Google Books API 仅返回 10 个结果

Question

我正在实现一个 PHP 应用程序，这是第一次需要来自 Google Books API 的一些数据。 这很尴尬，但是当我使用典型的查询时 http://books.google.com/books/feeds/volumes?q=search+term（有具体API经验的可以理解我），只返回10个结果。

例如，http://books.google.com/books/feeds/volumes?q=php 的 XML 响应包含以下字段：totalResults>582。但是，我只检索到 10 个。

看了相应的文档，我还没有得出解决办法。

谁能帮帮我？

Answer 1

如今，关键字是 maxResults 而不是 max-results，就像raina77ow 的回答一样。 Source。正如文档所说，一次可以检索的最大书籍数量是 40。但是，您可以通过多个请求来克服这个限制，例如使用这个 PHP 函数：

private $books = array('items' => array());

/**
 * Searches the Google Books database through their public API
 * and returns the result. Notice that this function will (due to
 * Google's restriction) perform one request per 40 books.
 * If there aren't as many books as requested, those found will be
 * returned. If no books at all is found, false will be returned.
 * 
 * @author Dakniel
 * @param string $query Search-query, API documentation
 * @param int $numBooksToGet Amount of results wanted
 * @param int [optional] $startIndex Which index to start searching from
 * @return False if no book is found, otherwise the books
 */
private function getBooks($query, $numBooksToGet, $startIndex = 0) {

    // If we've already fetched all the books needed, or
    // all results are already stored
    if(count($this->books['items']) >= $numBooksToGet)
        return $this->books;

    $booksNeeded = $numBooksToGet - count($this->books['items']);

    // Max books / fetch = 40, this is therefore our limit
    if($booksNeeded > 40)
        $booksNeeded = 40;

    $url = "https://www.googleapis.com/books/v1/volumes?q=". urlencode($query) ."&startIndex=$startIndex&maxResults=$booksNeeded";

    // Get the data with cURL
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
    $bookBatch = curl_exec($ch);
    curl_close($ch);

    // If we got no matches..
    if($bookBatch['totalItems'] === 0) {

        // .. but we already have some books, return those
        if(count($this->books) > 0)
            return $this->books;
        else
            return false;

    }

    // Convert the JSON to an array and merge the existing books with
    // this request's new books 
    $bookBatch = json_decode($bookBatch, true);
    $this->books['items'] = array_merge($this->books['items'], $bookBatch['items']);

    // Even if we WANT more, but the API can't give us more: stop
    if( ($bookBatch['totalItems'] - count($this->books['items'])) === 0 ) {
        return $this->books;
    }

    // We need more books, and there's more to get: use recursion
    return $this->getBooks($query, $numBooksToGet, $startIndex);

}

简单示例用法：

$books = $this->getBooks("programming", 50);

这将返回最多 50 本与关键字编程相匹配的书籍。希望有人会使用这个，祝你好运！

Answer 2

不，它的另一个参数：max-results。但看起来一个“页面”中的最大结果数仍然设置得很低 - 为 20。

例如，这个查询：

http://books.google.com/books/feeds/volumes?q=php&max-results=40

... 只给了我 20 个条目。不过，您可以使用 start-index 参数遍历集合，这很有用，如下所示：

http://books.google.com/books/feeds/volumes?q=php&max-results=20&start-index=21

...然后是 41、61 等。它以 1 开头，而不是 0，我已经检查过了。 )

Answer 3

这就是我使用 ma​​xResults 参数获得 20 多个结果的方法

'https://www.googleapis.com/books/v1/volumes?q=inauthor:danielle%20steele&maxResults=40&key=your_very_own_api_key'

每个请求返回 40 个结果，轻而易举。请看下面的截图。