0512实训作业

0x01 登入模块代码实现

创建User实体类

package ruanko.newspublish.entity;

public class Users {
    private int uid;
    private String username;
    private String password;

    public Users(){}
    public Users(int uid, String username, String password) {
        this.uid = uid;
        this.username = username;
        this.password = password;
    }

    public int getUid() {
        return uid;
    }

    public void setUid(int uid) {
        this.uid = uid;
    }

    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;
    }

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

创建存放User数据的数据库table

-- ----------------------------
-- Table structure for users
-- ----------------------------
DROP TABLE IF EXISTS `users`;
CREATE TABLE `users` (
  `uid` int unsigned NOT NULL AUTO_INCREMENT,
  `username` varchar(255) NOT NULL,
  `password` varchar(255) NOT NULL,
  PRIMARY KEY (`uid`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;

-- ----------------------------
-- Records of users
-- ----------------------------
BEGIN;
INSERT INTO `users` VALUES (1, 'admin', '21232f297a57a5a743894a0e4a801fc3');
COMMIT;

创建login.jsp文件

<%--
  Created by IntelliJ IDEA.
  User: q1jun
  Date: 2022/5/11
  Time: 17:19
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html>
<head>
    <base href="<%=basePath%>">
    <title>登入</title>
    <script type="text/javascript" src="js/weui.min.js" language="JavaScript"></script>
    <link href="css/weui.css" type="text/css" rel="stylesheet">
</head>
<body data-weui-theme="light">
<form class="weui-cells" action="login" method="post">
    <label for="js_input1" class="weui-cell weui-cell_active">
        <div class="weui-cell__hd"><span class="weui-label">用户名</span></div>
        <div class="weui-cell__bd">
            <input name="username" id="js_input1" class="weui-input" placeholder="填写用户名">
        </div>
    </label>
    <label for="js_input2" class="weui-cell weui-cell_active">
        <div class="weui-cell__hd"><span class="weui-label">密码</span></div>
        <div class="weui-cell__bd">
            <input name="password" id="js_input2" type="password" class="weui-input" placeholder="填写密码">
        </div>
    </label>
    <p style="color: red">
        <%
            if(request.getAttribute("message")!=null){
                out.println(request.getAttribute("message"));
            }
        %>
    </p>
    <input role="button" class="weui-btn weui-btn_primary" wah-hotarea="click" type="submit" value="确定">
</form>
</body>
</html>

修改Web.xml文件，添加servlet标签

<servlet>
    <servlet-name>login</servlet-name>
    <servlet-class>ruanko.newspublish.action.login.login</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>login</servlet-name>
    <url-pattern>/login</url-pattern>
</servlet-mapping>
<welcome-file-list>
    <welcome-file>login.jsp</welcome-file>
</welcome-file-list>

创建处理登入的DAO层代码

package ruanko.newspublish.dao;

import ruanko.newspublish.entity.Article;
import ruanko.newspublish.entity.Users;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class UsersDao extends BaseDao{
    public void register(Users users){
        String sql = "INSERT INTO users(username, password) VALUES('"+
                users.getUsername() +
                "','"+
                users.getPassword() +
                "')";
        System.out.println("SQL ={"+sql+"}");
        executeUpdate(sql);
    }

    public Users login(String username){
        String sql = "SELECT * FROM users WHERE username= '" + username+"';";
        System.out.println("SQL = {"+sql+"}");
        Connection connection = getConnection();
        Statement statement;
        try {
            statement = connection.createStatement();
            ResultSet resultSet = statement.executeQuery(sql);
            if (resultSet.next()) {
                Users users1 = new Users();
                users1.setUid(resultSet.getInt("uid"));
                users1.setUsername(resultSet.getString("username"));
                users1.setPassword(resultSet.getString("password"));
                closeAll(connection, statement, resultSet);
                return users1;
            }
        } catch (SQLException e) {
            e.printStackTrace();
            System.out.println("[mysql]查询用户名或密码错误");
        }
        return null;
    }

    public void updatePassword(Users users){
        String sql = "UPDATE users SET password = '"+ users.getPassword()+"' WHERE username = '" +
                users.getUsername() + "';";
        System.out.println("SQL ={"+sql+"}");
        executeUpdate(sql);
    }
}

创建处理登入的Servive层代码

package ruanko.newspublish.biz;

import ruanko.newspublish.dao.UsersDao;
import ruanko.newspublish.entity.Users;

public class UsersBiz {

    private UsersDao usersDao;

    public UsersBiz(){
        this.usersDao = new UsersDao();
    }

    public void register(Users users){
        usersDao.register(users);
    }

    public Users login(String username){
        return usersDao.login(username);
    }

    public void updatePassword(Users users){
        usersDao.updatePassword(users);
    }
}

创建处理登入操作的Servlet代码

package ruanko.newspublish.action.login;

import ruanko.newspublish.biz.UsersBiz;
import ruanko.newspublish.entity.Users;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Objects;

public class login extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        Users users = new Users();
        users.setUsername(request.getParameter("username"));
        String password = request.getParameter("password");
//        System.out.println(password);
        String hashPassword = md5(password);
//        System.out.println("MD5 = "+hashPassword);
        users.setPassword(hashPassword);

        UsersBiz usersBiz = new UsersBiz();
        if (usersBiz.login(users.getUsername())!=null){
            System.out.println("MysqlPasswordMd5 = "+usersBiz.login(users.getUsername()).getPassword());
            if (Objects.equals(usersBiz.login(users.getUsername()).getPassword(), hashPassword)){
                System.out.println("登入成功,跳转页面至 index.jsp");
                request.getRequestDispatcher("index.jsp").forward(request,response);
            }
        }else {
            System.out.println("登入失败，返回login.jsp");
            request.setAttribute("message","登入失败，请检查用户名和密码是否正确!");
            request.getRequestDispatcher("login.jsp").forward(request,response);
        }


    }
    public static String md5(String str){
        MessageDigest messageDigest = null;
        try {
            messageDigest = MessageDigest.getInstance("MD5"); //生成md5计算摘要
            messageDigest.update(str.getBytes()); //计算md5
            return new BigInteger(1,messageDigest.digest()).toString(16);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return null;
    }
}