十六、增加购物车商品数量

1 持久层

1. 规划SQL语句

   //更新t_cart表num值（加入购物车功能已有）
   //判断商品信息是否存在
   select * from t_cart where cid=#{cid}
   

2. 设计接口和抽象方法

   Cart findCartByCid(Integer cid);
   

3. 编写xml映射文件

   <select id="findCartByCid" resultMap="cart">
           select * from t_cart where cid=#{cid}
       </select>
   

2 业务层

1. 设计接口和抽象方法

   Integer addNum(Integer cid,Integer uid,String username);
   

2. 实现接口和抽象方法

   @Override
   public Integer addNum(Integer cid, Integer uid, String username) {
       Cart cart = cartMapper.findCartByCid(cid);
       if (cart == null){
           throw new CartNotFoundException("购物车商品信息不存在");
       }
       Integer num = cart.getNum()+1;
       Integer integer = cartMapper.updateCart(cid, num, username, new Date());
       if (integer != 1){
           throw new UpdateException("增加购物车商品数量时发生异常");
       }
       return num;
   }
   

3 控制层

1. 设计请求

   /url/{
        cid}/num/add
   post
   Integer cid,HttpSession session
   JsonResult<Integer>
   

2. 实现请求

@RequestMapping("{cid}/add/num")
public JsonResult<Integer> addNum(Integer cid,HttpSession session){
    Integer data = cartService.addNum(cid, getUidFromSession(session), getUsernameFromSession(session));
    return new JsonResult<>(OK,data);
}

十七、购物车结算

1 持久层

1. 规划SQL语句

   select 
   	cid,uid,pid,
   	t_cart.price,t_cart.num,
   	t_product.title,t_product.image,
   	t_product.price as realPrice
   from 
   	t_cart left join t_product on t_cart.pid=t_product.id
   where 
   	cid in (?,?,?)
   order by 
   	t_cart.craeted_time desc
   

2. 设计接口和抽象方法

   List<CartVO> findOVByCid(Integer[] cid);
   

3. 编写xml映射

       <select id="findOVByCid" resultType="com.cy.store.vo.CartVO">
           select
               cid,
               uid,
               pid,
               t_cart.price,
               t_cart.num,
               t_product.title,
               t_product.image,
               t_product.price as realPrice
           from
               t_cart left join t_product on t_cart.pid=t_product.id
           where
               cid in (
                   <foreach collection="array" item="cid" separator=",">
                       #{cid}
                   </foreach>
                   )
           order by
               t_cart.created_time desc
       </select>
   

2 业务层

1. 设计接口和抽象方法

   List<CartVO> getOVByCid(Integer uid,Integer[] cid);
   

2. 实现接口和方法

   @Override
       public List<CartVO> getOVByCid(Integer uid, Integer[] cid) {
           List<CartVO> list = cartMapper.findOVByCid(cid);
           Iterator<CartVO> it = list.iterator();
           while (it.hasNext()){
               CartVO cartVO = it.next();
               if (!cartVO.getUid().equals(uid)){
                   list.remove(cartVO);
               }
           }
           return list;
       }
   

3 控制层

1. 设计请求

   /carts/list
   POST
   Integer[] cid,HttpSession session
   JsonResult<List<CartOV>>
   

2. 实现请求

    @RequestMapping("list")
       public JsonResult<List<CartVO>> getCartList(Integer[] cid, HttpSession session){
           List<CartVO> data = cartService.getOVByCid(getUidFromSession(session), cid);
           return new JsonResult<>(OK,data);
       }
   

4 前端页面

//orderConfirm.html
<script type="text/javascript">
    $(document).ready(function (