session技术与cookie技术的区别:
Login.java中的代码:
package com.oracle.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URLEncoder;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Login extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//设置编码
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
//获取参数
String userName = request.getParameter("userName");
String pwd = request.getParameter("pwd");
String[] zt = request.getParameterValues("zt");
//保存Cookie
if(zt!=null && zt.length>0){
//实例化Cookie
Cookie c1 = new Cookie("username",URLEncoder.encode(userName,"utf-8"));
Cookie c2 = new Cookie("pwd",pwd);
//设置有效期
c1.setMaxAge(60*60*24);
c2.setMaxAge(60*60*24);
//保存Cookie
response.addCookie(c1);
response.addCookie(c2);
}else{
//不记录密码
Cookie[] cs = request.getCookies();
if(cs!=null && cs.length>0){
for (Cookie c : cs) {
if("username".equals(c.getName())){
c.setMaxAge(0);
response.addCookie(c);
}
if("pwd".equals(c.getName())){
c.setMaxAge(0);
response.addCookie(c);
}
}
}
}
PrintWriter out = response.getWriter();
out.print("登录成功");
}
}
index.jsp中的代码
<%@page import="java.net.URLDecoder"%>
<%@page import="java.net.URLEncoder"%>
<%@ 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 '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>
<%
String userName = "";
String pwd = "";
Cookie[] cs = request.getCookies();
if(cs!=null && cs.length>0){
for(Cookie c : cs){
if("username".equals(c.getName())){
userName = URLDecoder.decode(c.getValue(), "utf-8") ;
}
if("pwd".equals(c.getName())){
pwd = c.getValue();
}
}
}
%>
<form action="login" method="post">
账号:<input type="text" name="userName" value="<%=userName%>"><br>
密码:<input type="password" name="pwd" value="<%=pwd%>"><br>
<input type="checkbox" name="zt" value="1">记住密码<br>
<input type="submit" value="登录">
</form>
</body>
</html>