package?library1;

public?class?Book?{
	int?num;
	String?name;
	public?Book(int?num,String?name){
		this.num=num;
		this.name=name;
	}
	?Book[]books={new?Book(1,"數(shù)據(jù)結(jié)構(gòu)"),
			new?Book(2,"線性數(shù)學(xué)"),new?Book(3,"高等數(shù)學(xué)")};

}

package?library1;

import?java.util.Scanner;

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(hào)查找圖書");
		try{
		Scanner?sc=new?Scanner(System.in);
		int?a=sc.nextInt();
		if(a==1){
			library1();
		}else?if(a==2){
			library2();
		}else{
			System.out.println("您輸入的數(shù)據(jù)有誤，請(qǐng)重新輸入(1或2)");
		}
		}catch(Exception?e){
			System.out.println("命令輸入有誤，請(qǐng)?zhí)崾据斎朊?);
			library();//重新調(diào)用方法，實(shí)現(xiàn)數(shù)據(jù)回滾
		}
	}
	//按照?qǐng)D書名稱查找
	public?void?library1(){
		System.out.println("請(qǐng)輸入圖書名稱:");
		try{
		Scanner?sc=new?Scanner(System.in);
		String?b=sc.next();
		for(Book?book:books){
			if(book.name.equals(b)){
				System.out.println("books:"+book.name);
				break;
			}
		}
		}catch(Exception?e){
			System.out.println("圖書不存在！");
			library1();
		}
	}
	//按照?qǐng)D書序號(hào)查找
	public?void?library2(){
		System.out.println("請(qǐng)輸入圖書名稱:");
		try{
		Scanner?sc=new?Scanner(System.in);
		int?c=sc.nextInt();
		for(Book?book:books){
			if(book.num==c){
				System.out.println("books:"+book.name);
				break;
			}
		}
		}catch(Exception?e){
			System.out.println("圖書不存在！");
			library2();
		}
	}
	

}

package?library1;

public?class?Initail?{

	public?static?void?main(String[]?args)?{
		//?TODO?自動(dòng)生成的方法存根
		System.out.println("歡迎登陸借書系統(tǒng)");
		Library?lb=new?Library();
		lb.library();

	}

}