图书管理系统java

好的，你需要一个图书管理系统的Java代码是吗？那么我们可以一步一步来实现。

首先，你需要定义一个Book类，来表示图书的属性：

public class Book {
    private String title;
    private String author;
    private String ISBN;
    private int quantity;
    
    public Book(String title, String author, String ISBN, int quantity) {
        this.title = title;
        this.author = author;
        this.ISBN = ISBN;
        this.quantity = quantity;
    }
    
    // Getter and setter methods for all attributes
}

然后，你需要创建一个BookList类，来管理所有的图书：

import java.util.ArrayList;

public class BookList {
    private ArrayList<Book> books;
    
    public BookList() {
        books = new ArrayList<Book>();
    }
    
    public void addBook(Book book) {
        books.add(book);
    }
    
    public void removeBook(Book book) {
        books.remove(book);
    }
    
    public ArrayList<Book> searchByTitle(String title) {
        ArrayList<Book> result = new ArrayList<Book>();
        for (Book book : books) {
            if (book.getTitle().equals(title)) {
                result.add(book);
            }
        }
        return result;
    }
    
    public ArrayList<Book> searchByAuthor(String author) {
        ArrayList<Book> result = new ArrayList<Book>();
        for (Book book : books) {
            if (book.getAuthor().equals(author)) {
                result.add(book);
            }
        }
        return result;
    }
    
    public ArrayList<Book> searchByISBN(String ISBN) {
        ArrayList<Book> result = new ArrayList<Book>();
        for (Book book : books) {
            if (book.getISBN().equals(ISBN)) {
                result.add(book);
            }
        }
        return result;
    }
    
    // Other methods to manage the book list
}

最后，你需要创建一个Main类，来运行整个程序：

import java.util.ArrayList;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        BookList bookList = new BookList();
        
        while (true) {
            System.out.println("请选择操作：");
            System.out.println("1. 添加图书");
            System.out.println("2. 删除图书");
            System.out.println("3. 按书名查找");
            System.out.println("4. 按作者查找");
            System.out.println("5. 按ISBN查找");
            System.out.println("6. 退出程序");
            
            int choice = scanner.nextInt();
            scanner.nextLine();
            
            switch (choice) {
                case 1:
                    System.out.println("请输入书名：");
                    String title = scanner.nextLine();
                    System.out.println("请输入作者：");
                    String author = scanner.nextLine();
                    System.out.println("请输入ISBN：");
                    String ISBN = scanner.nextLine();
                    System.out.println("请输入数量：");
                    int quantity = scanner.nextInt();
                    scanner.nextLine();
                    
                    Book book = new Book(title, author, ISBN, quantity);
                    bookList.addBook(book);
                    System.out.println("添加成功！");
                    break;
                case 2:
                    System.out.println("请输入ISBN：");
                    ISBN = scanner.nextLine();
                    
                    ArrayList<Book> result = bookList.searchByISBN(ISBN);
                    if (result.size() == 0) {
                        System.out.println("没有找到该图书！");
                    } else {
                        for (Book b : result) {
                            bookList.removeBook(b);
                            System.out.println("删除成功！");
                        }
                    }
                    break;
                case 3:
                    System.out.println("请输入书名：");
                    title = scanner.nextLine();
                    
                    result = bookList.searchByTitle(title);
                    if (result.size() == 0) {
                        System.out.println("没有找到该图书！");
                    } else {
                        for (Book b : result) {
                            System.out.println(b.toString());
                        }
                    }
                    break;
                case 4:
                    System.out.println("请输入作者：");
                    author = scanner.nextLine();
                    
                    result = bookList.searchByAuthor(author);
                    if (result.size() == 0) {
                        System.out.println("没有找到该图书！");
                    } else {
                        for (Book b : result) {
                            System.out.println(b.toString());
                        }
                    }
                    break;
                case 5:
                    System.out.println("请输入ISBN：");
                    ISBN = scanner.nextLine();
                    
                    result = bookList.searchByISBN(ISBN);
                    if (result.size() == 0) {
                        System.out.println("没有找到该图书！");
                    } else {
                        for (Book b : result) {
                            System.out.println(b.toString());
                        }
                    }
                    break;
                case 6:
                    System.out.println("程序已退出！");
                    return;
                default:
                    System.out.println("无效的选项！");
                    break;
            }
        }
    }
}

这就是一个简单的图书管理系统的Java代码，你可以根据需求进行修改和扩展。