jsp登陆校验演示 servlet、login、success

2019-10-27 17:59:31

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jsp的登录校验Demo

part_1: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>

part_2: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);  }  }

part_3: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CuoXin错新网。

注：相关教程知识阅读请移步到JSP教程频道。

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