代理背后的 Google Drive API Java 客户端

我正在尝试使用 Drive API 编写一个 java 客户端驱动器 API v2 https://developers.google.com/resources/api-libraries/documentation/drive/v2/java/latest/。但是，我在尝试在代码中执行 OAuth2 身份验证时遇到错误。我认为这可能是代理问题，我尝试通过在代码中设置代理来解决该问题，但没有帮助。

This https://developers.google.com/drive/v2/web/quickstart/java#prerequisites是我提到的编写程序的指南。

这是我的代码片段：

public static Credential authorize() throws IOException {
            // Load client secrets.
            Credential credential = null;

            try{

            GoogleClientSecrets clientSecrets =
                GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(new FileInputStream("client_secret.json")));

            // Build flow and trigger user authorization request.

            GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
                      HTTP_TRANSPORT, JSON_FACTORY, clientSecrets,
                      Collections.singleton(DriveScopes.DRIVE)).setDataStoreFactory(
                      DATA_STORE_FACTORY).build();

            credential = new AuthorizationCodeInstalledApp(
                flow, new LocalServerReceiver()).authorize("user");

            System.out.println(
                    "Credentials saved to " + DATA_STORE_DIR.getAbsolutePath());
            }catch(Exception e){
                e.printStackTrace(); System.exit(0);
                }
            return credential;

        }

        /**
         * Build and return an authorized Drive client service.
         * @return an authorized Drive client service
         * @throws IOException
         */
        public static Drive getDriveService() throws IOException {
            System.setProperty("http.proxyHost","10.3.100.207") ;
            System.setProperty("http.proxyPort", "8080") ;

            Credential credential = authorize();
            return new Drive.Builder(
                    HTTP_TRANSPORT, JSON_FACTORY, credential)
                    .setApplicationName(APPLICATION_NAME)
                    .build();
        }

这是堆栈跟踪：

2016-05-19 18:41:54.989:INFO::Logging to STDERR via org.mortbay.log.StdErrLog
2016-05-19 18:41:54.990:INFO::jetty-6.1.26
2016-05-19 18:41:55.001:INFO::Started SocketConnector@localhost:51307
Please open the following address in your browser:
  https://accounts.google.com/o/oauth2/auth?client_id=904439877486-uqiqmstss1bdcmhabt0gom905jo3hqsv.apps.googleusercontent.com&redirect_uri=http://localhost:51307/Callback&response_type=code&scope=https://www.googleapis.com/auth/drive
2016-05-19 18:42:28.496:INFO::Stopped SocketConnector@localhost:51307
java.net.UnknownHostException: accounts.google.com
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:668)
at sun.net.NetworkClient.doConnect(NetworkClient.java:175)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:432)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:527)
at sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:264)
at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:367)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:191)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1105)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:999)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:177)
at sun.net.www.protocol.http.HttpURLConnection.getOutputStream0(HttpURLConnection.java:1283)
at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(HttpURLConnection.java:1258)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getOutputStream(HttpsURLConnectionImpl.java:250)
at com.google.api.client.http.javanet.NetHttpRequest.execute(NetHttpRequest.java:77)
at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:981)
at com.google.api.client.auth.oauth2.TokenRequest.executeUnparsed(TokenRequest.java:283)
at com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeTokenRequest.execute(GoogleAuthorizationCodeTokenRequest.java:158)
at com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeTokenRequest.execute(GoogleAuthorizationCodeTokenRequest.java:79)
at com.google.api.client.extensions.java6.auth.oauth2.AuthorizationCodeInstalledApp.authorize(AuthorizationCodeInstalledApp.java:82)
at DriveAPITest.authorize(DriveAPITest.java:84)
at DriveAPITest.getDriveService(DriveAPITest.java:104)
at DriveAPITest.main(DriveAPITest.java:116)
Exception in thread "main" java.net.UnknownHostException: www.googleapis.com
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:668)
at sun.net.NetworkClient.doConnect(NetworkClient.java:175)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:432)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:527)
at sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:264)
at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:367)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:191)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1105)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:999)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:177)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:153)
at com.google.api.client.http.javanet.NetHttpRequest.execute(NetHttpRequest.java:93)
at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:981)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:419)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:352)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.execute(AbstractGoogleClientRequest.java:469)
at DriveAPITest.main(DriveAPITest.java:121)

我打开浏览器的身份验证链接，批准权限后显示以下消息：

收到验证码。您现在可以关闭此窗口...

希望有人能指出我正确的方向。

您应该定义您的代理和 HttpTransport：

final Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("your address", port));
final HttpTransport httpTransport = new NetHttpTransport.Builder().setProxy(proxy).build();

// Build flow and trigger user authorization request.
GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(httpTransport, JSON_FACTORY, clientSecrets, SCOPES)
                                        .setDataStoreFactory(DATA_STORE_FACTORY)
                                        .setAccessType("offline")
                                        .build();