Servlet/Jsp实现购物车

article/2025/10/17 22:43:09

(1)用servlet实现简单的购物车系统，项目结构如下：（新建web Project项目只需要AddItemServlet ， ListItemServlet，exam403.jsp三个文件即可，其他的不用管）

（2）exam403.jsp代码如下：

<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
</head><body>
<form id="form1" name="form1" method="post" action="/servletProject/addItem"><label></label>商品:<select name="itemID" id="itemID"><option value="洗衣粉">洗衣粉</option><option value="香皂">香皂</option><option value="食用油">食用油</option></select><p>数量:<label><input name="quantity" type="text" id="quantity" value="1" /></label><label><input type="submit" name="Submit" value="提交" /></label><a href="/servletProject/listItem">查看购物车</a></p>
</form>
</body>
</html>

（3）AddItemServlet代码如下：

package com.lc.shoppingCar;import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
public class AddItemServlet extends HttpServlet 
{  protected void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,java.io.IOException{ServletContext application=getServletContext() ;ServletConfig config=getServletConfig() ;response.setContentType("text/html;charset=gb2312");PrintWriter out=response.getWriter(); HttpSession session =request.getSession();request.setCharacterEncoding("gb2312");//读取表单传入的商品ID及数量String id=request.getParameter("itemID"); String num=request.getParameter("quantity");if(id!=null && num.length()!=0){  //从Sessionn中读取购物车HashMap shoppingCar=(HashMap)session.getAttribute("shoppingCar");if(shoppingCar==null)shoppingCar=new HashMap();//将商品添加到购物车中String onum=(String)shoppingCar.get(id);if(onum==null)shoppingCar.put(id,num);else{int n1=Integer.parseInt(num);int n2=Integer.parseInt(onum);String result=String.valueOf(n1+n2);shoppingCar.put(id,result);}   //将购物车写回session中保存session.setAttribute("shoppingCar",shoppingCar); }else  //如果传入的商品ID号为空或数量为空，显示提示信息System.out.print("商品ID号为空会或数量为空！");//返回商品列表页response.sendRedirect("/servletProject/exam403.jsp");   }	protected void doPost(HttpServletRequest request,HttpServletResponse response)throws ServletException,java.io.IOException{doGet(request,response);}
}

（4）ListItemServlet代码如下：

package com.lc.shoppingCar;import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
public class ListItemServlet extends HttpServlet 
{  protected void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,java.io.IOException{ServletContext application=getServletContext() ;ServletConfig config=getServletConfig() ;response.setContentType("text/html;charset=gb2312");PrintWriter out=response.getWriter(); HttpSession session =request.getSession();request.setCharacterEncoding("gb2312");//从session中获取购物车HashMap shoppingCar=(HashMap)session.getAttribute("shoppingCar");//显示购物车中的内容if(shoppingCar!=null){Set show=shoppingCar.entrySet();Iterator it=show.iterator();while(it.hasNext()){out.print(it.next()+"<br>");}}elseout.print("购物车为空！"); }	protected void doPost(HttpServletRequest request,HttpServletResponse response)throws ServletException,java.io.IOException{doGet(request,response);}
}

（5）实现效果如下：

访问：http://localhost:8080/servletProject/exam403.jsp 学则商品提交