使用 Google OAuth2 API 对 Google App 用户进行身份验证

Question

我想知道是否可以使用 google 客户端 api (java) 向我的应用程序验证 google 应用程序域的用户。 目标应用程序是使用 REST 后端（球衣）的 Web 应用程序。

documentation 不是很清楚（或者我误解了它），文档中的示例指的是已弃用的类......有人知道这是否可能以及最好的方法。

代码示例将不胜感激。

Answer 1

Google Apps 帐户应该可以正常使用 API。

唯一的例外是域管理员禁用了该服务。例如，如果域管理员禁用了 Google+ 功能，您将无法访问该用户的 Google+ 数据。

无需更改代码，因此您应该能够使用来自任何samples in the client library repository 或产品特定示例（如this one for Google+）的代码。

Google+ 入门项目首先通过在 com.google.api.sample.OAuth2AuthorizationCodeServlet 中扩展 AbstractAuthorizationCodeServlet 来实现 OAuth 流程

public class OAuth2AuthorizationCodeServlet 
    extends AbstractAuthorizationCodeServlet {
    /**
     * If the user already has a valid credential held in the 
     * AuthorizationCodeFlow they are simply returned to the home page.
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
                    throws ServletException, IOException {
        response.sendRedirect("/");
    }

    /**
     * Returns the URI to redirect to with the authentication result.
     */
    @Override
    protected String getRedirectUri(HttpServletRequest request)
                    throws ServletException, IOException {
        return ConfigHelper.REDIRECT_URI;
    }

    /**
     * Returns the HTTP session id as the identifier for the current user.  
     * The users credentials are stored against this ID.
     */
    @Override
    protected String getUserId(HttpServletRequest request)
                    throws ServletException, IOException {
        return request.getSession(true).getId();
    }

    @Override
    protected AuthorizationCodeFlow initializeFlow() throws ServletException,
                    IOException {
        return Util.getFlow();
    }
}

然后通过扩展AbstractAuthorizationCodeCallbackServlet 来完成com.google.api.sample.Oauth2CallbackServlet 中的流程：

public class OAuth2CallbackServlet 
    extends AbstractAuthorizationCodeCallbackServlet {    
    @Override
    protected void onSuccess(HttpServletRequest request, 
            HttpServletResponse response, Credential credential)
            throws ServletException, IOException {
        response.sendRedirect("/");
    }

    @Override
    protected void onError(HttpServletRequest req, HttpServletResponse resp, 
            AuthorizationCodeResponseUrl errorResponse)
            throws ServletException, IOException {
        resp.sendError(SC_INTERNAL_SERVER_ERROR, "Something went wrong :(");
    }

    @Override
    protected String getRedirectUri(HttpServletRequest request) 
            throws ServletException, IOException {
        return ConfigHelper.REDIRECT_URI;
    }

    @Override
    protected AuthorizationCodeFlow initializeFlow() 
            throws IOException {
        return Util.getFlow();
    }

    @Override
    protected String getUserId(HttpServletRequest request) throws ServletException, IOException {
        return  request.getSession(true).getId(); 
    }

}