JSP登录案例

我就是我 2021-10-09 03:38 321阅读 0赞

编辑于２０１７圣诞节,加油

项目运行，在login.jsp处点击上方的绿色运行，或者右键项目run on server.

![20171225165603307][]

１．项目目录

直接把写好的前端目录整个复制到WebContent目录下(包括js和css文件夹，注意文件的相对路径)：

(自己写css文件时候，引入背景图片，image文件夹要相对于.css文件的位置写路径，而不是.html文件)

![20171225163131081][]

２．login.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Login</title> <link rel="stylesheet" type="text/css" href="css/style.css"> </head> <body> <div class="head"> <h1>欢迎访问</h1> </div> <div class="main"> <form action="dologin.jsp" method="post" class="form"> <p class="in"> <label>用户名</label> <input type="text" name="name" value=""> <label>密码</label> <input type="text" name="password" value=""> </p> <p class="space"> <input type="submit" name="submit" value="登录" class="login"> </p> </form> </div> </body> </html>

![20171225165035893][]

3.doLogin.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>dologin</title> </head> <body> <% request.setCharacterEncoding("utf-8"); //字符集使用utf-8编码，解决中文乱码 String name=request.getParameter("name"); String password = request.getParameter("password"); if("admin" .equals(name) && "admin".equals(password)){ //把对象绑定到会话上（直到关闭浏览器） session.setAttribute("loginuser",name); request.getRequestDispatcher("welcome.jsp").forward(request, response); }else{ response.sendRedirect("fail.jsp"); } %> </body> </html>

4.welcome.jsp登录成功页面

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>登录成功页面</title> <link rel="stylesheet" type="text/css" href="css/style.css"> </head> <body> <div class="head"> <h1>欢迎访问</h1> </div> <div class="main"> <% //防止登录名为空，会抛出异常 String loginuser = ""; 　　 if(session.getAttribute("loginuser")!= null){ loginuser = session.getAttribute("loginuser").toString();　//session获得绑定属性 } %> <h1>恭喜你<%=loginuser %>登录成功</h1> 姓名：<%=request.getParameter("name") %><br> 密码：<%=request.getParameter("password") %><br> 恭喜你<font color="red"><%=loginuser %></font>登录成功 <br> </div> </body> </html>

![20171225164919435][]

５．fail.jsp

![20171225164831531][]  
总结：

用到了

１．解决中文乱码：

request.setCharacterEncoding("utf-8"); /

２．JSP内置对象

request请求转发：request.getRequestDispatcher("welcome.jsp").forward(request,response);//登录成功，请求转发，（服务器端行为），地址栏的URL不会改变．

response请求重定向:response.sendRedirect("fail.jsp");//请求失败，(客户端行为)地址栏的地址会改变．

session会话技术，在浏览器关闭前会一直保存属性，置顶名称绑定对象：

session.setAttribute("loginuser",name); //dologin.jsp

session.getAttribute("loginuser"); //welcome.jsp

[20171225165603307]: /images/20211009/6544ce5847524e609b1dc0aba188d6c0.png
[20171225163131081]: /images/20211009/749c32c1b8c548bb921e9a71bcc3ba58.png
[20171225165035893]: /images/20211009/1dfec074b2724939b4b2b1995ea24edb.png
[20171225164919435]: /images/20211009/a28ead29824441d8baa9e9a420f74496.png
[20171225164831531]: /images/20211009/99923dce27c84e12bbcd95002a691b68.png