数据库链接的WEB登陆界面的实现

时间 2019-11-19

标签数据库链接 web 登陆界面实现栏目 SQL 繁體版

原文原文链接

要实现此功能，须要电脑安装JAVA EE、SQL Server 2008和Tomcat等软件，并进行配置环境成功。html

对这门课的但愿和本身的目标：java

但愿：能够彻底掌握老师所讲的内容。sql

目标：可以完整的作出一个网站。数据库

计划每周花多少时间在这门课上：jsp

每周的天天均尽可能花1个小时的时间在敲代码上。sqlserver

接下来~post

1、首先须要建立数据库，并在数据库中建立数据表，列表以下：网站

建成以后的数据表如图所示：ui

2、而后，打开JAVA EE，开始建立WEB项目。url

3、建立jsp文件，以下：

<%@ page import="java.sql.*" 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>登陆界面</title>
</head>
<body>
    <center>
        <h1 style="color:red">登陆</h1>
            <form id="indexform" name="indexForm" action="logincheck.jsp" method="post">
                <table border="0">
                    <tr>
                        <td>帐号：</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="登陆" style="color:#BC8F8F">
            </form>
    </center>
</body>
</html>

logincheck.jsp

<%@ page import="java.sql.*" 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>Insert title here</title>
</head>
<body>
<jsp:useBean id="db" class="Bean.DBBean" scope="page"/>
<%
    request.setCharacterEncoding("UTF-8");
    String username=(String)request.getParameter("username");
    String password=(String)request.getParameter("password");//取出login.jsp的值
    
    
    //下面是数据库操做 *表明全部值
    String sql="select * from lhT where username="+"'"+username+"'";//定义一个查询语句
    ResultSet rs=db.executeQuery(sql);//运行上面的语句
    if(rs.next())
    {
        /* if(password.equals(rs.getString(2)))
        {
            
        } */
        if(password.equals(rs.getObject("password"))){
            response.sendRedirect("loginsuccess.jsp");
        }
        else{
            out.print("<script language='javaScript'> alert('密码错误');</script>");
            response.setHeader("refresh", "0;url=login.jsp");
        }
    }
    else 
    {
        out.print("<script language='javaScript'> alert('请输入用户名——else');</script>");
        response.setHeader("refresh", "0;url=login.jsp");
    }
    
%>
</body>
</html>

loginsuccess.jsp

<%@ page import="java.sql.*" 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>
<h1>登陆成功 </h1>
</body>
</html>

4、而后是其余文件的建立：

建立DBBean.java,链接数据库

package Bean;
import java.sql.*;
public class DBBean {
    private String driverStr = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
    private String connStr = "jdbc:sqlserver://localhost:1433; DatabaseName=lhsjk";
    private String dbusername = "ABC";
    private String dbpassword = "123";
    private Connection conn = null;
    private Statement stmt = null;

    public DBBean()
    {
        try
        {
            Class.forName(driverStr);
            conn = DriverManager.getConnection(connStr, dbusername, dbpassword);
            stmt = conn.createStatement();
        } 
        catch (Exception ex) {
            System.out.println(ex.getMessage());
            System.out.println("数据链接失败！");
        } 
        
    }

    public int executeUpdate(String s) {
        int result = 0;
        System.out.println("--更新语句:"+s+"\n");
        try {
            result = stmt.executeUpdate(s);
        } catch (Exception ex) {
            System.out.println("执行更新错误！");
        }
        return result;
    }

    public ResultSet executeQuery(String s) {
        ResultSet rs = null;
        System.out.print("--查询语句:"+s+"\n");
        try {
            rs = stmt.executeQuery(s);
        } catch (Exception ex) {
            System.out.println("ִ执行查询错误！");
        }
        return rs;
    }
    public void execQuery(String s){
        try {
            stmt.executeUpdate(s);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            System.out.println("执行插入错误！");
        }
    }

    public void close() {
        try {
            stmt.close();
            conn.close();
        } catch (Exception e) {
        }
    }
}

而后是其余的，列表以下：

5、运行。

主页面：

登陆成功时：

登陆失败时（包括用户名错误，密码错误）