//添加商品進購物車的方法
?private?boolean?addToCart(HttpServletRequest?request,?HttpServletResponse?response)
?{
??String?id?=?request.getParameter("id");
??String?number?=?request.getParameter("num");
??Items?item?=?idao.getItemsById(Integer.parseInt(id));
??
??//是否是第一次給購物車添加商品,需要給session中創建一個新的購物車對象
??if(request.getSession().getAttribute("cart")==null)
??{
???Cart?cart?=?new?Cart();
???request.getSession().setAttribute("cart",cart);
??}
??Cart?cart?=?(Cart)request.getSession().getAttribute("cart");
??if(cart.addGoodsInCart(item,?Integer.parseInt(number)))
??{
???return?true;
??}
??else
??{
???return?false;
??}
?}

Servlet部分么?
if(action.equals("add")) //如果是添加商品進購物車
???{
????if(addToCart(request,response))
????{
?????request.getRequestDispatcher("/success.jsp").forward(request, response);
????}
????else
????{
?????request.getRequestDispatcher("/failure.jsp").forward(request, response);
????}
???}

你看是不是?

可以把視頻暫停,自己打啊.....