cartservlet.java

在线购物系统,ajax+jsp实现

package com.accp.gz.th.zm.client.servlet;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import com.accp.gz.th.zm.client.javabean.PageBean;
import com.accp.gz.th.zm.client.javabean.CartBean;
import com.accp.gz.th.zm.server.entity.Goods;

public class CartServlet extends HttpServlet {
    private static final String CONTENT_TYPE = "text/html; charset=GBK";

    // 处理 Get 请求
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {
        response.setContentType(CONTENT_TYPE);

        // 1 获得用户选中的商品的ID
        int gid=Integer.parseInt(request.getParameter("gid"));

        // 2 根据商品ID取出相关信息，并封装到CartBean
        CartBean cartbean=new CartBean();

        HttpSession session=request.getSession();
        PageBean pagebean = (PageBean) session.getAttribute("pagebean");
        ArrayList datalist=pagebean.getDataList();

        for(int i=0; i<datalist.size(); i++){
            Goods goods=(Goods)datalist.get(i);
            if(goods.getId()==gid){
                cartbean.setId(gid);
                cartbean.setName(goods.getName());
                cartbean.setPrice(goods.getPrice());
            }
        }

        // 3 将CartBean实例放入购物车
        ArrayList cartlist=null;
        Object objCartList = session.getAttribute("cartlist");
        if(objCartList==null){
            cartlist=new ArrayList();
            session.setAttribute("cartlist",cartlist);
        }else{
            cartlist = (ArrayList)objCartList;
        }

        boolean flag=false;
        for(int i=0; i<cartlist.size(); i++){
            CartBean bean=(CartBean)cartlist.get(i);
            System.out.println(bean.getId()+" : "+gid);
            if(bean.getId()==gid){
                flag=true;
                break;
            }
        }

        if(!flag)
            cartlist.add(cartbean);

        // 4 转到购物车列表页面
        response.sendRedirect("/GoodsSysModule/jsp/CartList.jsp");
    }

    // 处理 Post 请求
    public void doPost(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {
        doGet(request, response);
    }

}