jsp 实栗 jsp + jdbc 实现登录

实现思路

一个表单页,输入用户登录和密码,然后信息提交到jsp页面进行验证,如果可以服务器跳转到登录成功页,失败,跳转到错误页

跳转的时候窗口的URL地址会发生变化

代码如下

编写登录代码

登录

<!DOCTYPE html>
<html lang="zh_CN">
<head>
    <meta charset="UTF-8">
    <title>登录</title>
</head>
<body>
    <h1>登录操作</h1>
    <form action="login_check.jsp" method="post">
        <h1>用户登录</h1>
        <p>
            登录id
            <input type="text" name="id"/>
        </p>
        <p>
            登录密码
            <input type="password" name="password"/>
        </p>
        <input type="submit" value="登录"/>
        <input type="reset" value="重置"/>
    </form>
</body>
</html>

登录处理

<%@ page import="java.sql.*" %>
<%--
  Created by IntelliJ IDEA.
  User: ming
  Date: 19-3-9
  Time: 下午5:50
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<%!
    // 数据库驱动程序
    public static final String DBDRIVER = "com.mysql.cj.jdbc.Driver";
    // 数据库连接地址
    public static final String DBURL = "jdbc:mysql://47.94.95.84:32786/test";
    // 用户名
    public static final String DBUSER = "root";
    // 密码
    public static final String DBPASS = "ABCcba20170607";
%>
<%
    // 连接对象
    Connection connection = null;
    // 操作
    PreparedStatement preparedStatement = null;
    // 结果
    ResultSet resultSet = null;
    // 标志位
    boolean falge = false;
    // 用户真实姓名
    String name = null;
%>
<%
    try{
        Class.forName(DBDRIVER);
        // 获得连接
        connection = DriverManager.getConnection(DBURL, DBUSER, DBPASS);
        // 编写sql验证ID 密码
        String sql = "SELECT name FROM user WHERE userid = ? AND password = ?";
        // 实例化操作对象
        preparedStatement = connection.prepareStatement(sql);
        // 设置查询内容
        preparedStatement.setString(1, request.getParameter("id"));
        preparedStatement.setString(2, request.getParameter("password"));
        // 执行查询
        resultSet = preparedStatement.executeQuery();
        // 如果可以查询到,表示合法用户
        if(resultSet.next()){
            name = resultSet.getString(1);
            // 修改标志位
            falge = true;
        }
    }catch (Exception e){
        e.printStackTrace();
    }finally {
        try{
            resultSet.close();
            preparedStatement.close();
            connection.close();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
%>
<%
    // 登录成功
    if(falge){
    // 进行服务器端跳转
%>
    <jsp:forward page="./login_sucess.jsp">
        <jsp:param name="uname" value="<%=name%>"/>
    </jsp:forward>
<%
    }else{
%>
    <jsp:forward page="./login_failure.html"/>
<%        
    }
%>
</body>
</html>

登录完成

<%--
  Created by IntelliJ IDEA.
  User: ming
  Date: 19-3-9
  Time: 下午10:22
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>登录成功</h1>
<%=request.getParameter("uname")%>
</body>
</html>

登录失败

<%--
  Created by IntelliJ IDEA.
  User: ming
  Date: 19-3-9
  Time: 下午10:22
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>登录成功</h1>
<%=request.getParameter("uname")%>
</body>
</html>

效果演示

登录界面