Java-图书管理系统

package com.tony;
/*
 * 图书租赁系统
 */
public class Book {
	public String bookName;
	public int bookId;
	public Book(String bookName, int bookId){
		this.bookName = bookName;
		this.bookId = bookId;
	} 
}

package com.tony;
/*
 * 自定义异常类
 */
public class MyException extends Exception{
	//有参构造方法
	public MyException(String message) {
		super(message);
	};
}

package com.tony;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
/*
 * 主程序
 */
public class BorrowBook {
	
	Book book [] = {new Book("高等数学", 1), new Book("大学英语", 2), new Book("Android", 3), new Book("会计基础", 4)};
	public List<Book> listBooks;
	//无参构造方法
	public BorrowBook() {
		this.listBooks = new ArrayList<Book>();
	}
	public void addBook(){
		listBooks.addAll(Arrays.asList(book));
	} 
	public void systemOut() {
		System.out.println("*******欢迎使用借书系统*******");
		System.out.println("*-*-*-*图书一览表：*-*-*-*");
		System.out.println("     书名" + "\t\t" + "序号");
		for(Book book:listBooks) {
			System.out.println(book.bookName + "\t\t " +book.bookId);
		}
	}
	private Scanner scanner = new Scanner(System.in);
	public static void main(String[] args) {
		BorrowBook borrowBook = new BorrowBook();
		borrowBook.addBook();
		borrowBook.systemOut();
		
		while(true) {
			System.out.println("输入命令：1-按照名称查找图书;2-按照序号查找图书");
			switch (borrowBook.scanf()) {
			case 1://根据用户不同的输入内容执行
				try {
					System.out.println("书籍：" + borrowBook.findByName());
					break;
				} catch (Exception e) {
					System.out.println(e.getMessage());
					continue;
				}
			case 2:
				try {
					System.out.println("书籍：" + borrowBook.findById());	
					break;
				} catch (Exception e) {
					System.out.println(e.getMessage());
					continue;
				}
				default:
					System.out.println("命令错误，请重试.");
					continue;
			}
			break;
		}
		borrowBook.scanner.close();
	}
	public String findByName() throws MyException{
		System.out.println("*****请输入书籍的名称-->");
		String name = scanner.next();
		for (Book books : book) {
			if (name.equals(books.bookName)) {
				return books.bookName + "\t序号：" +books.bookId;
			}
		}
		throw new MyException("名称错误，请重试.");
	}
	public String findById() throws MyException {
		System.out.println("*****请输入书籍的序号-->");
		int in = scanner.nextInt();
		for (int i = 0; i < book.length; i++) {
			if (in == (i + 1)) {
				return book[i].bookName + "\t序号：" + (i+1);
			}
		}
		throw new MyException("下标越界，请重试.");
	}
	public int scanf() {
		try {
			int in = scanner.nextInt();
			return in;
		} catch(Exception e) {
			scanner = new Scanner(System.in);
			return -1;
		}
	}
}