简单登录系统-优快云博客

本文链接：https://blog.youkuaiyun.com/shiyi05/article/details/2426197

系统框架图如下：

三个文件如下：

//登录界面

/**

* @(#)Login.java

* @author shiyi05

* @version 1.00 2008/5/10

package com.rao;

import javax.servlet.http.*;

import java.io.*;

public class Login extends HttpServlet

{

public Login()

{

}

//处理Get请求

public void doGet(HttpServletRequest req,HttpServletResponse res)

{

try

{

//中文乱码

res.setContentType("text/html; charset=gbk");

PrintWriter pw=res.getWriter();

//返回登陆界面

pw.println("<html>");

pw.println("<body>");

pw.println("<h1>登陆界面</h1>");

pw.println("<form action=LoginCl method=post>");

pw.println("用户名: <input type=text name=username><br>");

pw.println("密码： <input type=password name=passwd><br>");

pw.println("<input type=submit value=loing><br>");

pw.println("</body>");

pw.println("</html>");

}

catch(Exception ex)

{

ex.printStackTrace();

}

public void doPost(HttpServletRequest req,HttpServletResponse res)

{

this.doGet(req,res);

}

//用户验证

/**

* @(#)LoginCl.java

* @author shiyi05

* @version 1.00 2008/5/10

package com.rao;

import javax.servlet.http.*;

import java.io.*;

public class LoginCl extends HttpServlet

{

public LoginCl()

{

}

//处理Get请求

public void doGet(HttpServletRequest req,HttpServletResponse res)

{

try

{

//中文乱码

res.setContentType("text/html; charset=gbk");

//接收用户名和密码

String u=req.getParameter("username");

String p=req.getParameter("passwd");

//验证

if(u.equals("sp") && p.equals("123"))

{

//合法

res.sendRedirect("Welcome");

}

else

{

//不合法

res.sendRedirect("Login");

}

catch(Exception ex)

{

ex.printStackTrace();

}

public void doPost(HttpServletRequest req,HttpServletResponse res)

{

this.doGet(req,res);

}

//欢迎界面

/** *//**

* @(#)Welcome.java

* @author shiyi05

* @version 1.00 2008/5/10

package com.rao;

import javax.servlet.http.*;

import java.io.*;

public class Welcome extends HttpServlet

...{

public Welcome()

...{

}

//处理Get请求

public void doGet(HttpServletRequest req,HttpServletResponse res)

...{

try

...{

//中文乱码

res.setContentType("text/html; charset=gbk");

PrintWriter pw=res.getWriter();

//返回登陆界面

pw.println("<html>");

pw.println("<body>");

pw.println("<h1>Welcome</h1>");

pw.println("</body>");

pw.println("</html>");

}

catch(Exception ex)

...{

ex.printStackTrace();

}

public void doPost(HttpServletRequest req,HttpServletResponse res)

...{

this.doGet(req,res);

}

一个简单的用户登陆系统