图书管理系统设计JAVA代码 1)借书。图书借阅信息:借阅人、借阅人所在单位、借书证号、所借书名、借阅日期、归还日期、逾期罚款等。借阅期限为一个月，逾期1天，罚款1角。2)还书。 3)图书维护:删除图书，增加图书等。图书基本信息:图书编号、书名、作者(要考虑多个作者情况)、出版社、出版日期、定价、馆藏数、借阅数等 4)读者维护:包括新增读者、更改读者信息、查找读者、读者信息删除、读者信息输出。 5)要求利用菜单的形式进行管理。 提示:建议对读者和图书都使用类进行管理。需要创建类 1.读者类 包括读者编号、读者姓名、所借图书等，实现对读者的信息的描述图书类 包括图书的编号、书名、是否借出等，实现对图书的描述。 2.读者库类 读者信息保存在一个文本文件中(以下假定为readertxt)，实现利用文本文件建立读者的个人资料、按编号查找、输出或删除所有读者信息 3,图书库类 图书信息保存在一个文本文件中(以下假定为booktxt)，实现对图书的维护、查找和删除等。

以下是一个简单的图书管理系统的JAVA代码，实现了借书、还书、图书维护和读者维护等功能。其中，用到了读者类、图书类、读者库类和图书库类。

读者类：

public class Reader {
    private String id; // 读者编号
    private String name; // 读者姓名
    private List<Book> books; // 所借图书列表

    public Reader(String id, String name) {
        this.id = id;
        this.name = name;
        books = new ArrayList<>();
    }

    public String getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public List<Book> getBooks() {
        return books;
    }

    public void borrowBook(Book book) {
        books.add(book);
    }

    public void returnBook(Book book) {
        books.remove(book);
    }
}

图书类：

public class Book {
    private String id; // 图书编号
    private String name; // 书名
    private List<String> authors; // 作者列表
    private String publisher; // 出版社
    private String publishDate; // 出版日期
    private double price; // 定价
    private int total; // 馆藏数
    private int borrowed; // 借阅数

    public Book(String id, String name, List<String> authors, String publisher, String publishDate, double price, int total, int borrowed) {
        this.id = id;
        this.name = name;
        this.authors = authors;
        this.publisher = publisher;
        this.publishDate = publishDate;
        this.price = price;
        this.total = total;
        this.borrowed = borrowed;
    }

    public String getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public List<String> getAuthors() {
        return authors;
    }

    public String getPublisher() {
        return publisher;
    }

    public String getPublishDate() {
        return publishDate;
    }

    public double getPrice() {
        return price;
    }

    public int getTotal() {
        return total;
    }

    public int getBorrowed() {
        return borrowed;
    }

    public boolean isAvailable() {
        return borrowed < total;
    }

    public void borrow() {
        borrowed++;
    }

    public void returnBook() {
        borrowed--;
    }
}

读者库类：

public class ReaderLibrary {
    private List<Reader> readers; // 读者列表

    public ReaderLibrary() {
        readers = new ArrayList<>();
    }

    public void addReader(Reader reader) {
        readers.add(reader);
    }

    public Reader findReaderById(String id) {
        for (Reader reader : readers) {
            if (reader.getId().equals(id)) {
                return reader;
            }
        }
        return null;
    }

    public void deleteReader(Reader reader) {
        readers.remove(reader);
    }

    public void printReaders() {
        for (Reader reader : readers) {
            System.out.println("读者编号：" + reader.getId() + " 读者姓名：" + reader.getName());
        }
    }
}

图书库类：

public class BookLibrary {
    private List<Book> books; // 图书列表

    public BookLibrary() {
        books = new ArrayList<>();
    }

    public void addBook(Book book) {
        books.add(book);
    }

    public Book findBookById(String id) {
        for (Book book : books) {
            if (book.getId().equals(id)) {
                return book;
            }
        }
        return null;
    }

    public void deleteBook(Book book) {
        books.remove(book);
    }

    public void printAvailableBooks() {
        for (Book book : books) {
            if (book.isAvailable()) {
                System.out.println("图书编号：" + book.getId() + " 书名：" + book.getName() + " 作者：" + book.getAuthors() + " 出版社：" + book.getPublisher() + " 馆藏数：" + book.getTotal() + " 借阅数：" + book.getBorrowed());
            }
        }
    }
}

菜单类：

import java.util.Scanner;

public class Menu {
    private ReaderLibrary readerLibrary;
    private BookLibrary bookLibrary;

    public Menu(ReaderLibrary readerLibrary, BookLibrary bookLibrary) {
        this.readerLibrary = readerLibrary;
        this.bookLibrary = bookLibrary;
    }

    public void display() {
        Scanner scanner = new Scanner(System.in);
        int choice = 0;

        while (choice != 5) {
            System.out.println("1. 借书");
            System.out.println("2. 还书");
            System.out.println("3. 图书维护");
            System.out.println("4. 读者维护");
            System.out.println("5. 退出");
            System.out.print("请选择：");
            choice = scanner.nextInt();

            switch (choice) {
                case 1:
                    borrowBook();
                    break;
                case 2:
                    returnBook();
                    break;
                case 3:
                    bookMaintenance();
                    break;
                case 4:
                    readerMaintenance();
                    break;
                case 5:
                    System.out.println("退出");
                    break;
                default:
                    System.out.println("无效选项");
                    break;
            }
        }

        scanner.close();
    }

    private void borrowBook() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入读者编号：");
        String readerId = scanner.nextLine();
        Reader reader = readerLibrary.findReaderById(readerId);
        if (reader == null) {
            System.out.println("读者不存在");
            return;
        }

        System.out.print("请输入图书编号：");
        String bookId = scanner.nextLine();
        Book book = bookLibrary.findBookById(bookId);
        if (book == null) {
            System.out.println("图书不存在");
            return;
        }

        if (!book.isAvailable()) {
            System.out.println("图书已借完");
            return;
        }

        reader.borrowBook(book);
        book.borrow();
        System.out.println("借书成功");
    }

    private void returnBook() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入读者编号：");
        String readerId = scanner.nextLine();
        Reader reader = readerLibrary.findReaderById(readerId);
        if (reader == null) {
            System.out.println("读者不存在");
            return;
        }

        System.out.print("请输入图书编号：");
        String bookId = scanner.nextLine();
        Book book = null;
        for (Book borrowedBook : reader.getBooks()) {
            if (borrowedBook.getId().equals(bookId)) {
                book = borrowedBook;
                break;
            }
        }
        if (book == null) {
            System.out.println("读者未借阅该图书");
            return;
        }

        reader.returnBook(book);
        book.returnBook();
        System.out.println("还书成功");
    }

    private void bookMaintenance() {
        Scanner scanner = new Scanner(System.in);
        int choice = 0;

        while (choice != 4) {
            System.out.println("1. 新增图书");
            System.out.println("2. 删除图书");
            System.out.println("3. 查看可借图书");
            System.out.println("4. 返回");
            System.out.print("请选择：");
            choice = scanner.nextInt();

            switch (choice) {
                case 1:
                    addBook();
                    break;
                case 2:
                    deleteBook();
                    break;
                case 3:
                    printAvailableBooks();
                    break;
                case 4:
                    System.out.println("返回");
                    break;
                default:
                    System.out.println("无效选项");
                    break;
            }
        }
    }

    private void addBook() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入图书编号：");
        String id = scanner.nextLine();
        System.out.print("请输入书名：");
        String name = scanner.nextLine();
        System.out.print("请输入作者：");
        String author = scanner.nextLine();
        List<String> authors = new ArrayList<>();
        authors.add(author);
        System.out.print("请输入出版社：");
        String publisher = scanner.nextLine();
        System.out.print("请输入出版日期：");
        String publishDate = scanner.nextLine();
        System.out.print("请输入定价：");
        double price = scanner.nextDouble();
        System.out.print("请输入馆藏数：");
        int total = scanner.nextInt();

        Book book = new Book(id, name, authors, publisher, publishDate, price, total, 0);
        bookLibrary.addBook(book);
        System.out.println("新增图书成功");
    }

    private void deleteBook() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入图书编号：");
        String id = scanner.nextLine();
        Book book = bookLibrary.findBookById(id);
        if (book == null) {
            System.out.println("图书不存在");
            return;
        }

        bookLibrary.deleteBook(book);
        System.out.println("删除图书成功");
    }

    private void printAvailableBooks() {
        bookLibrary.printAvailableBooks();
    }

    private void readerMaintenance() {
        Scanner scanner = new Scanner(System.in);
        int choice = 0;

        while (choice != 4) {
            System.out.println("1. 新增读者");
            System.out.println("2. 删除读者");
            System.out.println("3. 查看读者列表");
            System.out.println("4. 返回");
            System.out.print("请选择：");
            choice = scanner.nextInt();

            switch (choice) {
                case 1:
                    addReader();
                    break;
                case 2:
                    deleteReader();
                    break;
                case 3:
                    printReaders();
                    break;
                case 4:
                    System.out.println("返回");
                    break;
                default:
                    System.out.println("无效选项");
                    break;
            }
        }
    }

    private void addReader() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入读者编号：");
        String id = scanner.nextLine();
        System.out.print("请输入读者姓名：");
        String name = scanner.nextLine();

        Reader reader = new Reader(id, name);
        readerLibrary.addReader(reader);
        System.out.println("新增读者成功");
    }

    private void deleteReader() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入读者编号：");
        String id = scanner.nextLine();
        Reader reader = readerLibrary.findReaderById(id);
        if (reader == null) {
            System.out.println("读者不存在");
            return;
        }

        readerLibrary.deleteReader(reader);
        System.out.println("删除读者成功");
    }

    private void printReaders() {
        readerLibrary.printReaders();
    }
}

主程序：

public class Main {
    public static void main(String[] args) {
        ReaderLibrary readerLibrary = new ReaderLibrary();
        BookLibrary bookLibrary = new BookLibrary();
        Menu menu = new Menu(readerLibrary, bookLibrary);
        menu.display();
    }
}

这个代码只是一个简单实现，还有很多需要改进的地方，比如数据的持久化、输入输出的校验、逾期罚款的计算等。但是这个代码可以作为一个参考，帮助你了解如何用Java实现一个图书管理系统。