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jsp登陆校验演示 servlet、login、success

时间：2020-04-07 01:10 编辑：来源：阅读：
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摘要：jsp登陆校验演示 servlet、login、success

jsp的登录校验Demo [b]part_1:[/b]login.jsp:登录页面:

<%@ 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 'Login.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> 
 
 <% 
 String fdbkMsg = (String) request.getAttribute("fdbkMsg"); 
 if (null == fdbkMsg) { 
 fdbkMsg = ""; 
 } 
 %> 
 
 <% 
 Boolean logedIn = (Boolean) session.getAttribute("logedIn"); 
 if (null == logedIn) { 
 logedIn = false; 
 } else if (logedIn) { 
 //如果在本次会话已经登陆，直接重定向到success-page-1 
 response 
  .sendRedirect("/ServletDemoProject/LOGIN-DEMO/success-page-1.jsp"); 
 } 
 %> 
 
 <% 
 String username = ""; 
 Cookie[] cookies = request.getCookies(); 
 if ((null != cookies) && (cookies.length > 0)) { 
 for (Cookie c : cookies) { 
 if ("admin".equals(c.getValue())) { 
  username = "admin"; 
  break; 
 } 
 } 
 }//end if-condition 
 %> 
 
 <body> 
 <br> 
 <div align="center"> 
 请登录: 
 <br> 
 <form action="/ServletDemoProject/servlet/LoginVerificationServlet" 
 method="post"> 
 用户名： 
 <input type="text" name="username" value="<%=username%>" /> 
 <br> 
 密 码： 
 <input type="password" name="password" value="" /> 
 <br> 
 <font color='red'><%=fdbkMsg%></font> 
 <br> 
 <input type="submit" value="提交" /> 
 <br> 
 </form> 
 </div> 
 </body> 
</html>

[b]part_2:[/b]LoginVerificationServlet.java:校验登录信息，此处没有连接数据库，默认只有username：admin，password：888888才算登录成功；登陆失败时：重新转发到Login.jsp并提示用户登陆失败，重新登陆；

package cn.mike.servlet.test_1209_Login; 
 
import java.io.IOException; 
 
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 LoginVerificationServlet extends HttpServlet { 
 
 private static final long serialVersionUID = -6886327892796230543L; 
 
 public void doGet(HttpServletRequest request, HttpServletResponse response) 
 throws ServletException, IOException { 
 String username = request.getParameter("username"); 
 String password = request.getParameter("password"); 
 if (("admin".equals(username)) && ("888888".equals(password))) {// 登录成功 
 // 保存cookie到客户端 
 Cookie userCookie = new Cookie("username", username); 
 userCookie.setMaxAge(60 * 2);// expiry : 2 minutes 
 response.addCookie(userCookie); 
 // 重定向到一个新的页面，并提示XXX用户登录成功（使用session存取用户名）; 
 request.getSession().setAttribute("username", username); 
 request.getSession().setAttribute("logedIn", true); 
 response 
  .sendRedirect("/ServletDemoProject/LOGIN-DEMO/success-page-1.jsp"); 
 } else {// 登陆失败 
 // 转发到登录界面，并提示错误信息： 
 request.setAttribute("fdbkMsg", "用户名或密码错误！"); 
 request.getRequestDispatcher("/LOGIN-DEMO/Login.jsp").forward( 
  request, response); 
 } 
 } 
 
 public void doPost(HttpServletRequest request, HttpServletResponse response) 
 throws ServletException, IOException { 
 
 // do same as GET-method : 
 doGet(request, response); 
 } 
 
}

[b]part_3:[/b]success-page-1.jsp:校验登录成功后重定向到该页面，提示用户已经成功登陆；如果用户试图通过不正当途径，e.g:从地址栏访问，将会转发到登录界面，并作提示；

<%@ 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 'success-page-1.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> 
 
 <% 
 String username = (String) session.getAttribute("username"); 
 if (null == username) { 
 //如果username为空值，说明不是通过正常渠道来的，转发到Login页面； 
 request.setAttribute("fdbkMsg", "别想走后门进来，赶紧登录！"); 
 request.getRequestDispatcher("/LOGIN-DEMO/Login.jsp").forward( 
  request, response); 
 } 
 %> 
 
 <body> 
 <br> 
 <%=username%>已经成功登陆。 
 <br> 
 <font>您可以选择浏览：</font> 
 <br> 
 <a href="/ServletDemoProject/LOGIN-DEMO/success-page-2.jsp">点这儿有精彩.</a> 
 <br> 
 <a href="/ServletDemoProject/LOGIN-DEMO/success-page-2.jsp">点这儿更精彩.</a> 
 <br /> 
 <a href="/ServletDemoProject/LOGIN-DEMO/success-page-2.jsp">你敢点这儿吗.</a> 
 <br /> 
 </body> 
</html>

part_4:success-page-2.jsp:登陆成功页面2，如果已经登陆成功将用户名保存到session，在访问该页面时将会校验一下，防止从地址栏暴力访问；

<%@ page language="java" import="java.util.Date" pageEncoding="UTF-8"%> 
<%@ page language="java" import="java.text.SimpleDateFormat"%> 
<% 
 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 'success-page-2.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> 
 
 <% 
 String username = (String) session.getAttribute("username"); 
 if (null == username) { 
 request.setAttribute("fdbkMsg", "呵呵嗒，这里是你来的地方吗？快登陆！"); 
 //转发到登录界面: 
 request.getRequestDispatcher("/LOGIN-DEMO/Login.jsp").forward( 
  request, response); 
 } 
 
 SimpleDateFormat sDateFormat = new SimpleDateFormat("a"); 
 Date today = new Date(); 
 String am_pm_str = sDateFormat.format(today); 
 String am_pm_str_in_chinese = ""; 
 if ("am".equalsIgnoreCase(am_pm_str)) { 
 am_pm_str_in_chinese = "上午"; 
 } else 
 am_pm_str_in_chinese = "下午"; 
 
 // set null; 
 sDateFormat = null; 
 today = null; 
 am_pm_str = null; 
 %> 
 
 <body> 
 <br /> 
 <font><b><%=username%><%=am_pm_str_in_chinese%>好，能来到页面2真不简单.</b> 
 </font> 
 </body> 
</html>

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持编程素材网。

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