将数据写入多个Google Cloud Storage buckets

Question

我正在写一个服务，这将写入数据到不同的谷歌云存储帐户。帐户的所有者应该“注册”我的服务，我将定期将数据写入他们的帐户存储桶中。

我想让“注册”尽可能简单。我仍然在试图理解谷歌的OAuth2。我该如何做到这一点？我想用JAVA以编程方式编写数据

Answer 1

它的工作方式是，你的应用程序请求用户的同意，用户告诉谷歌这个同意，谷歌给你代表该用户采取行动的凭证。因为涉及到三方，所以这被称为3条腿的OAuth (3LO)。

下面是这个OAuth流程的概述：https://developers.google.com/identity/protocols/OAuth2WebServer#overview

下面是一个使用Java库构建它的示例：https://developers.google.com/api-client-library/java/google-api-java-client/oauth2#web_server_applications

下面是该示例中的Java代码的重要部分：

public class CalendarServletSample extends AbstractAuthorizationCodeServlet {

  @Override
  protected void doGet(HttpServletRequest request, HttpServletResponse response)
      throws IOException {
    // do stuff
  }

  @Override
  protected String getRedirectUri(HttpServletRequest req) throws ServletException, IOException {
    GenericUrl url = new GenericUrl(req.getRequestURL().toString());
    url.setRawPath("/oauth2callback");
    return url.build();
  }

  @Override
  protected AuthorizationCodeFlow initializeFlow() throws IOException {
    return new GoogleAuthorizationCodeFlow.Builder(
        new NetHttpTransport(), JacksonFactory.getDefaultInstance(),
        "[[ENTER YOUR CLIENT ID]]", "[[ENTER YOUR CLIENT SECRET]]",
        Collections.singleton(CalendarScopes.CALENDAR)).setDataStoreFactory(
        DATA_STORE_FACTORY).setAccessType("offline").build();
  }

  @Override
  protected String getUserId(HttpServletRequest req) throws ServletException, IOException {
    // return user ID
  }
}

public class CalendarServletCallbackSample extends AbstractAuthorizationCodeCallbackServlet {

  @Override
  protected void onSuccess(HttpServletRequest req, HttpServletResponse resp, Credential credential)
      throws ServletException, IOException {
    resp.sendRedirect("/");
  }

  @Override
  protected void onError(
      HttpServletRequest req, HttpServletResponse resp, AuthorizationCodeResponseUrl errorResponse)
      throws ServletException, IOException {
    // handle error
  }

  @Override
  protected String getRedirectUri(HttpServletRequest req) throws ServletException, IOException {
    GenericUrl url = new GenericUrl(req.getRequestURL().toString());
    url.setRawPath("/oauth2callback");
    return url.build();
  }

  @Override
  protected AuthorizationCodeFlow initializeFlow() throws IOException {
    return new GoogleAuthorizationCodeFlow.Builder(
        new NetHttpTransport(), JacksonFactory.getDefaultInstance()
        "[[ENTER YOUR CLIENT ID]]", "[[ENTER YOUR CLIENT SECRET]]",
        Collections.singleton(CalendarScopes.CALENDAR)).setDataStoreFactory(
        DATA_STORE_FACTORY).setAccessType("offline").build();
  }

  @Override
  protected String getUserId(HttpServletRequest req) throws ServletException, IOException {
    // return user ID
  }
}

您应该注意到，这段代码是围绕常见的Java "Servlet“模型构建的，它还假设您使用某种数据存储来记住用户的刷新令牌。整个OAuth舞蹈的最终结果是获得一个“刷新令牌”，您可以定期使用它来获得一个临时的“会话令牌”，该令牌可以持续长达一个小时。您需要使用某种类型的数据存储来记住所有这些令牌。