到 错误命令异常就不能正常循环这是为什么

Question

import java.util.*;public class CheckBook{  public static final String[] book = {"春天日记","高等数学","计算机概述","网络设计","论语","青春的躁动","大学英语"};  public static boolean right = true;  Scanner scanner = new Scanner(System.in);  public static void main(String[] args){    CheckBook checkBook = new CheckBook();    while(right){      try{        checkBook.test1();      }catch(Exce e){        e.printStackTrace();      }   }  }  public void test1()throws Exce {      System.out.println("请输入您要查询的id:");      if(scanner.hasNextInt()){        int number = scanner.nextInt();        if(number>book.length || number<0){          throw new Exce("序号不存在！");        }else{          System.out.println("请输入书籍名称：");                   String bookName = scanner.next();          if(bookName.equals(book[number-1])){            System.out.println("图书馆中有此书，书的序号为："+number);            right = false;          }else{            throw new Exce("图书不存在！");          }        }      }else{        throw new Exce ("错误命令异常！");      }    }}