如何使用Google API PHP客户端获取OAuth2访问令牌

Question

我正在尝试获取OAuth访问令牌以将一些数据导入融合表。我正在尝试使用Google API PHP客户端。我为此目的创建了一个服务帐户，并且正在使用代码，主要来自serviceAccount示例：

function access_token()
{
    $client = new Google_Client();
    $client->setAuthClass ('Google_OAuth2');
    // ^ Don't know if this line is required,
    // ^ but it fails just as well without it.
    $client->setApplicationName ('Mysite.dom.ain');
    $client->setAssertionCredentials (new Google_AssertionCredentials
        (   '[e-mail]',
            array ('https://www.googleapis.com/auth/fusiontables'),
            file_get_contents ('path/to/my/privatekey.p12') ));
    $client->setClientId ('NUMBERS-LETTERS-DASHES.apps.googleusercontent.com');
    $client->authenticate();
    // ^ Also fails equally good with and without this line.
    return $client->getAccessToken();
}

一个小的调试输出显示$client->authenticate()返回true，但$client->getAcessToken()返回null。不会引发任何异常。我有一种感觉，我做错了什么。如果是这样，请原谅我的愚蠢，并指出我正确的方向。

Answer 1

不需要 authenticate（） 调用，但需要调用 refreshTokenWithAssertion() 来刷新基础访问令牌。如果使用客户端库发出签名请求，则在基础访问令牌已过期时，它将延迟地为你进行此调用。

刷新access_token的 API 请求成本高昂，并且配额较低，因此您需要缓存access_token。

// Set your client id, service account name, and the path to your private key.
// For more information about obtaining these keys, visit:
// https://developers.google.com/console/help/#service_accounts
const CLIENT_ID = 'INSERT_YOUR_CLIENT_ID';
const SERVICE_ACCOUNT_NAME = 'INSERT_YOUR_SERVICE_ACCOUNT_NAME';
// Make sure you keep your key.p12 file in a secure location, and isn't
// readable by others.
const KEY_FILE = '/super/secret/path/to/key.p12';
$client = new Google_Client();
$client->setApplicationName("Google FusionTable Sample");
// Set your cached access token. Remember to store the token in a real database instead of $_SESSION.
session_start();
if (isset($_SESSION['token'])) {
 $client->setAccessToken($_SESSION['token']);
}
$key = file_get_contents(KEY_FILE);
$client->setAssertionCredentials(new Google_AssertionCredentials(
    SERVICE_ACCOUNT_NAME,
    array('https://www.googleapis.com/auth/fusiontables'),
    $key)
);
$client->setClientId(CLIENT_ID);
if ($client->getAuth()->isAccessTokenExpired()) {
  $client->getAuth()->refreshTokenWithAssertion();
}
// Get the json encoded access token.
$token = $client->getAccessToken();

Answer 2

我认为您所做的一切都是正确的，现在您还剩下两个选择：

• 使用您的$client拨打类似内容的服务电话

    $service = new Google_FusiontablesService($client);
    $selectQuery = "select * from 1AwxQ46kfmPoYoq38e5CopJOWkCo_9GUU_ucD6zI";
    $service->query->sql($selectQuery)

• 或者调用内部函数refreshTokenWithAssertion()以获取令牌：

    $client::$auth->refreshTokenWithAssertion();
    $token = $client->getAccessToken(); //this should work now

对于这两种情况，我的 GitHub 存储库中都有示例。