小编sam*_*ias的帖子

我想访问一些Google API服务：

• GDrive API
• 联系API
• 人物API

而且，我正在努力使用oauth2模拟服务帐户流程（您知道一个：Google Oauth v2- 服务帐户说明。要进行模拟，您需要在google应用程序控制台中应用“委派整个域的权限”，请下载相应的pk12文件并在Google控制台项目中激活api。

此刻我总是得到：

com.google.api.client.auth.oauth2.TokenResponseException: 401 Unauthorized
at com.google.api.client.auth.oauth2.TokenResponseException.from(TokenResponseException.java:105)
at com.google.api.client.auth.oauth2.TokenRequest.executeUnparsed(TokenRequest.java:287)
at com.google.api.client.auth.oauth2.TokenRequest.execute(TokenRequest.java:307)
at com.google.api.client.googleapis.auth.oauth2.GoogleCredential.executeRefreshToken(GoogleCredential.java:384)
at com.google.api.client.auth.oauth2.Credential.refreshToken(Credential.java:489)
at oauthsample.GDriveAPI.<init>(GDriveAPI.java:50)
at oauthsample.GDriveAPI.main(GDriveAPI.java:85)

这是我的代码：

        HttpTransport httpTransport = new NetHttpTransport();
        JacksonFactory jsonFactory = new JacksonFactory();    

        Set<String> scopes = new HashSet<String>();
        scopes.add("https://www.google.com/m8/feeds");

        GoogleCredential credential = new GoogleCredential.Builder()
                .setTransport(httpTransport)
                .setJsonFactory(JSON_FACTORY)
                .setServiceAccountId("myserviceuser@xxxxxx.iam.account.com")
                .setServiceAccountPrivateKeyFromP12File(new File("somep12key.p12"))
                .setServiceAccountScopes(scopes)
                .setServiceAccountUser("my_user_name@gmail.com")
                .build();

       credential.refreshToken();
       ContactsService service = new ContactsService("MYAPP");
        service.getRequestFactory().setHeader("User-Agent", "MYAPP");
        service.setHeader("GData-Version", "3.0");
        service.setOAuth2Credentials(credential);

        URL feedUrl = new URL("https://www.google.com/m8/feeds/contacts/default/full");
        ContactFeed resultFeed = service.getFeed(feedUrl, …