如何用Servlet+JDBC+MySQL+Jsp完成一个登陆注册界面

来源：互联网发布：php网站源码带数据库编辑：程序博客网时间：2024/06/11 22:59

有人问我如何用java的Servlet + JDBC + MySQL + Jsp完成一个功能简单的登录注册界面,

今天我就来写一下吧,写的不是很优美,大神轻喷~~~

工具:

Eclipse.

Navicat : 用来管理MySQL数据库

Firefox:用来调试页面

不多说,直接贴上代码吧~~~

首先,一个简简单单的Jsp登录界面(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=UTF-8"><style>body {top: 20%;text-align: center}.div {top: 50%;margin: auto;}</style><title>Insert title here</title>    <!--判断是否为空-->     <script type="text/javascript">        function login(form){            if(form.username.value == ""){                alert("用户不能为空！");                return false;            }            if(form.password.value == ""){                alert("密码不能为空！");                return false;            }        }    </script></head><body><h1>登录&注册</h1><hr><br><br><br><div class="div">         <form method="post" action="/ServletLogin/LoginServlet" onSubmit="return login(this);"><tr><td>用户名:</td><br><td><input type="text" name="username"></td></tr><br><br><br><tr><td>密码:</td><br><td><input type="password" name="password"></td></tr><br><br> <input type="submit" value="点击登录"  style="width: 120px; height: 33px; background: #ccc; color: black"></form></div><br><br><div id="Butten"><a href="zhuCe.jsp">还没有帐号??点击注册 ! !</a></div><br><br><a href="AboutMyWeb.jsp">关于我的网站</a></body></html>

然后,一个简简单单的注册界面:

<%@ page language="java" pageEncoding="utf-8"%><%@ page contentType="text/html;charset=utf-8"%><%request.setCharacterEncoding("UTF-8");response.setCharacterEncoding("UTF-8");response.setContentType("text/html; charset=utf-8");%><html><head>    <!--判断是否为空-->     <script type="text/javascript">        function login(form){            if(form.username.value == ""){                alert("ID不能为空！");                return false;            }            if(form.password1.value == ""){                alert("密码不能为空！");                return false;            }                        if(form.password1.value != form.password2.value){                alert("两次输入密码不一致!!!!！");                return false;            }        }    </script></head><body><center><h1>注册:</h1><HR>         <form method="post" action="/ServletLogin/zhuCe" onSubmit="return login(this);">         ID :<br> <input type="text" name="username" value="" /><br> 建议字母加上数字!! <br><br>密码 :<br> <input type="password" name="password1" value="" /> <br><br>再次输入密码 :<br> <input type="password" name="password2" value="" /> <br><br><input type="submit"value="点击注册" /></form></center></body></html>

下面,就要用Eclipse开始写java代码了:

---------------------------------------------------------------------------------------------------------------------------------------------

MySQL的配置:

package com.nantian.dao;import java.sql.*;public class DBDao {    private static String USER = "root";    private static String PASSWORD = "0000";    private static String DB_URL = "jdbc:mysql://localhost:3306/aaa";    private static String DB_DRIVER = "com.mysql.jdbc.Driver";//  private static String SQL = "";    private static Connection connection = null;    //连接数据库    public static Connection getConnection(){        try {            Class.forName(DB_DRIVER);            connection = DriverManager.getConnection(DB_URL, USER, PASSWORD);        } catch (Exception e) {            System.out.println("数据库连接异常");            e.printStackTrace();        }        return connection;    }    public  static void closeConnection(Connection connection){                    if(connection != null){                        try {                            connection.close(); // 关闭数据库连接                        } catch (SQLException e) {                            e.printStackTrace();                        }                    }                }    }

Dao层(UserDao.java):

package com.nantian.dao;import java.sql.Connection;import java.sql.ResultSet;import com.mysql.jdbc.PreparedStatement;import com.nantian.user.User;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;public class UserDao {    User user = null;    private String SQL ="";             public User login(String username, String password){        SQL = "select * from UserPWD where username = ? and password = ?";        Connection connection = null;        PreparedStatement pstmt = null;        try {            connection = DBDao.getConnection();            pstmt = (PreparedStatement) connection.prepareStatement(SQL);                        //这里的意思将用户名和密码填到SQL语句的问号处            pstmt.setString(1, username);            pstmt.setString(2, password);            ResultSet rSet = (ResultSet) pstmt.executeQuery();//得到数据库的查询结果,一个数据集            //判断结果集是否有效            if(rSet.next()){                user = new User();                user.setUsername(rSet.getString("username"));                user.setPassword(rSet.getString("password"));            }            connection.close();            pstmt.close();        } catch (Exception e) {            // TODO: handle exception            e.printStackTrace();        }finally{            DBDao.closeConnection(connection);        }        return user;    }        public User zhuCe(String username,String password){     SQL = "insert into userpwd values (?,?)";                  Connection connection = null;         PreparedStatement pstmt = null;         try {         connection = DBDao.getConnection();                               pstmt = (PreparedStatement) connection.prepareStatement(SQL);             pstmt.setString(1, username);             pstmt.setString(2, password);                          pstmt.execute();             connection.close();             pstmt.close();         } catch (Exception e) {             e.printStackTrace();         }finally{             DBDao.closeConnection(connection);         }         return user;         }        }

检测账户和密码是否正确,然后跳转:

package com.nantian.login.servlet;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.nantian.dao.UserDao;import com.nantian.user.User;public class LoginServlet extends HttpServlet {    public void doGet(HttpServletRequest request, HttpServletResponse response)  throws ServletException, IOException {        response.setCharacterEncoding("GBK");                //获取用户名和密码        String username = request.getParameter("username");        String password = request.getParameter("password");                //获取UserDao实例        UserDao userDao = new UserDao();        User user = userDao.login(username,password);        // 判断user是否为空        if(user != null){        // 转发到LoginSuccess.jsp页面        // getRequestDispatcher()是请求转发                request.getRequestDispatcher("LoginSuccess.jsp").forward(request, response);        }else{        // 登录失败            request.getRequestDispatcher("LoginFailed.jsp").forward(request, response);                }        }    public void doPost(HttpServletRequest request, HttpServletResponse response)     throws ServletException, IOException {        doGet(request, response);    }}

注册的servlet,用来跳转界面:

package com.nantian.login.servlet;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.nantian.dao.UserDao;import com.nantian.user.User;@WebServlet("/zhuCeServlet")public class zhuCeServlet extends HttpServlet {private static final long serialVersionUID = 1L;           public zhuCeServlet() {        super();    }protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {System.out.println("zhuCeServlet.java访问我啦");        response.setCharacterEncoding("GBK");                //获取用户名和密码        String username = request.getParameter("username");                System.out.println("username----->"+username);        String password = request.getParameter("password1");        System.out.println("password----->"+password);                //获取UserDao实例        UserDao userDao = new UserDao();        User user = userDao.zhuCe(username, password);        // 判断user是否为空        if(user != null){                 }else{        System.out.println("000000000000000000000");         request.getRequestDispatcher("zhuCeSS.jsp").forward(request, response);        }    }}

定义用户类(User):

package com.nantian.user;/* * 用户登录类，定义基本属性用户名和密码 */public class User {    private String username;    private String password;    public String getUsername(){        return this.username;    }    public void setUsername(String username){        this.username = username;    }    public String getPassword(){        return this.password;    }    public void setPassword(String password){        this.password = password;    }}

密码或者账户不正确,则跳转到这里:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>登录失败</title>    <meta http-equiv="pragma" content="no-cache">    <meta http-equiv="cache-control" content="no-cache">    <meta http-equiv="expires" content="0">        <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">    <meta http-equiv="description" content="This is my page">    <!--    <link rel="stylesheet" type="text/css" href="styles.css">    -->  </head>  <body>        登录失败，请返回重新登录 <br>        <!--注意此处的action中的路径写法-->        <form action="login.jsp">        <input type = "submit" value = "返回">        </form>  </body></html>

账户和密码都正确,则跳转到这里:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>登陆成功</title>    <meta http-equiv="pragma" content="no-cache">    <meta http-equiv="cache-control" content="no-cache">    <meta http-equiv="expires" content="0">        <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">    <meta http-equiv="description" content="This is my page">    <!--    <link rel="stylesheet" type="text/css" href="styles.css">    -->  </head>  <body><center><h1>登录成功!!!!</h1></center><hr>  </body></html>

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