Jsp写的购物车代码

这是其中的一段代码,要项目的话加445899710
HttpSession session = request.getSession(false);

if(session==null){
dispatcher = request.getRequestDispatcher("show.jsp");
dispatcher.forward(request, response);
}

FoodBean foodBean = (FoodBean)session.getAttribute("FoodToAdd");
Map cart = (Map)session.getAttribute("cart");

if(cart==null){
cart = new HashMap();
session.setAttribute("cart", cart);
}

CartItemBean cartItem = (CartItemBean)cart.get(foodBean.getFoodID());
if(cartItem==null){
cart.put(foodBean.getFoodID(), new CartItemBean(foodBean,1));
}else{
cartItem.setNumber(cartItem.getNumber()+1);
}