数据库用户登录

小灰灰 2024-04-18 15:18 60阅读 0赞

**数据库用户登录**  
数据表  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1NDkwNjM4_size_16_color_FFFFFF_t_70]

//USER的BEAN对象类就自己建吧，对应自己的数据库来建立
        package com.server;import java.util.List;import com.pojo.Student;
    import com.pojo.Teacher;
    import com.pojo.User;
    import com.pojo.userInfo;
    import com.untils.DataBaseConnection;public class userSever {
    	public userSever() {
    		// TODO Auto-generated constructor stub
    		System.out.println(123);
    	}
    	public userInfo login(User user) {
    		System.out.println(123);
    		//SELECT * FROM user WHERE user_name = ? AND password = ?
    		List<User> users = DataBaseConnection.query("SELECT * FROM user WHERE user_name = ? AND password = ?"，User.class, user.getUserName(), user.getPassword());
    		System.out.println(4647);
    		System.out.println(users.size());
    		if (users == null || users.size() == 0) {
    			System.out.println("判定属性");
    			return null;
    		}
    		System.out.println("判定属性123");
    		User u = users.get(0);
    		userInfo ui = new userInfo(u);
    		if (u.gettId() != null) {
    			Teacher tea = DataBaseConnection.query("SELECT * FROM teacher WHERE id = ? ", Teacher.class, u.gettId()).get(0);
    			ui.setTeacher(tea);
    			ui.setState(0);
    		}
    		if (u.getsId() != null) {
    			Student stu = DataBaseConnection.query("SELECT * FROM student WHERE id = ?", Student.class, u.getsId()).get(0);
    			ui.setStudent(stu);
    			ui.setState(1);
    		}else {
    			ui.setState(2);
    		}
    		return ui;
    	}
    }

package com.system;import java.util.Scanner;import com.pojo.User;
    import com.pojo.userInfo;
    import com.server.userSever;public class StudentSystem {
    	Scanner scanner;
    	private userSever userSever;
    	private userInfo ui;
    public StudentSystem() {
    	super();
    	scanner = new Scanner(System.in);
    	userSever = new userSever();
    	ui = new userInfo();
    }public void startSystem() {
    	System.out.println("\t 欢迎来到学生选课系统 \t");
    	System.out.print(" 1.登录 : \t ");
    	System.out.print("2.注册  ： \t");
    	System.out.println("3. 退出  : ");
    	System.out.println(">..");
    	String result = scanner.nextLine();
    	switch (result) {
    	case "1":
    		login();
    		break;
    	case "2":
    		System.out.println(12345);
    		break;
    	default:
    		break;
    	}
    }public boolean login() {
    	User user = new User();
    	System.out.println("请输入用户名  ： ");
    	user.setUserName(scanner.nextLine());
    	System.out.println("请输入密码  ： ");
    	user.setPassword(scanner.nextLine());
    	this.ui = userSever.login(user);
    	System.out.println(3);
    	if (ui == null) {
    		System.out.println("登录失败，用户名和密码不匹配！！！");
    	} else {
    		switch (ui.getState()) {
    		case 0:
    			// 老师菜单
    			break;
    		case 1:
    			// 学生菜单
    			break;
    		case 2:
    			// 管理员菜单
    			break;
    		default:
    			break;
    		}
    	}
    	return true;
    }public void register() {}}

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1NDkwNjM4_size_16_color_FFFFFF_t_70]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/8a0c31129e35411e992a52c842534ac8.png