Book類

package?com.library;

public?class?Book?{
	
	private?int?num;
	private?String?name;
	
		
	public?Book(int?num,?String?name)?{
		this.num?=?num;
		this.name?=?name;
	}

	public?int?getNum()?{
		return?num;
	}

	public?String?getName()?{
		return?name;
	}

}

自定義異常

package?com.library;

public?class?BookIsNotExistException?extends?Exception?{
	//自定義異常，圖書不存在
	
	public?BookIsNotExistException()
	{
		System.out.println("圖書不存在，請重新輸入！");
	}

}

搜尋圖書類

package?com.library;

import?java.util.Scanner;
import?java.util.InputMismatchException;

public?class?SearchBook?{

	private?Scanner?input?=?new?Scanner(System.in);
	?
	?//運行
????public?void??Run()
????{
????	Search();
????}
????
????//搜索圖書
????private?void?Search()
????{
???????while(true)
	?{
????	???int?choice=0;
		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");
		try?{
			choice?=?input.nextInt();
		}?catch?(InputMismatchException?e)?{
			//?輸入有誤，重新輸入
			System.out.println("命令輸入錯誤，請根據(jù)提示輸入數(shù)字命令！");
			input.next();
			continue;
		}
		
		switch(choice)
		{
		//按照名稱查找圖書
		case?1:
			System.out.println("輸入圖書名稱：");
????????????String?searchStr?=?input.next();????
			try?{	??
????????????????Book?book?=?searchByName(searchStr);
????????????????ShowBookInfo(book);
????????????????break;
			}?catch?(BookIsNotExistException?e)?{
				//?圖書不存在
				continue;
			}
			
		//按照序號查找圖書
		case?2:
			System.out.println("輸入圖書編號：");
			int?SearchNum?=?input.nextInt();
			try?{
				Book?book?=?searchByNum(SearchNum);
				ShowBookInfo(book);
				break;
			}?catch?(Exception?e)?{
				//?圖書不存在
				continue;
			}
			default:?
				System.out.println("命令輸入錯誤，請根據(jù)提示輸入數(shù)字命令！");
				break;
		}
	}
??}

//通過名字搜索圖書,拋出異常
??private?Book?searchByName(String?name)?throws?BookIsNotExistException?{
?????for?(Book?book?:?initialize.books)?{
????????if?(book.getName().equals(name))?{
????????????return?book;
????????}
????}
????throw?new?BookIsNotExistException();
??}
??
//通過編號搜索圖書,拋出異常
??private?Book?searchByNum(int?num)?throws?BookIsNotExistException?{
?????for?(Book?book?:?initialize.books)?{
????????if?(book.getNum()==num)?{
????????????return?book;
????????}
????????if?(num?>?initialize.books.length?||?num?<?1)?{
????????????throw?new?BookIsNotExistException();
????????}
????}
????return?null;
??}
??
??//顯示搜索到的圖書信息
??private?void?ShowBookInfo(Book?book)
??{
	??System.out.println("編號："?+?book.getNum()?+?"\t書名："?+?book.getName());
??}
}

實現(xiàn)類

package?com.library;

public?class?initialize?{
	
	static??Book[]?books?=?{new?Book(1,?"數(shù)據(jù)結(jié)構(gòu)"),?new?Book(2,?"離散數(shù)學(xué)"),new?Book(3,?"計算機網(wǎng)絡(luò)"),new?Book(4,?"高等數(shù)學(xué)")};
	public?static?void?main(String[]?args)?{

???????SearchBook?s?=?new?SearchBook();
???????s.Run();
??
??}
}