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  • Java web 登录界面

    在安装完数据库和与eclipse进行连接之后,

    我们我们要编写一个java代码确定数据库已链接eclipse

    package pkg;
     
    import java.sql.Connection;
    import java.sql.DriverManager;
     
    public class Main {
     
     public static void main(String [] args)
     
     {
     
      String driverName="com.microsoft.sqlserver.jdbc.SQLServerDriver";
     
      String dbURL="jdbc:sqlserver://localhost:1433;DatabaseName=Text";
     
      String userName="sa";
     
      String userPwd="20153121";
     
      try
     
      {
     
       Class.forName(driverName);
     
       Connection ConnectiondbConn = DriverManager.getConnection(dbURL,userName,userPwd);
     
        System.out.println("连接数据库成功");
     
      }
     
      catch(Exception e)
     
      {
     
       e.printStackTrace();
     
       System.out.print("连接失败");
     
      }    
     
     }
     
    }
     
    登录界面的代码:

    <%@ page contentType="text/html; charset=gb2312" pageEncoding="UTF-8"%>
    <html>
    <head>
    <title>用户登录</title>
    </head>
    <body>
      <h2 align="center">用户登录</h2>
      <form name="form1" action="login_process.jsp" method="post"
      onsubmit="return isValidate(form1)">
      <table align="center" 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>
      <tr>
      <td></td>
      <td><input type="submit" value="登录"></td>
      </tr>
    </table>
    </form>
    </body>
    </html>

    <%@ page language="java" import="java.sql.*" 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>登录中</title>
    </head>
    <body>
    <%
    request.setCharacterEncoding("UTF-8");
    String driverStr = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
    String connStr = "jdbc:sqlserver://localhost:1433; DatabaseName=user";
    String dbusername = "sa";
    String dbpassword = "4980";

    Connection conn = null;
    PreparedStatement stmt = null;
    ResultSet rs = null;

    Class.forName(driverStr);
    conn = DriverManager.getConnection(connStr, dbusername, dbpassword);
    String sql = "select * from login where [username]=? and [password]=?";//定义一个查询语句
    stmt = conn.prepareStatement(sql);

    String user=(String)request.getParameter("username");
    String pass=(String)request.getParameter("password");//取出login.jsp的值
    stmt.setString(1, user);
    stmt.setString(2, pass);
    if(user.equals(""))
    {
    out.print("<script language='javaScript'> alert('账号为空');</script>");
    response.setHeader("refresh", "0;url=login.jsp");
    }
    else if(pass.equals(""))
    {
    out.print("<script language='javaScript'> alert('密码为空');</script>");
    response.setHeader("refresh", "0;url=login.jsp");
    }


    rs = stmt.executeQuery();
    if(rs.next())
    response.sendRedirect("login_success.jsp");
    else
    {
    out.print("<script language='javaScript'> alert('账号或密码错误');</script>");
    response.setHeader("refresh", "0;url=login.jsp");
    }

    stmt.close();
    conn.close();
    %>
    </body>
    </html>

    运行结果:

    错误时:

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  • 原文地址:https://www.cnblogs.com/gong123/p/6440557.html
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