求助：我這個程序的按照名稱查找拋出不了異常。

package?com.imooc.exception_test;

import?java.util.Scanner;

public?class?Book?{

	public?static?void?main(String[]?args)?{
		//?用字符串?dāng)?shù)組保存書籍信息
		String[]?book?=?{?"數(shù)據(jù)結(jié)構(gòu)",?"Java實戰(zhàn)開發(fā)",?"html5",?"javascript",?"高等數(shù)學(xué)"?};
		Book?myBook?=?new?Book();
		//?處理IO
		System.out.println("按照命令查找書籍：1-按照名稱查找書籍；2-按照序號查找書籍");
		Scanner?scanner1?=?new?Scanner(System.in);

		try?{
			int?k?=?scanner1.nextInt();
			if?(k?==?1)?{
				System.out.println("請輸入書籍的名字：");
				Scanner?scanner2?=?new?Scanner(System.in);
				String?c?=?scanner2.nextLine();
				myBook.findByname(c,?book);
			}
			if?(k?==?2)?{
				System.out.println("請輸入書籍的序號");
				Scanner?scanner3?=?new?Scanner(System.in);
				int?c?=?scanner3.nextInt();
				myBook.findByIndex(c,?book);
			}
		}?catch?(Exception?e)?{
			//?TODO:?handle?exception
			System.out.println("命令輸入錯誤，請按照提示輸入數(shù)字命令");
		}

	}

	//?按名查找，拋出“書名不存在異?！?	public??void?findByname(String?input,?String?book[])?{
		try?{
			for?(int?i?=?0;?i?<?book.length;?i++)?{
				if?(book[i]?==?input)?{
					System.out.println("book:"?+?book[i].toString());
				}
			}
		}?catch?(Exception?e)?{
			//?TODO:?handle?exception
			e.printStackTrace();
			System.out.println("書名不存在異常");
		}
	}

	//?按序號查找，拋出“序號不存在異?！?	public??void?findByIndex(int?index,?String?book[])?{
		try?{
			System.out.println("book:"?+?book[index].toString());
		}?catch?(Exception?e)?{
			//?TODO:?handle?exception
			e.printStackTrace();
			System.out.println("這本書的序號不存在異常！");
		}
	}
}