登录案例代码实现和BeanUtils基本使用

登录案例代码实现

步骤：

1.创建项目，导入html页面，配置文件，jar包

html页面：中form表单的action路径的写法：

　　　　　　虚拟目录+Servlet的资源路径

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="" method="post">
        用户名:<input type="text" name="username"> <br>
        密码:<input type="password" name="password"><br>
        <input type="submit" value="登录">
    </form>
</body>
</html>

配置文件：（注意在src目录下）

driverClassName=com.mysql.cj.jdbc.Driver
#url=jdbc:mysql:///day14
url=jdbc:mysql://127.0.0.1:3306/day14
username=root
password=root
initialSize=5
maxActive=10
maxWait=3000

需要导入的包

2.创建数据库环境

MySQL的创建

CREATE DATABASE day14;

USE day14;

CREATE TABLE USER(
    id INT PRIMARY KEY AUTO_INCREMENT,
    username VARCHAR(32) UNIQUE NOT NULL,
    PASSWORD VARCHAR(32) NOT NULL
);

3.创建包 domain，创建类User

package pty.peng.web.domain;

/*
用户的实体类
 */
public class User {
    private int id;
    private String password;
    private String username;

    public User() {
    }

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

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getPassword() {
        return password;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", password='" + password + '\'' +
                ", username='" + username + '\'' +
                '}';
    }
}

4.工具类：

/*
JDBC的工具类 使用Durid连接池
 */
public class JDBCUtils1 {
    private static DataSource ds;

    static {
        Properties pro = new Properties();
        try {
            //加载配置文件
            pro.load(JDBCUtils1.class.getClassLoader().getResourceAsStream("druid.properties"));
            //获取DataSource
            ds = DruidDataSourceFactory.createDataSource(pro);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }


    /*
    获取连接池对象
     */
    public static DataSource getDataSource(){
        return ds;
    }

    /*
    获取连接Connection对象
     */
    public static Connection getConnection() throws SQLException {
        return ds.getConnection();
    }

}

5.创建包dao，创建类UserDao，提供login方法

/*
操作数据库中User表
 */
public class UserDao {
    //声明JDBCTemplate对象共用
    private JdbcTemplate template = new JdbcTemplate(JDBCUtils1.getDataSource());
    /**
     * 登录方法
     * @param loginUser 只要用户名和密码
     * @return 包含用户全部数据
     */
    public User login(User loginUser){
        try {
            //编写sql
            String sql = "select * from user where username = ? and password = ?";
            //调用query方法
            User user = template.queryForObject(sql, new BeanPropertyRowMapper<User>(User.class), loginUser.getUsername(), loginUser.getPassword());
            return user;
        } catch (DataAccessException e) {
            e.printStackTrace();
            return null;
        }
    }
}

测试类测试：

package com.peng.request.demo.web.test;

import com.peng.request.demo.web.dao.UserDao;
import com.peng.request.demo.web.domain.User;
import org.junit.Test;

public class UserDaoTest {
    @Test
    public void testlogin(){
        User loginUser = new User();
        loginUser.setUsername("superbaby");
        loginUser.setPassword("1231");

        UserDao dao = new UserDao();
        User user = dao.login(loginUser);
        System.out.println(user);
    }
}

6.编写servlet.LoginServlet类

package com.peng.request.demo.web.servlet;

import com.peng.request.demo.web.dao.UserDao;
import com.peng.request.demo.web.domain.User;

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 java.io.IOException;

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //设置编码
        req.setCharacterEncoding("utf-8");
        //获取请求参数
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        //封装user对象
        User loginUser = new User();
        loginUser.setUsername(username);
        loginUser.setPassword(password);
        //调用UserDao的login方法
        UserDao dao = new UserDao();
        User user = dao.login(loginUser);
        //判断user
        if (user==null){
            //登录失败
            req.getRequestDispatcher("/failServlet").forward(req,resp);
        }else {
            //登录成功
            //存储数据
            req.setAttribute("user",user);
            req.getRequestDispatcher("/successServlet").forward(req,resp);
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}

7.创建失败页面FailServlet:

package com.peng.request.demo.web.servlet;

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 java.io.IOException;

@WebServlet("/failServlet")
public class FailServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //给页面写一句话
        //设置编码
        response.setContentType("text/html;charset=utf-8");
        //输出
        response.getWriter().write("登录失败用户名或密码错误");
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

8.创建成功页面SuccessServlet:

package com.peng.request.demo.web.servlet;

import com.peng.request.demo.web.domain.User;

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 java.io.IOException;

@WebServlet("/successServlet")
public class SuccessServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取request域共享的user对象
        User user = (User) request.getAttribute("user");
        if (user!=null){
            //给页面写一句话
            //设置编码
            response.setContentType("text/html;charset=utf-8");
            //输出
            response.getWriter().write("登录成功!"+user.getUsername()+",欢迎您!");
        }
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

BeanUtils基本使用

9.BeanUtils工具类，简化数据封装

BeanUtils介绍：

　　BeanUtils工具类，简化数据封装

　　　　用于封装JavaBean的

　　1.JavaBean：标准的Java类

　　　　1.要求：

　　　　　　1.类必须被public修饰

　　　　　　2.必须提供空参的构造器

　　　　　　3.成员变量必须使用private修饰

　　　　　　4.提供公共setter和getter方法

　　　　2.功能：封装数据

　　2.概念：

　　　　成员变量：

　　　　属性：setter和getter方法截取后的产物

　　　　　　例如：getUsername()- ->Username - - > username

　　3.方法：

　　　　1.serProperty() 设置属性值

　　　　2.getProperty() 获取属性值

　　　　3.populate(Object obj，Map map)：将map集合的键值对信息，封装到对应的JavaBean对象中

操作的是属性（只是进行演示，最好不要这样编写）

    @Test
    public void test(){
        User user = new User();
        try {
            BeanUtils.setProperty(user,"hehe","male");
            System.out.println(user);

            String gender = BeanUtils.getProperty(user,"hehe");
            System.out.println(gender);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        }
    }

posted @ 2022-08-09 13:31 魔光领域阅读(36) 评论(0) 编辑收藏举报

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登录案例代码实现和BeanUtils基本使用

登录案例代码实现

BeanUtils基本使用

BeanUtils介绍：

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