servlet方式通过Cookie记住登录时的用户名和密码 - 映日残阳

1.建立web工程

2.创建存放servlet的包

3右键包，新建servlet，路径将前面的servlet去掉，只需要doPost和doGet方法

编写servlet

CookieServlet.java代码如下：

package test1029;

import java.io.IOException;
import java.io.PrintWriter;

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 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 {
        response.setContentType("text/html");
        
        String uname=request.getParameter("uname");
        String password=request.getParameter("password");
        String ck=request.getParameter("ck");
        
        //被选中的状态是on 没有被选中的状态下是null
        if("on".equals(ck)){
        //构造Cookie对象
        //添加到Cookie中
        Cookie c=new Cookie("users", uname+"-"+password);
        
        //设置过期时间
        c.setMaxAge(600);
        
        //存储
        response.addCookie(c);
    }
    }
}

配置文件web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>test1029</display-name>
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>CookieServlet</servlet-name>
    <servlet-class>test1029.CookieServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>CookieServlet</servlet-name>
    <url-pattern>/CookieServlet</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
</web-app>

index.jsp代码：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<%

//el表达式
String names="";
String pwd="";
//取出Cookie
Cookie [] c=request.getCookies();
for(int i=0;i<c.length;i++){
    if(c[i].getName().equals("users")){
        //存着数据（用户名+密码）
        names=c[i].getValue().split("-")[0];
        pwd=c[i].getValue().split("-")[1];
        
        //再一次的存起来（备用）
        request.setAttribute("xingming",names);
        request.setAttribute("mima", pwd);
    }
}

 %>

<!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">
        用户名:<input type="text" name="uname" id="uname" value="${xingming}"/><br>
        密码:<input type="password" name="password" id="password" value="${mima }"/><br>
        <input type="checkbox" name="ck">记住用户名和密码<br>
        <input type="submit" value="登录">
    </form>
  </body>
</html>

效果图：

1、项目运行之后，先进入登录界面，填写用户名和密码，效果如下图

2.登录后：

3.重新访问登录页面，效果如下：

posted on 2015-10-30 18:05 映日残阳阅读(15316) 评论(2) 编辑收藏举报

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