求教下大神 我如果不把 Scanner input = new Scanner(System.in);在每个方法中都重新定义一下，为什么在异常时候不会让我重新输入，就会陷入无尽循环。

package com.Project3;

import java.util.InputMismatchException;

import java.util.Scanner;

public class Test {

public void findBook(){

for(int i = 1;;){

try{

System.out.println("输入命令：1-按照书名查书；2-按照序号查书");

Scanner input = new Scanner(System.in);

int k = input.nextInt();

String name;

if(k == 1){

name = getbookname();

System.out.println("book:"+name);

break;

}

if(k==2){

name = getbooknum();

System.out.println("book:"+name);

break;

}

else {

System.out.println("输入有误");

continue;

}

}catch(InputMismatchException e){

System.out.println("命令输入错误！请根据指令输入数字命令！");

}

catch(Exception e){

System.out.println(e.getMessage());

}

continue;

}

}

public String getbookname() throws Exception{

Scanner in = new Scanner(System.in);

System.out.println("请输入图书名称：");

String name = in.next();

if(name.equals("高数")){

return name;

}else{

throw new Exception("图书不存在！");

}

}

public String getbooknum() throws Exception{

while(true){

System.out.println("请输入图书序号：");

Scanner in = new Scanner(System.in);

int num = in.nextInt();

try{

if(num == 1){

return "数据结构";

}else{

throw new Exception("图书不存在");

}

}catch(InputMismatchException e){

throw new Exception("命令输入错误！请根据指令输入数字命令");

}

}

}

public static void main(String[] args) {

Test c = new Test();

c.findBook();

}

}