Jsp+Servlet+JDBC 登录案例

@2024/12/04 08:44

一、项目结构图

二、User 类

package Bean;

public class User {

    private int id;
    private String username;
    private String password;
    private String sex;
    private String email;
    private String birthday;

    public User() {
    }

    public User(int id, String username, String password, String sex, String email, String birthday) {
        this.id = id;
        this.username = username;
        this.password = password;
        this.sex = sex;
        this.email = email;
        this.birthday = birthday;
    }

    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 getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getBirthday() {
        return birthday;
    }

    public void setBirthday(String birthday) {
        this.birthday = birthday;
    }
}
​

三、UserDao 类

package Dao;

import Util.JDBCUtil;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class UserDao {


    ResultSet rs;
    PreparedStatement pstm;
    //登录
    public boolean Login(String name, String pwd)  {

        //调用 jdbc 连接
        Connection connection = JDBCUtil.getconnection();
        String sql = "select * from tb_user where username= ? and password = ?";
        try {
            //执行sql语句
            pstm=connection.prepareStatement(sql);
            //赋值
            pstm.setString(1, name);
            pstm.setString(2, pwd);
            //执行
            rs = pstm.executeQuery();
            if(rs.next()){
                return true;
            }

        } catch (SQLException e) {
            e.printStackTrace();
        }
        return  false;
    }
}
​

四、UserService

package Service;

import Dao.UserDao;

public class UserService {

    //实例化 UserDao
    private UserDao dao = new UserDao();

    //登录方法，UserService 调用 UserDao 中的 登录方法
    public boolean Login(String name, String pwd) {
        return dao.Login(name, pwd);
    }
}

​

五、UserServlet

1、UserServlet 类解析

​​

2、UserServlet 类

package Servlet;

import Service.UserService;
import jakarta.servlet.http.*;
import java.io.IOException;

public class UserServlet extends HttpServlet {

//实例化 UserService
private UserService userService = new UserService();

public UserServlet(){
super();
}

public void destroy(){
super.destroy();
}

public void doGet(HttpServletRequest request,HttpServletResponse response){
response.setContentType("text/html");
response.setCharacterEncoding("UTF-8");
}

public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException {
response.setContentType("text/html");
response.setCharacterEncoding("UTF-8");

//页面登录
String name = request.getParameter("username");
String password = request.getParameter("pwd");

if(userService.Login(name,password)){
response.sendRedirect("/UserManager_war_exploded/success.jsp");
}else {
response.sendRedirect("/UserManager_war_exploded/fail.jsp");
}

}

public void init() {
}

}
​

六、Util

package Util;

import java.sql.*;

public class JDBCUtil {

    //加载驱动
    static{
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    public static Connection getconnection() {
        String url="jdbc:mysql://localhost:3306/jdbc_demo?userUnicode=true&characterEncoding=utf8";
        String user="root";
        String password="abc123";
        Connection conn=null;

        try {
            conn=  DriverManager.getConnection(url,user,password);

        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
    //释放资源
    public static void release(ResultSet rs,PreparedStatement pstm,Connection conn){

        try{
            if(rs!=null){
                rs.close();
            }
            if(pstm!=null){
                pstm.close();
            }
            if(conn!=null){
                conn.close();
            }
        }catch (Exception e){
            e.printStackTrace();
        }
    }

}
​

七、web.xml 文件

1、web.xml 配置图解析

2、web 配置文件

<servlet>
	<servlet-name>UserServlet</servlet-name>
	<servlet-class>Servlet.UserServlet</servlet-class>
</servlet>

<servlet-mapping>
	<servlet-name>UserServlet</servlet-name>
	<url-pattern>/servlet/UserServlet</url-pattern>
</servlet-mapping>
​

八、页面

1、index.jsp 页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title><span data-type="inline-math" data-subtype="math" data-content="Title" contenteditable="false" class="render-node"></span></title>
</head>
<body>
	<form name="form" id="form" method="post" action="/UserManager_war_exploded/servlet/UserServlet">
	<p>用户名：<input type="text" name="username"></p>
	<p>密&nbsp;码：<input type="password" name="pwd"></p>
	<p>
	<input type="submit" value="提交">
	<input type="reset" value="重置">
	</p>
	</form>
</body>
</html>
​

2、success.jsp 页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
	<h1>登录成功</h1>
</body>
</html>
​

3、fail.jsp 页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
	<h>登录失败</h>
</body>
</html>
​