第二十六天 jsp+servlet+mysql写的一个登录验证

来源：互联网发布：拉普拉斯矩阵编辑：程序博客网时间：2024/05/16 02:00

初学者，记录学习的点点滴滴；

验证码没搞出来，有点累，头疼！希望有大神指导，帮我搞一下这验证码。

总结一下吧：

1.用户输入是否为空，为空则显示用户名不能为空，

2.如果已经被注册过了，就显示已经注册过，请重新填写用户名。

3.密码是否为空，为空则显示不能为空。

验证从数据库获取的数据是否与表单获取的数据相同；

不同则显示，用户名或者密码错误；

其实都很简单。第一次写比较麻烦而已，我就是练练手而已。

1.User实体类

package com.entity;//映射数据库中表的字段名public class User {    private int id;    private String userName;    private String name;    private String sex;    private String pwd;        public User() {        super();        // TODO Auto-generated constructor stub    }    public User( String name,String userName,   String pwd,String sex) {        super();        this.userName = userName;        this.name = name;        this.sex = sex;        this.pwd = pwd;    }    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getUserName() {        return userName;    }    public void setUserName(String userName) {        this.userName = userName;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getSex() {        return sex;    }    public void setSex(String sex) {        this.sex = sex;    }    @Override    public int hashCode() {        final int prime = 31;        int result = 1;        result = prime * result + id;        result = prime * result + ((name == null) ? 0 : name.hashCode());        result = prime * result + ((sex == null) ? 0 : sex.hashCode());        result = prime * result + ((userName == null) ? 0 : userName.hashCode());        return result;    }    @Override    public boolean equals(Object obj) {        if (this == obj)            return true;        if (obj == null)            return false;        if (getClass() != obj.getClass())            return false;        User other = (User) obj;        if (id != other.id)            return false;        if (name == null) {            if (other.name != null)                return false;        } else if (!name.equals(other.name))            return false;        if (sex == null) {            if (other.sex != null)                return false;        } else if (!sex.equals(other.sex))            return false;        if (userName == null) {            if (other.userName != null)                return false;        } else if (!userName.equals(other.userName))            return false;        return true;    }    @Override    public String toString() {        return "User [id=" + id + ", userName=" + userName + ", name=" + name + ", sex=" + sex + "]";    }    public String getPwd() {        return pwd;    }    public void setPwd(String pwd) {        this.pwd = pwd;    }   }

2.数据库操作的接口和实现类

package com.dao;import java.sql.SQLException;import com.entity.User;//与数据库有关的操作的接口public interface UserDao {    //注册用户    public void add(User user) throws ClassNotFoundException, SQLException;    //用户登录    public User findByUser(String userName) throws SQLException, ClassNotFoundException;}

package com.dao;import java.sql.Connection;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import com.entity.User;import com.mysql.jdbc.PreparedStatement;import com.util.DBUtils;public class UserDaoImpl implements UserDao {    //用户增加    @Override    public void add(User user) throws ClassNotFoundException, SQLException {        // TODO Auto-generated method stub        Connection conn=DBUtils.getConn();        Statement st=conn.createStatement();        String sql="insert into t_user (name,userName,pwd,sex) values('"+user.getName()+"','"+user.getUserName()+"','"+user.getPwd()+"','"+user.getSex()+"')";        st.executeUpdate(sql);        DBUtils.CloseConn(conn);    }    @Override    public User findByUser(String userName) throws SQLException, ClassNotFoundException {        // TODO Auto-generated method stub        Connection conn=DBUtils.getConn();        String sql="select * from t_user where userName=?";        PreparedStatement ps=(PreparedStatement) conn.prepareStatement(sql);        ps.setString(1, userName);        ResultSet rs=ps.executeQuery();        User u = null;        while(rs.next()){            int id=rs.getInt(1);            String name=rs.getString(2);            String pwd=rs.getString(3);            String sex=rs.getString(4);               u=new User();               u.setId(id);               u.setName(name);               u.setPwd(pwd);               u.equals(sex);        }        return u;    }}

3.业务逻辑service接口和实现类

package com.service;import com.entity.User;public interface UserService {    public User findByUser(String userName);    public void add(User user);}

package com.service;import java.sql.SQLException;import com.dao.UserDao;import com.entity.User;public class UserServiceImpl implements UserDao {     private UserDao dao ;          public UserServiceImpl(UserDao dao) {        super();        this.dao = dao;    }    //增加用户的service     @Override    public void add(User user) throws ClassNotFoundException, SQLException {        // TODO Auto-generated method stub        dao.add(user);    }     public UserDao getDao() {        return dao;    }    public void setDao(UserDao dao) {        this.dao = dao;    }    //查找用户的额service    @Override    public User findByUser(String userName) throws SQLException, ClassNotFoundException {        // TODO Auto-generated method stub        return dao.findByUser(userName);    }}

4.util工具类

package com.util;import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;public class DBUtils {    //获取链接    public static Connection getConn() throws ClassNotFoundException{       Class.forName("com.mysql.jdbc.Driver");       Connection conn = null;    try {        conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test03?useUnicode=true&charactEncoding=gbk","root","1234");    } catch (SQLException e) {        // TODO Auto-generated catch block        e.printStackTrace();    }       return conn;    }    //关闭数据库    public static void CloseConn(Connection conn){        if(conn!=null){            try {                conn.close();            } catch (SQLException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        }    }}

5.servletweb层，负责转发给jsp

package com.web;import java.io.IOException;import java.sql.SQLException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import com.dao.UserDaoImpl;import com.entity.User;import com.service.UserServiceImpl;@SuppressWarnings("serial")public class UserServlet extends HttpServlet {    protected void service(HttpServletRequest request,HttpServletResponse response) throws IOException, ServletException{        //编码设置        request.setCharacterEncoding("GBK");        response.setContentType("text/html;charset=gbk");        String uri=request.getRequestURI();        String path=uri.substring(uri.lastIndexOf("/"),uri.lastIndexOf("."));        UserServiceImpl service= new UserServiceImpl(new UserDaoImpl());       //根据叠取的请求名转发到对用的页面    if(path.equals("/regist")){        String userName=request.getParameter("userName").trim();        String name=request.getParameter("name");        String pwd=request.getParameter("pwd").trim();        String sex=request.getParameter("sex");        //根据用户名查找用户是否存在，如果存在给一个提示，继续留在注册界面        if(userName.isEmpty()){            request.setAttribute("regist_err","用户名不能为空");            request.getRequestDispatcher("regist.jsp").forward(request, response);        }else if(pwd.isEmpty()){                request.setAttribute("regist_err1", "密码不能为空");                request.getRequestDispatcher("regist.jsp").forward(request, response);        }else{            User user = null;            try {                user = service.findByUser(userName);            } catch (ClassNotFoundException e) {                // TODO Auto-generated catch block                e.printStackTrace();            } catch (SQLException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }            if(user==null){                User u=new User(userName,name,pwd,sex);                try {                    service.add(u);                } catch (ClassNotFoundException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                } catch (SQLException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }                response.sendRedirect(request.getContextPath()+"/login.jsp");            }else{                request.setAttribute("regist_err", "用户名已经存在，请重新注册！");                request.getRequestDispatcher("regist.jsp").forward(request, response);            }        }    }else if(path.equals("/login")){            String userName=request.getParameter("userName");            String pwd=request.getParameter("pwd");            User user = null;            try {                user = service.findByUser(userName);            } catch (ClassNotFoundException e) {                // TODO Auto-generated catch block                e.printStackTrace();            } catch (SQLException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }            if(user!=null&&user.getPwd().equals(pwd)){                HttpSession session=request.getSession();                session.setAttribute("login_success",user);                response.sendRedirect(request.getContextPath()+"/index.jsp");             }else{                 request.setAttribute("login_err","用户名或者密码错误");                 request.getRequestDispatcher("/login.jsp").forward(request,response);             }    }    }}

6.注册+登录页面+登录成功会跳的页面

<%@ page language="java" import="java.util.*" pageEncoding="GBK" contentType="text/html; charset=GBK"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="<%=basePath%>">        <title>用户注册</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>  <h1>欢迎来到澳门博彩用户注册页面</h1><form action="regist.do" method="post"><table><tr><td>姓名：</td><td><input type="text" name="userName"/></td><%String str=(String)request.getAttribute("regist_err");String str1=(String)request.getAttribute("regist_err1"); %><td><%=str==null?"":str%><td></tr><tr><td>邀请码：</td><td><input type="text" name="name"/></td></tr><tr><td>密码：</td><td><input type="text" name="pwd"/></td><td><%=str1==null?"":str1%><td></tr><tr><td>性别： </td><td>男:<input type="radio"  name="sex" value="M" checked="checked"/>女:<input type="radio" name="sex" value="W"/></td></tr> <tr><td> <input type="submit" value="提交"/></td></tr></table></form>  </body></html>

<%@ page language="java" import="java.util.*" pageEncoding="GBK"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>        <title>My JSP 'login.jsp' starting page</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><h1>欢迎来到澳门博彩用户登录页面</h1><form action="login.do" method="post"><table><tr><td>用户名：</td><td><input type="text" name="userName"/></td><td> <%=request.getAttribute("login_err")==null?"":request.getAttribute("login_err") %></td></tr><tr><td>密码：</td><td><input type="text" name="pwd"/></td></tr><tr><td> <input type="submit" value="提交"/></td></tr></table></form>  </body></html>

<%@ page language="java" import="java.util.*" pageEncoding="GBK"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="<%=basePath%>">        <title>My JSP 'index.jsp' starting page</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>    This is my JSP page. <br>    <h1>  来玩呀，充100送100！、、、、、、</h1>  </body></html>

7.web,xml和sql

<?xml version="1.0" encoding="GBK"?><web-app xmlns="http://java.sun.com/xml/ns/javaee"   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"   version="2.5">     <servlet>   <servlet-name>myCode</servlet-name>   <servlet-class>com.web.CheckCodeServlet</servlet-class>    </servlet><servlet><servlet-name>userServlet</servlet-name><servlet-class>com.web.UserServlet</servlet-class></servlet><servlet-mapping><servlet-name>userServlet</servlet-name><url-pattern>*.do</url-pattern></servlet-mapping><servlet-mapping><servlet-name>myCode</servlet-name><url-pattern>/checkCode</url-pattern></servlet-mapping></web-app>

create database test03;create table t_user(id int primary key auto_increment,name varchar(20),userName varchar(20),pwd varchar(20),sex varchar(2));select * from t_user;

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