package com.estore.struts.action;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import org.apache.struts.action.ActionForm;import org.apache.struts.action.ActionForward;import org.apache.struts.action.ActionMapping;import org.apache.struts.actions.DispatchAction;import com.estore.struts.Globals;import com.estore.struts.entity.Cart;import com.estore.struts.entity.CartProduct;import com.estore.struts.entity.Product;import com.estore.struts.entity.User;import com.estore.struts.service.ProductService;import com.estore.struts.utils.ServiceFactory;public class CartAction extends DispatchAction {	public ActionForward addCart(ActionMapping mapping, ActionForm form,			HttpServletRequest request, HttpServletResponse response)			throws Exception {				/*		 * 在添加商品之前，會對session和user進行判斷，如果不存在時，會把錯誤信息封裝到request中，		 * 然后轉發(fā)出去讓用戶重新登錄；		 */		HttpSession session = request.getSession(false);		String message = "";		if (session == null) {			message = "該Session已經(jīng)過期,或者你沒有登錄,請重新<a href='/estore/pages/login.jsp' style='color:red;'>登錄</a>!請<a onclick='javascript:history.go(-1)' style='color:red;'>返回</a>!";			request.setAttribute("message", message);			return mapping.findForward("error");		}		User user = (User) session.getAttribute("user");		if (user == null) {			message = "該Session已經(jīng)過期,或者你沒有登錄,請重新<a href='/estore/pages/login.jsp' style='color:red;'>登錄</a>! 請<a onclick='javascript:history.go(-1)' style='color:red;'>返回</a>";			request.setAttribute("message", message);			return mapping.findForward("error");		}		/*		 * 從session中獲得購物車		 */		Cart cart = (Cart) session.getAttribute("cart");		if (cart == null) {			cart = new Cart();		}		/*		 * 從數(shù)據(jù)庫中把商品取到；		 */		ProductService productService = (ProductService) ServiceFactory				.getInstance().getService(Globals.PRODUCT_SERVICE);				Integer id = Integer.parseInt(request.getParameter("productid"));		Product product = productService.getProductById(id);				/*		 * 在向購物車中添加商品的時候會判斷商品是否已經(jīng)存在，		 * 已存在的就不讓在加入了；		 */		if (cart.isExist(id)) {			message = "該商品已經(jīng)存在!請<a onclick='javascript:history.go(-1)'>返回</a>!";			request.setAttribute("message", message);			return mapping.findForward("error");		} else {			/*			 * 向購物車添加一個商品；			 */			cart.addCart(product);			session.setAttribute("cart", cart);			return mapping.findForward("addcartsuccess");		}	}	public ActionForward remove(ActionMapping mapping, ActionForm form,			HttpServletRequest request, HttpServletResponse response)			throws Exception {				HttpSession session = request.getSession();		Integer productid = Integer.parseInt(request.getParameter("productid"));		ProductService productService = (ProductService) ServiceFactory		.getInstance().getService(Globals.PRODUCT_SERVICE);		Product pro = productService.getProductById(productid);		Cart cart = (Cart) session.getAttribute("cart");		cart.removeCart(pro);		session.setAttribute("cart", cart);		return mapping.findForward("removecartsuccess");	}	public ActionForward modify(ActionMapping mapping, ActionForm form,			HttpServletRequest request, HttpServletResponse response)			throws Exception {				Integer productid=Integer.parseInt(request.getParameter("productid"));		int num=Integer.parseInt(request.getParameter("num"));				HttpSession session = request.getSession();		Cart cart = (Cart) session.getAttribute("cart");		cart.modifyNum(productid, num);				return  mapping.findForward("modifycartsuccess");	}		/*	 * 也就是從session中把購物車清除掉；	 */	public ActionForward removeall(ActionMapping mapping, ActionForm form,			HttpServletRequest request, HttpServletResponse response)			throws Exception {				HttpSession session = request.getSession();		Cart cart = (Cart) session.getAttribute("cart");		session.removeAttribute("cart");		return mapping.findForward("success");	}}