java web登录界面 源代码

大概流程:

java web项目中 导入sqljdbc4的包

java Resources中完成java代码

webContent 下建立一个存放自己写jsp的文件夹

sqljdbc4jstl-1.2 包粘贴载WEB-INF文件下的lib文件下。

java web 登录界面源代码

1.Data_uil.java

import java.sql.*;
public class Data_uil 
{
    public  Connection getConnection()
    {
        try{
            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
        }catch(ClassNotFoundException e)
        {
            e.printStackTrace();
        }
        String user="***";
        String password="***";
        String url="jdbc:sqlserver://127.0.0.1:1433;DatabaseName=***";
        Connection con=null;
        try{
            con=DriverManager.getConnection(url,user,password);
        }catch(SQLException e)
        {
            e.printStackTrace();
        }
        return con;
    }

    public  String selectPassword(String username)
    {
        Connection connection=getConnection();
        String sql="select *from login where username=?";
        PreparedStatement preparedStatement=null;
        ResultSet result=null;
        String password=null;
        try{
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setString(1,username);
            
            result=preparedStatement.executeQuery();//可执行的     查询
            if(result.next())
                password=result.getString("password");
                
        }catch(SQLException e){
            e.printStackTrace();
        }finally
        {
            close(preparedStatement);
            close(result);
            close(connection);
        }
        System.out.println("找到的数据库密码为:"+password);
        return password;    
    }
    public  void close (Connection con)
    {
        try{
            if(con!=null)
            {
                con.close();
            }
        }catch(SQLException e)
            {
                e.printStackTrace();
            }
    }
    public  void close (PreparedStatement preparedStatement)
    {
        try{
            if(preparedStatement!=null)
            {
                preparedStatement.close();
            }
        }catch(SQLException e)
        {
            e.printStackTrace();
        }
    }
    public  void close(ResultSet resultSet)
    {
        try{
            if(resultSet!=null)
            {
                resultSet.close();
            }
        }catch(SQLException e)
        {
            e.printStackTrace();
        }
    }
}

 2.login_check.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>验证用户密码</title>
</head>
<body>
<jsp:useBean id="util" class="util.Data_uil" scope="page" />
<%
    
    String username=(String)request.getParameter("username");
    String password=(String)request.getParameter("password");
    if(username==null||"".equals(username))
    {
        out.print("<script language='javaScript'> alert('用户名不能为空');</script>");
        response.setHeader("refresh", "0;url=user_login.jsp");
    }
    else
    {
        System.out.println("输入的用户名:"+username);
        String passwordInDataBase=util.selectPassword(username);
        System.out.println("密码:"+passwordInDataBase);
        
        if(passwordInDataBase==null||"".equals(passwordInDataBase))
        {
            out.print("<script language='javaScript'> alert('用户名不存在');</script>");
            response.setHeader("refresh", "0;url=user_login.jsp");
        }
        else if(passwordInDataBase.equals(password))
                {
                   out.print("<script language='javaScript'> alert('登录成功');</script>");
                   response.setHeader("refresh", "0;url=loginSucces.jsp");
                }
        else
        {
             out.print("<script language='javaScript'> alert('密码错误');</script>");
             response.setHeader("refresh", "0;url=user_login.jsp");
        }
    }
%>
</body>
</html>

3.loginSucces.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=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<hr size="10" width="26%" align="left" color="green">
  <font size="6" color="red" >登录成功 </font>
  <hr size="10" width="26%" align="left" color="green">
</body>
</html>

4.user_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=ISO-8859-1">
<title>登录界面</title>
</head>

<body  background="C:Userswin8workspaceLoginimage9dcbdc339e72a5663b5c289fb5573c13_10.jpg" >
    <center>
    <br><br><br><br><br><br>
    <h1 style="color:yellow">Login</h1>
    <br>
    <form name="loginForm" action="login_check.jsp" method="post">   
          <table Border="0" >
                    <tr >
                    
                        <td>账号</td>
                        <td><input type="text" name="username"></td>
                    </tr>
                    <tr>
                        <td>密码</td>
                        <td><input type="password" name="password">
                        </td>
                    </tr>
               </table>
               <br>
                <input type="submit" value="登录" style="color:#BC8F8F">
    </form>
    </center>

</body>
</html>

运行结果截图:

 

 

原文地址:https://www.cnblogs.com/ssyh/p/7886558.html