package com.exception.project;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.Scanner;

public class BookUtil {

//實例化一個List對象

List<Book> bookList = new ArrayList<Book>();

//查詢方法

public void fun() {

BookUtil bu = new BookUtil();?

System.out.println("輸入命令：1-按名稱查找圖書；2-按序號查找圖書");

// List<Book> list = new ArrayList<Book>();

//輸出

Scanner scan = new Scanner(System.in);

try {

//輸入一個數(shù)

int a = scan.nextInt();

boolean flag = false;

//判斷是否為1 ，如果為1就進入按名稱查找，如果為2就進入按序號查找 ，兩者都不是就輸出查詢不到結(jié)果

if(a == 1) {

System.out.println("輸入圖書名稱：");

String name = scan.next();

for (Book book : bookList) {

if(name.equals(book.getName())) {

System.out.println(book.toString());

flag = true;

break;

}

if(flag == false) {

System.out.println("圖書名稱："+name+"沒存在！");

fun();

}

}

}else if(a == 2) {

System.out.println("輸入圖書序號：");

int id = scan.nextInt();

for (Book book : bookList) {

if(id == book.getId()) {

System.out.println(book.toString());

flag = true;

break;

}

if(flag == false) {

System.out.println("圖書名稱："+id+"沒存在！");

fun();

}

}

}else {

System.out.println("輸入數(shù)據(jù)不合格！");

fun();

}

}catch(Exception e) {

//設(shè)置異常提示信息

System.err.println("命令輸入錯誤！請根據(jù)提示輸入命令");

//如果出現(xiàn)異常就回調(diào)

fun();

}

}

//添加方法

public List<Book> addIdName() {

//創(chuàng)建一個book對象，并把book對象添加到list集合中

Book book1 = new Book(1,"高數(shù)");;

bookList.add(book1);

//創(chuàng)建一個book對象，并把book對象添加到list集合中

Book book2 = new Book(2,"java程序設(shè)計");

bookList.add(book2);

//創(chuàng)建一個book對象，并把book對象添加到list集合中

Book book3 = new Book(3,"數(shù)據(jù)庫結(jié)構(gòu)");

bookList.add(book3);

//創(chuàng)建一個book對象，并把book對象添加到list集合中

Book book4 = new Book(4,"軟件工程");

bookList.add(book4);

//返回 list

return bookList;

}

}

package com.exception.project;

import java.util.Objects;

public class Book {

private int id;

private String name;

public Book() {

}

public Book(int id, String name) {

this.id = id;

this.name = name;

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

@Override

public String toString() {

return "Book : name=" + name + "";

}

@Override

? ? public boolean equals(Object o) {

? ? ? ? if (this == o) return true;

? ? ? ? if (o == null || getClass() != o.getClass()) return false;

? ? ? ? Book book = (Book) o;

? ? ? ? return Objects.equals(name, book.name) &&

? ? ? ? ? ? ? ? Objects.equals(id, book.id);

? ? }

}

package com.exception.project;

import java.util.ArrayList;

import java.util.List;

public class test {

public static void main(String[] args) {

//實例化 BookUtil

BookUtil bu = new BookUtil();

bu.addIdName();

bu.fun();

}

}