package?library;
import?java.util.Scanner;//掃描
public?class?Library?{
?public?void?library(){
	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");//打印輸出
	try{//try{}catch(){}語句塊的應用
		Scanner?input=new?Scanner(System.in);
	int?a=input.nextInt();
	?if(a==1){
		library1();//輸入1，調用library1方法
	?}else?if(a==2){
		?library2();//輸入2調用library2方法
	?}else?{
		?System.out.println("命令輸入錯誤，請根據提示輸入數字命令！(1或2)");
			library();//輸入其它整數則提示重新輸入
	?}
	}catch(Exception?e){//異常捕獲
		System.out.println("命令輸入錯誤，請根據提示輸入數字命令！");
		library();//異常處理，回滾重新輸入
	}
	}
?public?void?library1(){
	?System.out.println("輸入圖書名稱：");
	?try{
		?Scanner?input=new?Scanner(System.in);
	?String?b=input.next();//掃描?輸入字符串（輸入圖書名稱）
	?for(int?i=0;;i++){//用for循環遍歷?搜索系統中是否有要借的圖書
		?if((Books.books[i].name).equals(b)){
			?System.out.println("book:"+b);
			?break;//有則結束循環，沒有則拋出一個異常
		?}
		
	?}
		?
	?}catch(Exception?e){
		?System.out.println("圖書不存在！");//異常處理方式?重新輸入圖書
			library1();
	?}
	?
?}
?public?void?library2(){//參照library1
	?System.out.println("輸入圖書序號:");
	?try{
		?Scanner?input=new?Scanner(System.in);
	?int?b=input.nextInt();
	?for(int?i=0;;i++){
		?if(Books.books[i].num==b){
			?System.out.println("book:"+Books.books[i].name);
			?break;
		?}
		
	?}
		?
	?}catch(Exception?e){
		?System.out.println("圖書不存在！");
			library2();
	?}
?}
}

package?library;

public?class?Books?{//數據模型
	int?num;
	String?name;
	public?Books(int?num,String?name){//構造函數??存儲書本序號，及名字
		this.num=num;
		this.name=name;
	}
public?static?Books[]books={new?Books(1,"數據結構"),new?Books(2,"高數"),new?Books(3,"線性代數")
		
};//數組信息

}

package?library;//測試類

public?class?Initail?{

	/**
	?*?@param?args?
	?*/
	public?static?void?main(String[]?args){
		//?TODO?Auto-generated?method?stub
		System.out.println("歡迎登錄借書系統");
		Library?input=new?Library();//建立對象
		input.library();
	}

}