为什么我调用这个Servlet 会执行2次
qq_逆时针_1
2017-05-28 16:10
package servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.imooc.DAO.ItemsDao;
import com.imooc.model.Cart;
import com.imooc.model.Items;
/**
* Servlet implementation class CartServlet
*/
public class CartServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private String action;//表示购物车的动作
ItemsDao dao = new ItemsDao();
public CartServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
System.out.println("我是GRT ，我执行了");
response.setContentType("text/html; charset=utf-8" );
if (request.getParameter("action")!=null) {
this.action=request.getParameter("action");
if (action.equals("add")) {
if (addToCart(request,response)) {
request.getRequestDispatcher("../success.jsp").forward(request, response);
}else {
request.getRequestDispatcher("../failure.jsp").forward(request, response);
}
}else {
request.getRequestDispatcher("../cart.jsp").forward(request, response);
}
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
private boolean addToCart(HttpServletRequest request, HttpServletResponse response) {
// TODO Auto-generated method stub
String id = request.getParameter("id");
String number = request.getParameter("num");
Items item = dao.getItemsBYid(Integer.parseInt(id));
//判断是否是第一次加入购物车，需要给Session添加一个新的购物车对象
if (request.getSession().getAttribute("cart")==null) {
Cart cart = new Cart();
request.getSession().setAttribute("cart",cart);
}
Cart cart = (Cart) request.getSession().getAttribute("cart");
if (cart.addCommodity(item, Integer.parseInt(number))) {
return true;
}else {
return false;
}
}
}
输出结果
我是GRT ，我执行了
我是GRT ，我执行了
3回答
-
- 看着黎明庆幸
- 2018-03-07 18:41:00
同问？
-
- qq_逆时针_1
- 2017-06-01 21:26:07
<%@page import="java.net.URLDecoder"%>
<%@page import="java.net.URLEncoder"%>
<%@page import="com.imooc.model.Items"%>
<%@page import="com.imooc.DAO.ItemsDao"%>
<%@ page language="java" import="java.util.*" contentType="text/html; charset=utf-8" %><%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'details.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<link href="css/main.css" rel="stylesheet" type="text/css">
<script type="text/javascript" src="js/lhgcore.js"></script>
<script type="text/javascript" src="js/lhgdialog.js"></script>
<script type="text/javascript">
function selflog_show(id)
{
var num = document.getElementById("number").value;
J.dialog.get({id: 'haoyue_creat',title: '购物成功',width: 600,height:400, link: '<%=path%>/servlet/CartServlet?id='+id+'&num='+num+'&action=add', cover:true});
}
function add()
{
var num = parseInt(document.getElementById("number").value);
if(num<100)
{
document.getElementById("number").value = ++num;
}
}
function sub()
{
var num = parseInt(document.getElementById("number").value);
if(num>1)
{
document.getElementById("number").value = --num;
}
}
</script>
<style type="text/css">
hr{
border-color:FF7F00;
}
div{
float:left;
margin-left: 30px;
margin-right:30px;
margin-top: 5px;
margin-bottom: 5px;
}
div dd{
margin:0px;
font-size:10pt;
}
div dd.dd_name
{
color:blue;
}
div dd.dd_city
{
color:#000;
}
div #cart
{
margin:0px auto;
text-align:right;
}
span{
padding:0 2px;border:1px #c0c0c0 solid;cursor:pointer;
}
a{
text-decoration: none;
}
</style>
</head>
<body>
<h1>商品详情</h1>
<a href="index.jsp">首页</a> >> <a href="index.jsp">商品列表</a>
<hr>
<center>
<table width="750" height="60" cellpadding="0" cellspacing="0" border="0">
<tr>
<!-- 商品详情 -->
<%
ItemsDao itemDao = new ItemsDao();
Items item = itemDao.getItemsBYid(Integer.parseInt(request.getParameter("id")));
if(item!=null)
{
%>
<td width="70%" valign="top">
<table>
<tr>
<td rowspan="5"><img src="images/<%=item.getPicture()%>" width="200" height="160"/></td>
</tr>
<tr>
<td><B><%=item.getName() %></B></td>
</tr>
<tr>
<td>产地：<%=item.getCity()%></td>
</tr>
<tr>
<td>价格：<%=item.getPrice() %>￥</td>
</tr>
<tr>
<td>购买数量：<span id="sub" onclick="sub();">-</span><input type="text" id="number" name="number" value="1" size="2"/><span id="add" onclick="add();">+</span></td>
</tr>
</table>
<div id="cart">
<img src="images/buy_now.png"><a href="javascript:selflog_show(<%=item.getId()%>)"><img src="images/in_cart.png"></a><a href="servlet/CartServlet?action=show"><img src="images/view_cart.jpg"/></a>
</div>
</td>
<%
}
%>
<%
String list ="";
//从客户端获得Cookies集合
Cookie[] cookies = request.getCookies();
//遍历这个Cookies集合
if(cookies!=null&&cookies.length>0)
{
for(Cookie c:cookies)
{
if(c.getName().equals("ListViewCookie"))
{
list = URLDecoder.decode(c.getValue(), "UTF-8");
}
}
}
list+=request.getParameter("id")+",";
//如果浏览记录超过1000条，清零.
String[] arr = list.split(",");
if(arr!=null&&arr.length>0)
{
if(arr.length>=1000)
{
list="";
}
}
Cookie cookie = new Cookie("ListViewCookie",URLEncoder.encode(list, "UTF-8"));
response.addCookie(cookie);
%>
<!-- 浏览过的商品 -->
<td width="30%" bgcolor="#EEE" align="center">
<br>
<b><font color="#FF7F00">您浏览过的商品</font></b><br>
<!-- 循环开始 -->
<%
ArrayList<Items> itemlist = itemDao.getViewList(list);
if(itemlist!=null&&itemlist.size()>0 )
{
for(Items i:itemlist)
{
%>
<div>
<dl>
<dt>
<a href="details.jsp?id=<%=i.getId()%>"><img src="images/<%=i.getPicture() %>" width="120" height="90" border="1"/></a>
</dt>
<dd class="dd_name"><%=i.getName() %></dd>
<dd class="dd_city">产地:<%=i.getCity() %> 价格:<%=i.getPrice() %> ￥ </dd>
</dl>
</div>
<%
}
}
%>
<!-- 循环结束 -->
</td>
</tr>
</table>
</center>
</body>
</html> -
- 慕粉3796571
- 2017-06-01 20:38:20
去看看jsp那边是不是请求2次；你这个Servlet看起来没问题。
JAVA遇见HTML——Servlet篇
160615 学习 · 1029 问题
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