查询对应购物车VO信息

<select id="queryItemsBySpecIds" parameterType="List" resultType="com.imooc.pojo.vo.ShopcartVO">SELECTt_items.id as itemId,t_items.item_name as itemName,t_items_img.url as itemImgUrl,t_items_spec.id as specId,t_items_spec.`name` as specName,t_items_spec.price_discount as priceDiscount,t_items_spec.price_normal as priceNormalFROMitems_spec t_items_specLEFT JOINitems t_itemsONt_items.id = t_items_spec.item_idLEFT JOINitems_img t_items_imgont_items_img.item_id = t_items.idWHEREt_items_img.is_main = 1ANDt_items_spec.id IN<foreach collection="paramsList" index="index" item="specId" open="(" separator="," close=")">#{specId}</foreach>
</select>

步骤3：写mapper对应接口方法

public List queryItemsBySpecIds(@Param(“paramsList”) List specIdsList);

步骤4：创建service接口和实现类

/*** 根据规格ids查询最新的购物车中商品数据（用于刷新渲染购物车中的商品数据）* @param specIds* @return*/
public List<ShopcartVO> queryItemsBySpecIds(String specIds);

@Transactional(propagation = Propagation.SUPPORTS)
@Override
public List<ShopcartVO> queryItemsBySpecIds(String specIds) {String ids[] = specIds.split(",");List<String> specIdsList = new ArrayList<>();Collections.addAll(specIdsList, ids);return itemsMapperCustom.queryItemsBySpecIds(specIdsList);
}

步骤5：编写controller控制访问层

   // 用于用户长时间未登录网站，刷新购物车中的数据（主要是商品价格）@ApiOperation(value = "根据商品规格ids查找最新的商品数据", notes = "根据商品规格ids查找最新的商品数据", httpMethod = "GET")@GetMapping("/refresh")public JSONResult refresh(@ApiParam(name = "itemSpecIds", value = "拼接的规格ids", required = true, example = "1001,1003,1005")@RequestParam String itemSpecIds) {if (StringUtils.isBlank(itemSpecIds)) {return JSONResult.ok();}List<ShopcartVO> list = itemService.queryItemsBySpecIds(itemSpecIds);return JSONResult.ok(list);}