作业问题，勉强算是完成，记录下。

import java.util.Scanner;

public class Library {

    public String[] books = {"数学","语文","物理","英语","化学","体育"};

    public static void main(String[] args){
        Library lb = new Library();
        lb.book();
    }
    
    /**
     * 显示图书馆的操作命令
     * 根据输入的值，执行相应的操作
     */
    public void book(){
        System.out.println("欢迎进入图书馆借书系统");
        System.out.println("1-按照名称查询图书;2-按照序号查询图书");
        try {
            @SuppressWarnings("resource")
            Scanner k = new Scanner(System.in);//扫描控制台输入的值
            int number = k.nextInt();//nextInt()方法会读取下一个int型标志的token.但是焦点不会移动到下一行，仍然处在这一行上。
            switch (number) {
            case 1:
                find1();
                break;
            case 2:
                find2();
                break;
            default:
                System.out.println("请按要求输出值");
                break;
            }
        } catch (Exception e) {
            System.out.println("请输入正确数值");
            book();
        }
    }
    
    /**
     * 图书馆书名查询
     */
    @SuppressWarnings("resource")
    public void find1(){
        System.out.println("欢迎进入图书馆书名查询系统,请输入书名：");
        try {
            Scanner k = new Scanner(System.in);
            String name = k.next();
            switch(name){
            case "数学":
                System.out.println("已查询到您所需的图书:"+name);
                break;
            case "语文":
                System.out.println("已查询到您所需的图书:"+name);
                break;
            case "物理":
                System.out.println("已查询到您所需的图书:"+name);
                break;
            case "英语":
                System.out.println("已查询到您所需的图书:"+name);
                break;
            case "化学":
                System.out.println("已查询到您所需的图书:"+name);
                break;
            case "体育":
                System.out.println("已查询到您所需的图书:"+name);
                break;
            default:
                System.out.println("非常抱歉！暂未查询出您所需的图书。");
                break;
            }
        } catch (RuntimeException e) {
            System.out.println("您输入有误，请重新输入！");
        }finally{
            System.out.println("是否继续查询(Y/N);N-返回借书系统");
            Scanner k1 = new Scanner(System.in);
            String n1 = k1.nextLine();
            if(n1.equals("Y")||n1.equals("y")){
                find1();
            }else{
                book();
            }
        }
    }
    
    /**
     * 图书馆图书序列号查询
     */
    @SuppressWarnings("resource")
    public void find2(){
        System.out.println("请输入所需查找的图书序列号：");
        try {
            Scanner k = new Scanner(System.in);
            int number = k.nextInt();
            if(number <= books.length-1){
                System.out.println("查询出的图书为："+books[number-1]);
            }else{
                System.out.println("您查找的书不存在！");
            }
        } catch (Exception e) {
            System.out.println("您输入有误！");
        }finally{
            System.out.println("是否继续查询(Y/N)");
            Scanner k2 = new Scanner(System.in);
            String n2 = k2.nextLine();
            if(n2.equals("Y")||n2.equals("y")){
                find2();
            }else{
                book();
            }
        }
    }
}