请你把以上代码重新写一下，有语法错误

根据您提供的文档内容，我为您整理了一个基于 Python 的图书管理系统的示例代码。请注意，此代码已尽量遵循您的需求进行了编写，并加入了适当的异常处理以增强其健壮性。以下是完整的代码：

import json
from typing import List, Optional

class Book:
    def __init__(self, book_id: int, title: str, author: str, year: int):
        self.__book_id = book_id
        self.__title = title
        self.__author = author
        self.__year = year
        self.__is_borrowed = False

    @property
    def id(self) -> int:
        return self.__book_id

    @property
    def title(self) -> str:
        return self.__title

    @property
    def author(self) -> str:
        return self.__author

    @property
    def year(self) -> int:
        return self.__year

    @property
    def is_borrowed(self) -> bool:
        return self.__is_borrowed

    def set_is_borrowed(self, value: bool):
        self.__is_borrowed = value

    def display_info(self):
        print(f"ID: {self.__book_id}, Title: {self.__title}, Author: {self.__author}, Year: {self.__year}")

class Library:
    def __init__(self, file_path: str = "library_data.json"):
        self.file_path = file_path
        self.books: List[Book] = []
        self.load_books()

    def add_book(self, book: Book):
        if any(b.id == book.id for b in self.books):
            raise ValueError("A book with this ID already exists.")
        self.books.append(book)
        self.save_books()
        print(f"Book '{book.title}' added successfully.")

    def remove_book(self, book_id: int):
        book_to_remove = next((b for b in self.books if b.id == book_id), None)
        if not book_to_remove:
            raise ValueError("No book found with the given ID.")
        self.books.remove(book_to_remove)
        self.save_books()
        print(f"Book with ID {book_id} removed successfully.")

    def update_book(self, book_id: int, **kwargs):
        book_to_update = next((b for b in self.books if b.id == book_id), None)
        if not book_to_update:
            raise ValueError("No book found with the given ID.")
        for key, value in kwargs.items():
            setattr(book_to_update, f"_{key}", value)
        self.save_books()
        print(f"Book with ID {book_id} updated successfully.")

    def find_book(self, book_id: int) -> Optional[Book]:
        return next((b for b in self.books if b.id == book_id), None)

    def list_all_books(self):
        for book in self.books:
            book.display_info()

    def borrow_book(self, book_id: int):
        book = self.find_book(book_id)
        if not book:
            raise ValueError("No book found with the given ID.")
        if book.is_borrowed:
            raise ValueError("This book is currently borrowed by someone else.")
        book.set_is_borrowed(True)
        self.save_books()
        print(f"Book with ID {book_id} has been borrowed.")

    def return_book(self, book_id: int):
        book = self.find_book(book_id)
        if not book:
            raise ValueError("No book found with the given ID.")
        if not book.is_borrowed:
            raise ValueError("This book was not borrowed before.")
        book.set_is_borrowed(False)
        self.save_books()
        print(f"Book with ID {book_id} has been returned.")

    def load_books(self):
        try:
            with open(self.file_path, 'r') as file:
                data = json.load(file)
                self.books = [Book(**book_data) for book_data in data]
        except FileNotFoundError:
            pass  # File does not exist, start with an empty library.
        except Exception as e:
            print(f"Error loading books from file: {e}")

    def save_books(self):
        try:
            with open(self.file_path, 'w') as file:
                data = [{"book_id": b.id, "title": b.title, "author": b.author, "year": b.year, "is_borrowed": b.is_borrowed} for b in self.books]
                json.dump(data, file, indent=4)
        except Exception as e:
            print(f"Error saving books to file: {e}")

def main():
    library = Library()
    while True:
        print("\n1. Add Book\n2. Remove Book\n3. Update Book\n4. Find Book\n5. Borrow Book\n6. Return Book\n7. List All Books\n8. Exit")
        choice = input("Enter your choice: ")
        
        if choice == '1':
            book_id = int(input("Enter book ID: "))
            title = input("Enter book title: ")
            author = input("Enter book author: ")
            year = int(input("Enter publication year: "))
            book = Book(book_id, title, author, year)
            library.add_book(book)
            
        elif choice == '2':
            book_id = int(input("Enter book ID to remove: "))
            library.remove_book(book_id)
            
        elif choice == '3':
            book_id = int(input("Enter book ID to update: "))
            field = input("Enter field to update (title/author/year): ")
            new_value = input("Enter new value: ")
            library.update_book(book_id, **{field: new_value})
            
        elif choice == '4':
            book_id = int(input("Enter book ID to find: "))
            book = library.find_book(book_id)
            if book:
                book.display_info()
            else:
                print("No book found with the given ID.")
                
        elif choice == '5':
            book_id = int(input("Enter book ID to borrow: "))
            library.borrow_book(book_id)
            
        elif choice == '6':
            book_id = int(input("Enter book ID to return: "))
            library.return_book(book_id)
            
        elif choice == '7':
            library.list_all_books()
            
        elif choice == '8':
            break
        
        else:
            print("Invalid choice, please try again.")

if __name__ == "__main__":
    main()

### 关键点说明：
1. **类设计**：
- `Book` 类封装了图书的信息，包括 ID、标题、作者、出版年份和是否被借出状态。
- `Library` 类管理图书的集合，提供了添加、删除、更新、查找、借阅和归还等功能。

2. **文件管理**：
- 使用 JSON 文件进行数据的持久化存储。`load_books` 和 `save_books` 方法分别用于加载和保存图书数据。

3. **异常处理**：
- 在关键操作中加入了异常处理，确保程序在遇到错误时能够给出合理的提示。

4. **用户交互**：
- 提供了一个简单的命令行界面，用户可以通过输入数字选择不同的操作。

希望这段代码能满足您的需求！如果有任何进一步的问题或需要调整的地方，请告诉我。