关于Session和Cookie 这里就不细说了，直接上代码说明网站中的"记住我"checkbox的应用
第一个Servlet
public class cookieServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
request.setCharacterEncoding("UTF-8");
PrintWriter out = response.getWriter();
String name = (String) request.getSession().getAttribute("userName");
if(name!=null&&!name.trim().equals("")){
out.print("欢迎你"+name);
}else{
out.print("请登陆");
}
System.out.println(request.getSession().getId()+"------get请求");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String checked = request.getParameter("me");
if(checked!=null){
Cookie ck = new Cookie("JSESSIONID",request.getSession().getId())
ck.setMaxAge(60*30);
ck.setPath("/");
response.addCookie(ck);
}
String userName = request.getParameter("userName");
if(userName!=null&&!userName.trim().equals("")){
request.getSession().setAttribute("userName", userName);
}
//doGet(request, response);
//禁用cookie url重写
//form 请求 但一共是两次请求 dopost中的session和doget中的session不是同 一个了已经
//response.sendRedirect(request.getContextPath()+"/cookieServlet");
System.out.println(request.getSession().getId()+"------post请求");
//url 重写
String url = response.encodeRedirectURL(request.getContextPath()+"/cookie Servlet");
response.sendRedirect(url);
}
}第二个Servlet
package com.test.cookie;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class TestCookieServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String name = (String) request.getSession().getAttribute("userName");
if(name!=null&&!name.trim().equals("")){
out.print("你是"+name+"-----TestCookieServlet");
}else{
out.print("你是没有名字-----TestCookieServlet");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
}
}一个jsp页面
<%@ page language="java" import="java.util.*" pageEncoding="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 ‘index.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">
-->
</head>
<body>
<!-- <form action="cookieServlet" method="post"> -->
<!--url重写 -->
<form action="<%=response.encodeURL("cookieServlet")%>" method="post">
<input type="text" name="userName"><br/>
<input type="checkbox" name="me" value="1">记住我
<input type="submit">
</form>
<br/>
<!-- <a href="cookieServlet"/>GOGO</a> -->
<!-- url 重写 -->
<a href="<%=response.encodeURL("cookieServlet")%>">GOGO</a>
</body>
</html>说明
1 正常情况下浏览器cookie是开启的，但是万一被禁用这里暂时使用了url重写 的方式解决，当然还有其它的方式。
2 个人测试的时候(火狐)即使禁用了cookie但还是可以正常访问，后来通过 firebug发现，cookie选项上选择禁用localhost的cookie就可以了。
3 这里关于cookie的配置，api就可以了都是有的而且解释很清楚。
本文出自 “探究web框架” 博客，请务必保留此出处http://itfei.blog.51cto.com/5513589/1747906
原文：http://itfei.blog.51cto.com/5513589/1747906