用Java语言开发一个spring框架的图书馆系统

好的，下面是一个简单的使用Spring框架开发的图书馆系统的Java代码示例，包括书籍类（Book）、用户类（User）、借阅记录类（BorrowRecord）、书籍服务类（BookService）和用户服务类（UserService）：

// 书籍类
public class Book {
    private String title;
    private String author;
    private boolean isBorrowed;

    public Book(String title, String author) {
        this.title = title;
        this.author = author;
        this.isBorrowed = false;
    }

    public String getTitle() {
        return title;
    }

    public String getAuthor() {
        return author;
    }

    public boolean isBorrowed() {
        return isBorrowed;
    }

    public void setBorrowed(boolean borrowed) {
        isBorrowed = borrowed;
    }
}

// 用户类
public class User {
    private String name;
    private int age;

    public User(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }
}

// 借阅记录类
public class BorrowRecord {
    private Book book;
    private User user;
    private Date borrowDate;
    private Date returnDate;

    public BorrowRecord(Book book, User user, Date borrowDate) {
        this.book = book;
        this.user = user;
        this.borrowDate = borrowDate;
    }

    public Book getBook() {
        return book;
    }

    public User getUser() {
        return user;
    }

    public Date getBorrowDate() {
        return borrowDate;
    }

    public Date getReturnDate() {
        return returnDate;
    }

    public void setReturnDate(Date returnDate) {
        this.returnDate = returnDate;
    }
}

// 书籍服务类
@Service
public class BookService {
    private List<Book> books = new ArrayList<>();

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

    public List<Book> getAvailableBooks() {
        return books.stream().filter(book -> !book.isBorrowed()).collect(Collectors.toList());
    }

    public Book getBookByTitle(String title) {
        return books.stream().filter(book -> book.getTitle().equals(title)).findFirst().orElse(null);
    }
}

// 用户服务类
@Service
public class UserService {
    private List<User> users = new ArrayList<>();

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

    public User getUserByName(String name) {
        return users.stream().filter(user -> user.getName().equals(name)).findFirst().orElse(null);
    }
}

// 图书馆类
@RestController
public class LibraryController {
    @Autowired
    private BookService bookService;

    @Autowired
    private UserService userService;

    private List<BorrowRecord> borrowRecords = new ArrayList<>();

    @GetMapping("/books")
    public List<Book> listBooks() {
        return bookService.getAvailableBooks();
    }

    @PostMapping("/borrow")
    public String borrowBook(@RequestParam String title, @RequestParam String userName) {
        Book book = bookService.getBookByTitle(title);
        if (book == null) {
            return "对不起，" + title + " 不是本图书馆的书籍！";
        }
        if (book.isBorrowed()) {
            return "对不起，" + title + " 已被借出！";
        }
        User user = userService.getUserByName(userName);
        if (user == null) {
            return "对不起，" + userName + " 不是本图书馆的用户！";
        }
        book.setBorrowed(true);
        BorrowRecord borrowRecord = new BorrowRecord(book, user, new Date());
        borrowRecords.add(borrowRecord);
        return user.getName() + " 借阅了 " + book.getTitle();
    }

    @PostMapping("/return")
    public String returnBook(@RequestParam String title) {
        Book book = bookService.getBookByTitle(title);
        if (book == null) {
            return "对不起，" + title + " 不是本图书馆的书籍！";
        }
        if (!book.isBorrowed()) {
            return "对不起，" + title + " 未被借出！";
        }
        BorrowRecord borrowRecord = borrowRecords.stream().filter(record -> record.getBook().equals(book) && record.getReturnDate() == null).findFirst().orElse(null);
        if (borrowRecord == null) {
            return "对不起，" + title + " 不是本图书馆的书籍或未被借出！";
        }
        borrowRecord.setReturnDate(new Date());
        book.setBorrowed(false);
        return "归还 " + book.getTitle() + " 成功！";
    }
}

// 测试
@SpringBootApplication
public class LibraryApplication {
    public static void main(String[] args) {
        SpringApplication.run(LibraryApplication.class, args);
    }
}

这个图书馆系统使用了Spring框架，包括了书籍类、用户类、借阅记录类、书籍服务类和用户服务类，同时使用了RestController注解来创建一个RESTful的Web服务，可以通过HTTP请求进行借阅和归还书籍操作。在这个示例中，使用了内存存储来保存书籍、用户和借阅记录信息，可以根据实际情况替换为数据库存储。