应用Servlet API中提供的Cookie类,用户把表单信息提交给Servlet后,在Servlet中获取用户请求的信息并添加到Cookie对象中,再通过HttpServletResponse对象把Cookie信息返回给客户端,在JSP页面中通过request内置对象来获取客户端的Cookie信息
在JSP中使用request对象获取的是一个Cookie对象的数组,需要循环中便利所有Cookie对象,并通过Cookie对象的getName()方法查找所有Cookie对象的名称,然后根据找到的Cookie名称获得Cookie对象中的值
- getComment()/setComment(String purpose) 获取/设置Cookie的注释
- getDomain()/setDomain(String pattern)
获取/设置Cookie适用的域。一般,Cookie只返回给与发送它的服务器名字完全相同的服务器 - getMaxAge()/setMaxAge(int expiry) 获取/设置Cookie过期之前的时间,以秒为单位
- getName()/setName(String name) 获取/设置Cookie的名字
- getValue()/setValue(String newValue) 获取/设置Cookie的值
- getPath()/setPath(String uri) 获取/设置Cookie适用的路径
创建Index.jsp页面
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@page import="java.net.URLDecoder"%>
<%
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>Cookie</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">
-->
<script type="text/javascript">
function a(){
var str="12345.6";
var s="";
for(var i=0;i<str.length;i++){
if(str.charCodeAt(i)>=48&&str.charCodeAt(i)<=57){
s=s+str[i];
}
}
alert(isNaN(12345));
if(s.length<str.length){
//alert(isNa);
}
}
</script>
<style type="text/css">
table{
font-size:14px;
font-family: 隶书;
color:gray;
border: 1px green solid;
}
input{
font-size:14px;
font-family: 隶书;
color:gray;
}
</style>
</head>
<body "a()">
<%
String userName=null; //用于保存从cookie中读取出的用户名
Cookie cookieArr[] = request.getCookies(); //获取客户端的所有Cookie
if(cookieArr!=null&&cookieArr.length>0){
for(Cookie c:cookieArr){
if(c.getName().equals("userName")){ //如果Cookie中有一个名为userName的Cookie
userName = URLDecoder.decode(c.getValue(),"UTF-8"); //获得此cookie的值
}
}
}
%>
<form action="cookieservlet" method="post">
<table align="center">
<tr>
<td>用户名:</td>
<td>
<input type="text" name="name" value="<%if(userName!=null){out.print(userName);}%>"/>
</td>
</tr>
<tr>
<td>密码:</td>
<td><input type="password" name="pwd" /></td>
</tr>
<tr>
<td colspan="2"><input type="submit" value="登 录" /></td>
</tr>
</table>
</form>
</body>
</html>
新建CookieServlet的Servlet类,doPost()方法中获取用户信息,添加到Cookie对象中并保存到客户端
public class CookieServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
String name = request.getParameter("name"); //获得用户名
name = java.net.URLEncoder.encode(name, "UTF-8"); //将用户名进行格式编码
//创建一个Cookie对象,并将用户名保存到Cookie对象中
Cookie nameCookie = new Cookie("userName", name);
//设置Cookie的有效时间,单位为秒
nameCookie.setMaxAge(60);
//通过response的addCookie()方法将此Cookie对象保存到客户端浏览器的Cookie中
response.addCookie(nameCookie);
request.getRequestDispatcher("success.jsp").forward(request, response);
}
}
web.xml文件配置
<servlet>
<servlet-name>CookieServlet</servlet-name>
<servlet-class>com.cn.zj.Servlet.CookieServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>CookieServlet</servlet-name>
<url-pattern>/cookieservlet</url-pattern>
</servlet-mapping>