根据ISBN获取豆瓣API提供的图书信息

/* 
Description: 获取利用豆瓣API根据ISBN取图书信息.
Author: 老蟹
License: GPL v2

book对象利用方法:
    $book = get_book_data($isbn); 
    $title = $book->getTitle();
    if(!isset($title)) {
        $message = "此书未找到.";
    }else{
        ....
    }
*/
// 取Book信息
function get_book_data($isbn) {
    $url = "https://api.douban.com/v2/book/isbn/:".$isbn;
        
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    
    $result = curl_exec($curl);
    curl_close($curl);
    
    $book_array = (array) json_decode($result, true);
    
    if(!empty($book_array["title"])) {
        $book_title = $book_array["title"];
        $book_author = $book_array["authors"][0];
        $book_cover = $book_array["image"];
        $book_isbn = $book_array["isbn13"]; // ISBN13
        $book_info = $book_array["summary"];        
        $book = new Book($book_title, $book_isbn, $book_author, $book_cover, $book_info);
        return $book;
    }
    
}
    
// 这里只取几个主要信息
class Book {    
    private $book_title;
    private $book_isbn;
    private $author;
    private $book_cover;
    private $book_info;

    public function __construct($book_title, $book_isbn, $author, $book_cover, $book_info) {
        $this->author = $author;
        $this->book_isbn = $book_isbn;
        $this->book_cover = $book_cover;
        $this->book_title = $book_title;
        $this->book_info = $book_info;
    }
    public function getTitle() {
        return $this->book_title;
    }
    public function getISBN() {
        return $this->book_isbn;
    }
    public function getAuthor() {
        return $this->author;
    }
    public function getCover() {
        return $this->book_cover;
    }    
    public function getBookInfo() {
        return $this->book_info;    
    }    
}