Java图书查询系统实例（简化精炼版及部分更正）

1.创建书大类

public class Book {
private String name;
private int num;

public Book(String name,int num){
	this.name=name;
	this.num=num;

}
public String getName(){
	return name;
}
public void setName(String name){
	this.name=name;
}
public int getNum(){
	return num;

}
public void setNum(int num){
	this.num=num;
}
}

2.自定义异常

public  class NoExistException extends Exception{
	public NoExistException(String message){
		super(message);

	}
	public NoExistException(){

	}
}

3.主程序

import java.util.*;
public class Test2 {
	 private Scanner input = new Scanner(System.in);
	 Book[] book={
			 new Book("语文",1),
			 new Book("数学",2),
			 new Book("英语",3),
			 new Book("专业课",4)

	 };
//	 public List<Book> listbooks;
//	 public Test2() {
//         this.listbooks = new ArrayList<Book>();
//         }
//     public void listBooksAdd() {
//         listbooks.addAll(Arrays.asList(book));
//         }
	 public void printbook(){
		 System.out.println("====欢迎使用选书系统====");
		 System.out.println("=====书本信息如下：=====");
		 System.out.println("序号"+"\t"+"书名");
		 for(Book bk:book){
			 System.out.println(bk.getNum()+"\t"+bk.getName());
		 }
	 }

		public static void main(String[] args) {
			Test2 tc=new Test2();
//			tc.listBooksAdd();
			tc.printbook();

			while(true){
		    System.out.println("请选择查书方式1-通过序号2-通过书名：");
			switch(tc.back()){
			case 1:
				try{
				 System.out.println("您的书为："+tc.fbid());
				 break;
				}catch(Exception e){
					System.out.println(e.getMessage());
					continue;
				}
			case 2:
				try{
					System.out.println("您的书为："+tc.fbbn());
					break;
				}catch(Exception e){
					System.out.println(e.getMessage());
					continue;
				}
			default:
				System.out.println("输入错误！请重新输入！！！");
				continue;
			}break;
			}

}
public String fbid() throws NoExistException{
	System.out.println("请输入图书的序号：");
	int in=input.nextInt();
	for(Book bk:book){
		if(in==bk.getNum()){
			return book[in-1].getName();
		}
	}
	throw new NoExistException("序号越界请重新输入");
}
public String fbbn()throws NoExistException{
	System.out.println("请输入图书的书名：");
	String in=input.next();
	for(Book bk:book){
		if(in.equals(bk.getName())){
			return bk.getName();
		}
	}
	throw new NoExistException("此书不存在");

}
public int back(){
	int in=input.nextInt();
	return in;
}
}