自定义异常实现登录（续上次图书管理系统改）

package library.Exception;
 
public class UserNameException extends RuntimeException{
    public UserNameException(){
        super();
    }
    public UserNameException(String s){
        super(s);
    }
}

package library.Exception;
 
public class PassWordException extends RuntimeException{
 
    public PassWordException(){
        super();
    }
    public PassWordException(String s){
        super(s);
    }
}

package library;
 
import library.Book.BookList;
import library.Exception.PassWordException;
import library.Exception.UserNameException;
import library.User.AdminUser;
import library.User.NormalUser;
import library.User.User;
 
import java.util.Scanner;
 
public class Test {
    public String userName = "admin";
    public String password = "1234";
 
 
 
    public User login() throws UserNameException,PassWordException{
        System.out.println("请输入您的姓名");
        Scanner sc = new Scanner(System.in);
        String name = sc.nextLine();
        System.out.println("请输入您的身份:1->管理员 0->普通用户");
        int choice = sc.nextInt();
        if(choice == 1){
            sc.nextLine();//吃回车
            System.out.println("输入用户名");
            String name1 = sc.nextLine();
            System.out.println("请输入密码");
            String password = sc.nextLine();
            if(!userName.equals(name1)){
                throw new UserNameException("兄弟用户名错了");
            }
            if(!this.password.equals(password)){
                throw new PassWordException("兄弟密码错了");
            }
            return new AdminUser(name);
        }else {
            return new NormalUser(name);
        }
    }
    public static void main(String[] args) {
        Test test = new Test();
        User user = null;
        BookList bookList = new BookList();
        try {
            user = test.login();
        }catch (UserNameException e){
            e.printStackTrace();
            System.out.println("用户名异常");
        }catch (PassWordException e){
            e.printStackTrace();
            System.out.println("密码异常");
        }finally {
 
        }
 
        while (true) {
            int choice = user.menu();
            user.doWork(choice,bookList);
        }
 
 
 
    }
}