Java入门第三季第一章异常与异常处理---图书管理系统

//命令错误异常
package imooc;

public class ErroCommandExp extends Exception {
    public ErroCommandExp(){

    }
    public ErroCommandExp(String message){
        super(message);
    }
}

//图书不存在异常
package imooc;

import java.util.InputMismatchException;

public class NonBookExp extends InputMismatchException {
    public NonBookExp(){

    }
    public NonBookExp(String message){
        super(message);
    }
}

//主函数
package imooc;

import java.util.InputMismatchException;
//import java.util.NoSuchElementException;
import java.util.Scanner;;

public class Initial {
    public int command() throws ErroCommandExp{
        Scanner input = new Scanner(System.in);
        int i;
        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");
        try{
            i = input.nextInt();      //输入不匹配异常
        }catch(InputMismatchException e){
            throw new ErroCommandExp("命令错误异常");

        }       
        if( (i != 1) && (i != 2) ){    //输入命令非1、2异常
            throw new ErroCommandExp("命令错误异常");
        }
        return i;   
    }
    public void searchName(String[] bookStore) throws NonBookExp{
        Scanner input = new Scanner(System.in);
        int k = 0;
        System.out.println("请输入图书名称：");
        String bookName = input.nextLine();
        for( ;k < bookStore.length; k++){   //输入的图书名称一个个做对比
            if(bookStore[k].equals(bookName)){
                System.out.println("book:" + bookName);
                break;                      //如果找到则输出图书的名称并 跳出for循环
            }                   
        }       
        if(k == bookStore.length){          //对比完仍没找到这抛出图书不存在异常
            throw new NonBookExp("图书不存在异常");
        }
    }
    public void searchId(String[] bookStore) throws NonBookExp{
        Scanner input = new Scanner(System.in);
        System.out.println("请输入图书序号：");     
        int bookNum = input.nextInt();
        if( (bookNum >= bookStore.length) || (bookNum < 0) ){  //输入图书的编号小于零或者大于图书的数量则抛出图书不存在异常
            throw new NonBookExp("图书不存在异常");            
        }else{
            System.out.println("book:" + bookStore[bookNum]);
        }       
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        String[] bookStore = {"数据结构", "高数", "Java核心技术卷一", "Java核心技术卷二"};
        Initial book = new Initial();

        while(true){
            int n = 0;
            try{
                n = book.command();
            }catch(ErroCommandExp e){
                System.out.println("命令错误，请从新输入！！！");
            }

            switch(n){
            case 1: try{
                        book.searchName(bookStore);
                    }catch(NonBookExp e){
                        System.out.println("图书不存在！！！");
                    }
                    break;
            case 2: try{
                        book.searchId(bookStore);
                    }catch(NonBookExp e){
                        System.out.println("图书不存在！！！");
                    }
                    break;
            }
        }

    }
}