登录注册java版:结合mysql数据库

package com.shujia.day18.logindemo;

import com.shujia.day18.utils.MysqlTool;

import java.io.*;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Properties;
import java.util.Scanner;

/*
    登录注册java版:结合mysql数据库

 */
public class IOTest3 {
    //TODO: 自己完善注册和修改的功能
    private static Scanner sc = new Scanner(System.in);


    public static void init() {
        System.out.println("=============== ^_^ 欢迎进入魏一民婚恋介绍网站 ^_^ ==================");

        System.out.println("1.登录  2.注册  3.修改  4.注销");
        System.out.print("请输入您的操作编号:");
        int choice = sc.nextInt();
        switch (choice) {
            case 1:
                login();
                break;
            case 2:
                regeist();
                break;
            case 3:
                update();
                break;
            default:
                System.out.println("您的输入有误!");
                break;
        }
    }

    public static void update() {
        //查询所有的用户
        ArrayList<User> allUsers = getAllUsers();

        System.out.println("请输入您需要修改的用户名:");
        String name = sc.next();

        //查询用户是否存在
        User user = getUserByName(name);
        if(user!=null){
            for(int i=0;i<allUsers.size();i++){
                User u = allUsers.get(i);
                if(u.getName().equals(name)){
                    allUsers.remove(u);
                }
            }

            System.out.println("请选择您要修改的内容:1.姓名   2.密码");
            int choice = sc.nextInt();
            switch (choice){
                case 1:
                    System.out.println("请输入新名称:");
                    String newName = sc.next();
                    user.setName(newName);
                    break;
                case 2:
                    System.out.println("请输入新密码:");
                    String newPwd = sc.next();
                    user.setPassword(newPwd);
                    break;
                default:
                    System.out.println("无效输入!");
                    break;
            }
        }else {
            return;
        }

        //将修改后用户添加到集合中
        allUsers.add(user);

        BufferedWriter bw= null;
        try {
            //创建字符缓冲输出流
            bw = new BufferedWriter(new FileWriter("src/com/shujia/day17/data/users.txt"));
            for (User allUser : allUsers) {
                bw.write(allUser.getName()+","+allUser.getPassword());
                bw.newLine();
                bw.flush();
            }

            System.out.println("用户修改成功!");

        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if(bw!=null){
                try {
                    bw.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }



    }

    public static User getUserByName(String name) {
        BufferedReader br = null;
        boolean flag = true;

        User user = null;

        try {
            //创建字符缓冲输入流对象
            //public FileReader(File file)
            File file = new File("src/com/shujia/day17/data/users.txt");
            //判断用户文件中是否用用户
            if (file.length() > 0) {
                br = new BufferedReader(new FileReader(file));
                String line = null;
                while ((line = br.readLine()) != null) {
                    //魏一民,123456
                    String name1 = line.split(",")[0];
                    String password1 = line.split(",")[1];
                    //判断用户是否与登录的用户一样
                    if (name1.equals(name)) {
                        flag = false;
                        user = new User(name1,password1);
                        break;
                    }
                }

                if (flag) {
                    System.out.println("该用户未进行注册!");
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        return user;
    }

    public static void regeist() {
        System.out.println("----------------- 欢迎注册魏一民婚恋介绍网站 --------------------");
        ArrayList<User> allUsers = getAllUsers();
        String password = null;
        BufferedWriter bw = null;

        System.out.print("请输入您的用户名:");
        String name = sc.next();
        for (User user : allUsers) {
            if (user.getName().equals(name)) {
                System.out.println("该用户名已被使用!");
                return; // 方法已经结束了
            }
        }

        System.out.println("请设置账户密码:");
        password = sc.next();

        try {
            //将用户名和密码写到文件中
            bw = new BufferedWriter(new FileWriter("src/com/shujia/day17/data/users.txt", true));

            bw.newLine();
            bw.write(name + "," + password);
            bw.flush();
            System.out.println("用户注册成功!");

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (bw != null) {
                try {
                    bw.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    public static ArrayList<User> getAllUsers() {
        BufferedReader br = null;
        //创建一个ArrList集合,用户存储读取到用户
        ArrayList<User> users = new ArrayList<>(); // 新创建的集合中元素个数是0
        try {
            //创建字符缓冲输入流对象
            //public FileReader(File file)
            File file = new File("src/com/shujia/day17/data/users.txt");
            //判断用户文件中是否用用户
            if (file.length() > 0) {
                br = new BufferedReader(new FileReader(file));
                String line = null;
                while ((line = br.readLine()) != null) {
                    //魏一民,123456
                    String name1 = line.split(",")[0];
                    String password1 = line.split(",")[1];
                    //判断用户是否与登录的用户一样
                    users.add(new User(name1, password1));
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return users;
    }


    public static void login() {
        try {
            Scanner sc2 = new Scanner(System.in);
            System.out.print("请输入您的用户名:");
            String name = sc2.nextLine();
            System.out.print("请输入您的密码:");
            String password = sc2.nextLine();

            //去数据库中查询用户数据,若查到结果集是有数据的
//        String url = "jdbc:mysql://192.168.136.100:3306/bigdata31?useUnicode=true&characterEncoding=utf-8&useSSL=false";
//        String username2 = "root";
//        String password2 = "123456";
            //读取配置文件,获取键对应的值
            //创建Properties类对象
            Properties properties = new Properties();
            //指定要读取的配置文件
            properties.load(new BufferedReader(new FileReader("src/com/shujia/day18/confs/info.properties")));
            //getProperty()  通过键获取对应的值
            String url = properties.getProperty("url");
            String username2 = properties.getProperty("user");
            String password2 = properties.getProperty("password");
            Connection conn = MysqlTool.getConnection(url, username2, password2);
            System.out.println("成功获取与数据库的链接对象:"+conn);

            /**
             *  普通的Statement数据库操作对象,会存在sql注入的问题
             *  原因是因为先进行sql拼接的,然后再做解析,会将sql中一些本来应该是值的内容解析成sql中的语法了
             *
             */
//            Statement state = conn.createStatement();
//            //select * from users where username='小虎' and password='123456';
//            //select * from users where username='小虎' and password='123 345'
//            //select * from users where username='小虎' and password='qwew' or '1'='1'
//            String sql = "select * from users where username='" + name + "' and password='" + password + "'";
//            System.out.println(sql);
//            ResultSet resultSet = state.executeQuery(sql);


            /**
             *  要想解决sql注入的问题,就不能使用普通的Statement数据库操作对象,改用预编译对象
             */
            PreparedStatement prepareStatement = conn.prepareStatement("select * from users where username=? and password=?");
            //传?的值
            prepareStatement.setString(1,name);
            prepareStatement.setString(2,password);
            //执行sql语句
            ResultSet resultSet = prepareStatement.executeQuery();

            if(resultSet.next()){
                System.out.println("登录成功!!");
            }else {
                System.out.println("登录失败!!");
            }

        }catch (Exception e){
            e.printStackTrace();
        }
    }


    public static void main(String[] args) {
        init();

    }
}
posted @ 2024-08-21 21:33  ていせい  阅读(3)  评论(0编辑  收藏  举报