cartaction.java

用J2EE开发的网站,可以应用到图书馆,图书超市

package ksnb;
//对购物车的修改的类
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;

public class cartAction extends HttpServlet {
    private static final String CONTENT_TYPE = "text/html; charset=gb2312";
   private Hashtable h=null;
   String page=null;
    //Initialize global variables
    public void init() throws ServletException
    {

    }
    //Process the HTTP Get request
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {
        response.setContentType(CONTENT_TYPE);
        HttpSession session = request.getSession();
        FurnitureCart cart = (FurnitureCart) session.getAttribute("cart");
        String cmd = request.getParameter("cmd");
        System.out.println("cmd=" + cmd);
        int item=Integer.parseInt(request.getParameter("item"));//商品种类数
        //try块中的内容可以写再一个javabean中调用
        try {//清空
            if (cmd.equals("clean")) {
                h = cart.getHashtable();
                h.clear();
                System.out.println("clear");
                page="Cart.jsp";
            }
            //下订单OK
            if (cmd.equals("go")) {
                page="V_order.jsp";
            }
            //删除一项OK
            if(cmd.equals("del")){
                h=cart.getHashtable();
                String id=request.getParameter("id");
                System.out.println(id);
                if (h.containsKey(id)) {
                    System.out.println("id存在");
                    h.remove(id);
                }
               page="Cart.jsp";
            }
            //改变数量
            if (cmd.equals("change")) {
                System.out.println("change");
                h = cart.getHashtable();
                Enumeration e = h.keys();
                int i = 0;
                while (e.hasMoreElements()) {
                    if(i==item) break;//跳出循环
                    String count = request.getParameter("num" + i);
                    String idd = request.getParameter("id" + i);
                    if (h.containsKey(idd)) {

                        String[] tmpItem = (String[]) h.get(idd);

                        tmpItem[3] = count;//修改数量

                    }
                    i++;
                }
               page="Cart.jsp";
            }
        }catch(Exception e){
            System.out.println("gengxinyichang:"+e.toString());
        }
        RequestDispatcher rd=request.getRequestDispatcher(page);
        rd.forward(request,response);
    }
    public void destroy() {
    }
}