java练习图书借阅管理系统

好的，我可以为您提供一个简单的Java练习图书借阅管理系统的实现思路。以下是实现的基本步骤：

1. 创建图书类 Book，包含属性：书名、作者、出版社、ISBN 等信息。

2. 创建用户类 User，包含属性：用户名、密码、已借图书列表等信息。

3. 创建图书馆类 Library，包含属性：图书列表、用户列表等信息，以及方法：添加图书、删除图书、借出图书、归还图书等。

4. 创建主程序类 Main，实现用户登录和菜单选择等功能。

具体的代码实现可以参考以下示例：

Book.java:

public class Book {
    private String title;
    private String author;
    private String publisher;
    private String ISBN;

    public Book(String title, String author, String publisher, String ISBN) {
        this.title = title;
        this.author = author;
        this.publisher = publisher;
        this.ISBN = ISBN;
    }

    public String getTitle() {
        return title;
    }

    public String getAuthor() {
        return author;
    }

    public String getPublisher() {
        return publisher;
    }

    public String getISBN() {
        return ISBN;
    }

    @Override
    public String toString() {
        return "Book{" +
                "title='" + title + '\'' +
                ", author='" + author + '\'' +
                ", publisher='" + publisher + '\'' +
                ", ISBN='" + ISBN + '\'' +
                '}';
    }
}

User.java:

import java.util.ArrayList;
import java.util.List;

public class User {
    private String username;
    private String password;
    private List<Book> borrowedBooks;

    public User(String username, String password) {
        this.username = username;
        this.password = password;
        this.borrowedBooks = new ArrayList<>();
    }

    public String getUsername() {
        return username;
    }

    public String getPassword() {
        return password;
    }

    public boolean borrowBook(Book book) {
        if (borrowedBooks.size() >= 3) {
            System.out.println("You have borrowed too many books!");
            return false;
        } else {
            borrowedBooks.add(book);
            return true;
        }
    }

    public boolean returnBook(Book book) {
        if (borrowedBooks.contains(book)) {
            borrowedBooks.remove(book);
            return true;
        } else {
            System.out.println("You haven't borrowed this book!");
            return false;
        }
    }

    public List<Book> getBorrowedBooks() {
        return borrowedBooks;
    }
}

Library.java:

import java.util.ArrayList;
import java.util.List;

public class Library {
    private List<Book> books;
    private List<User> users;

    public Library() {
        this.books = new ArrayList<>();
        this.users = new ArrayList<>();
    }

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

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

    public void addUser(User user) {
        users.add(user);
    }

    public void removeUser(User user) {
        users.remove(user);
    }

    public boolean borrowBook(User user, Book book) {
        if (!books.contains(book)) {
            System.out.println("The book is not available!");
            return false;
        } else {
            return user.borrowBook(book);
        }
    }

    public void returnBook(User user, Book book) {
        if (user.returnBook(book)) {
            books.add(book);
        }
    }

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

    public List<User> getUsers() {
        return users;
    }
}

Main.java:

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Library library = new Library();
        Book book1 = new Book("Java Programming", "John Smith", "Pearson", "978-0134685991");
        Book book2 = new Book("Data Structures and Algorithms", "Robert Lafore", "SAMS Publishing", "978-0672324536");
        Book book3 = new Book("Clean Code", "Robert C. Martin", "Prentice Hall", "978-0132350884");
        library.addBook(book1);
        library.addBook(book2);
        library.addBook(book3);
        User user1 = new User("alice", "123456");
        User user2 = new User("bob", "password");
        library.addUser(user1);
        library.addUser(user2);

        Scanner scanner = new Scanner(System.in);
        System.out.println("Welcome to the Library Management System!");
        System.out.print("Enter your username: ");
        String username = scanner.nextLine();
        System.out.print("Enter your password: ");
        String password = scanner.nextLine();
        User currentUser = null;
        for (User user : library.getUsers()) {
            if (user.getUsername().equals(username) && user.getPassword().equals(password)) {
                currentUser = user;
                break;
            }
        }
        if (currentUser == null) {
            System.out.println("Invalid username or password!");
            return;
        }

        while (true) {
            System.out.println("Please select an option:");
            System.out.println("1. View available books");
            System.out.println("2. Borrow a book");
            System.out.println("3. Return a book");
            System.out.println("4. View borrowed books");
            System.out.println("5. Exit");
            int choice = scanner.nextInt();
            scanner.nextLine(); // consume the newline character
            switch (choice) {
                case 1:
                    System.out.println("Available books:");
                    for (Book book : library.getBooks()) {
                        System.out.println(book);
                    }
                    break;
                case 2:
                    System.out.print("Enter the ISBN of the book you want to borrow: ");
                    String ISBN = scanner.nextLine();
                    Book bookToBorrow = null;
                    for (Book book : library.getBooks()) {
                        if (book.getISBN().equals(ISBN)) {
                            bookToBorrow = book;
                            break;
                        }
                    }
                    if (bookToBorrow == null) {
                        System.out.println("Invalid ISBN!");
                    } else {
                        if (library.borrowBook(currentUser, bookToBorrow)) {
                            System.out.println("You have successfully borrowed the book!");
                        }
                    }
                    break;
                case 3:
                    System.out.print("Enter the ISBN of the book you want to return: ");
                    ISBN = scanner.nextLine();
                    Book bookToReturn = null;
                    for (Book book : currentUser.getBorrowedBooks()) {
                        if (book.getISBN().equals(ISBN)) {
                            bookToReturn = book;
                            break;
                        }
                    }
                    if (bookToReturn == null) {
                        System.out.println("Invalid ISBN!");
                    } else {
                        library.returnBook(currentUser, bookToReturn);
                        System.out.println("You have successfully returned the book!");
                    }
                    break;
                case 4:
                    System.out.println("Borrowed books:");
                    for (Book book : currentUser.getBorrowedBooks()) {
                        System.out.println(book);
                    }
                    break;
                case 5:
                    System.out.println("Goodbye!");
                    return;
                default:
                    System.out.println("Invalid choice!");
                    break;
            }
        }
    }
}

这个图书借阅管理系统实现了基本的借书、还书、查看图书等功能，您可以在此基础上继续扩展和优化。