小购物车

	public ActionForward CartItmeAction(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response) {
		DynaActionForm dynaFrom = (DynaActionForm) form;
		// 食物的dbo
		Food f = (Food) dynaFrom.get("Food");
		FoodBiz foodbiz = new FoodBiz();
		// 购物车Map
		Food food = foodbiz.getFoodByFoodId(f.getFoodId());
		HttpSession session = request.getSession();
		Map cartMap = (Map) session.getAttribute("cartMap");
	
		// 如果没有创建购物车 就创建购物车
		if (cartMap == null) {
			cartMap = new HashMap();
			// 将购物车存到Session
			session.setAttribute("cartMap", cartMap);
		}
		// 获得购物车对象
		CartItemEntity cartentity = (CartItemEntity) cartMap.get(food
				.getFoodId());
		if (cartentity != null) {
			cartentity.setNum(cartentity.getNum() + 1);
		
		} else {
		
			cartMap.put(food.getFoodId(), new CartItemEntity(food, 1));
			
		}
		//迭代存到List
		Collection coll = cartMap.values();
		List list = new ArrayList();
		for (Iterator iter = coll.iterator(); iter.hasNext();) {
			CartItemEntity element = (CartItemEntity) iter.next();
			
			list.add(element);
		}
		
		request.setAttribute("cartList", list);
		
		return mapping.findForward("cartItem");
	}