JAVA入门第三季，借书系统

package com.imooc;

import java.util.InputMismatchException;
import java.util.Scanner;

public class RentBook {

    public static void main(String[] args) {
        String[] books = {"高数","离散数学","数据结构","算法导论","数据库","JAVA语言"};
        for(int i=0;;i++){
        System.out.println("请选择查询方式：按照图书名称查询输入1，按照图书序号查询输入2");
        Scanner scan = new Scanner(System.in);
        int input = 0;
        try{
         input = scan.nextInt();
        }catch(InputMismatchException e){
//          e.printStackTrace();
            System.out.println("输入命令错误，请输入数字1或2");
        }
        if(input==1){
            System.out.println("请输入图书名称：");
            try{
                String input1 = scan.next();
                switch(input1){
                case "高数":
                    System.out.println("book:"+books[0]);
                    break;
                case "离散数学":
                    System.out.println("book:"+books[1]);
                    break;
                case "数据结构":
                    System.out.println("book:"+books[2]);
                    break;
                case "算法导论":
                    System.out.println("book:"+books[3]);
                    break;
                case "数据库":
                    System.out.println("book:"+books[4]);
                    break;
                case "JAVA语言":
                    System.out.println("book:"+books[5]);
                    break;  
                default:
                    System.out.println("图书不存在，请选择其他书籍");
                    break;
                }
            }catch(InputMismatchException e){
                System.out.println("输入命令错误，请输入图书名称");
            }
        }else{
            System.out.println("请输入图书序号：");
            try{
                int input2 = scan.nextInt();
                switch(input2){
                case 1:
                    System.out.println("book:"+books[0]);
                    break;
                case 2:
                    System.out.println("book:"+books[1]);
                    break;
                case 3:
                    System.out.println("book:"+books[2]);
                    break;
                case 4:
                    System.out.println("book:"+books[3]);
                    break;
                case 5:
                    System.out.println("book:"+books[4]);
                    break;
                case 6:
                    System.out.println("book:"+books[5]);
                    break;  
                default:
                    System.out.println("图书不存在，请选择其他书籍");
                    break;
                }
            }catch(InputMismatchException e){
                System.out.println("输入命令错误，请输入图书序号");
            }   
        }
    }
    }
}

结果显示：