交作業了?。。。。。?/h1>

import?java.util.*;
public?class?Library?{
????/*
?????*?totalBooks??存儲圖書的數組
?????*?scan?初始化輸入類對象
?????*/
	String[]??totalBooks?=?{"高等數學","計算機英語","JAVA編程","PHP面向對象","C++經典實例","高性能MySQL","JavaScript前端開發語言","jQuery高級教程"};
	Scanner?scan?=?new?Scanner(System.in);
	
	/*
	?*?bookname?輸入圖書?名稱
	?*?把數組轉換成字符串?用indexOf()方法?查找返回?索引?如果不存在返回?int?-1;
	?*?如果查找不到圖書?則拋出圖書不存在異常?接著調用welcome方法?重新輸入
	?*/
	
	public?void?bookName(){
		String?bookname?=?scan.next();
????????String?books?=?Arrays.toString(totalBooks);
????????try?{
????????	if(books.indexOf(bookname)?!=?-1){
????????????	System.out.println("book:"+?bookname);
????????????}else{
????????????	throw?new?Exception("圖書不存在");
????????????}
		}?catch?(Exception?e)?{
			System.out.println("圖書不存在?。?！");
			this.welcome();
		}
?????
	}
	
	/*
	?*?bookNum?輸入圖書序號
	?*?判斷序號如果小于1?或者?大于總圖書的數組長度?則拋出異常;
	?*?如果查找不到圖書?則拋出圖書不存在異常?接著調用welcome方法?重新輸入
	?*/
	
	public?void?bookNum(){
		int?booknum?=?scan.nextInt();
????????try?{
????????	if(booknum?<?1?||?booknum?>?totalBooks.length){
????????????	throw?new?Exception();
????????????}else{
????????????	System.out.println("book:"+totalBooks[booknum-1]);
????????????}
		}?catch?(Exception?e)?{
			System.out.println("圖書不存在?。?！");
			this.welcome();
		}
	}
	
	
	/*
	?*?input?輸入
	?*?輸入1?則按圖書名稱找書
	?*?輸入2?則按圖書序號找書
	?*?否則拋出異常???調用自身方法?重新輸入
	?*/
	
	public?void?welcome(){
		System.out.println("輸入命令：1-按照名稱查找圖書；2-按照序號查找圖書");
????????String?input?=?scan.next();
????????try?{
????????	?if?(input.equals("1")){
?????????????	System.out.println("請輸入圖書名稱：");
?????????????	this.bookName();
?????????????}
????????	?else?if?(input.equals("2"))?{
?????			System.out.println("請輸入圖書序號：");
?????			this.bookNum();
?????		}else{
?????			throw?new?Exception();
?????		}
		}?catch?(Exception?e)?{
		//	e.printStackTrace();
			System.out.println("命令輸入錯誤！請根據提示輸入數字命令！");???//捕獲異常輸出提示
			this.welcome();???//調用方法重新輸入
		}?finally?{
			scan.close();
		}
	}
	public?static?void?main(String[]?args)?{		
????????Library?lib?=?new?Library();
????????lib.welcome();???????
	}

}