2.1 后端控制层
实现思路：
（1）从 cookie 中取出购物车
（2）向购物车添加商品
（3）将购物车存入 cookie
pinyougou-cart-web 工程新建 CartController.java

@RestController
@RequestMapping("/cart")public  class  CartController  {@Referenceprivate  CartService  cartService;@Autowiredprivate    HttpServletRequest  request;@Autowiredprivate    HttpServletResponse  response;/***购物车列表*@param  request*@return*/ @RequestMapping("/findCartList")
public  List<Cart>  findCartList(){String  cartListString  =  util.CookieUtil.getCookieValue(request, "cartList","UTF-8");if(cartListString==null  ||  cartListString.equals("")){ cartListString="[]";List<Cart>  cartList_cookie  =  JSON.parseArray(cartListString,  Cart.class);return  cartList_cookie;}/***添加商品到购物车*@param  request*@param  response*@param  itemId*@param  num*@return*/ @RequestMapping("/addGoodsToCartList")
public  Result  addGoodsToCartList(Long  itemId,Integer  num){try {List<Cart>  cartList  =findCartList();//获取购物车列表
cartList  =  cartService.addGoodsToCartList(cartList,  itemId,  num); util.CookieUtil.setCookie(request,  response,  "cartList",
JSON.toJSONString(cartList),3600*24,"UTF-8");return  new  Result(true,  "添加成功");}  catch  (Exception  e)  { e.printStackTrace();
return  new  Result(false,  "添加失败");}}

浏览器测试：
查看购物车：http://localhost:9105/cart/findCartList.do 添加商品到购物车 ：
http://localhost:9105/cart/addGoodsToCartList.do?itemId=1369280&num=100