Jsp+Servlet实现购物车功能

作者: 人生如梦何必自恋
来源: 51数据库
2020-08-07

这篇文章主要为大家详细介绍了Jsp+Servlet实现购物车功能，文中示例代码介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们可以参考一下

本文实例为大家分享了Servlet实现购物车功能的具体代码，供大家参考，具体内容如下

(1)用servlet实现简单的购物车系统，项目结构例如以下：（新建web Project项目仅仅须要AddItemServlet ， ListItemServlet。exam403.jsp三个文件就可以。其它的不用管）

（2）exam403.jsp代码例如以下：

<%@ page contentType="text/html; charset=utf-8" 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=utf-8" />
<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 >查看购物车</a></p>
</form>
</body>
</html>

（3）AddItemServlet代码例如以下：

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=utf-8");
  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();
  //将商品加入到购物车中
  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 //假设传入的商品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代码例如以下：

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=utf-8");
  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>");
  }
 }
 else
  out.print("购物车为空。"); 
  } 
  
protected void doPost(HttpServletRequest request,HttpServletResponse response)
        throws ServletException,java.io.IOException
 {
  doGet(request,response);
 }
}

（5）实现效果例如以下：

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

点击查看购物车：

OK！

简单的购物车到此结束！

以上就是本文的全部内容，希望对大家的学习有所帮助，