Google oauth java 客户端获取访问令牌失败，并显示“400 Bad Request {“error”：“invalid_request”}”

我正在使用此处显示的“Web 服务器应用程序”示例。在我的回调 servlet 中，我想检索访问令牌，但无法成功执行此操作。 以下是我的代码

  @Override
  protected String getUserId(HttpServletRequest req) throws ServletException, IOException {
    // return user ID
      Iterator<String> iterator = req.getParameterMap().keySet().iterator();
        while (iterator.hasNext()) {
            String string = iterator.next();

            System.out.println(string+"---++--"+req.getParameter(string));
        }
        GoogleAuthorizationCodeTokenRequest newTokenRequest = new GoogleAuthorizationCodeFlow.Builder(new NetHttpTransport(), new JacksonFactory(),
                                                             "2XXXXXX7218.apps.googleusercontent.com", "KugD_XXX_7vqnGZVXXXXX1M",
                                                              Collections.singleton("https://gdata.youtube.com"))
                                                              .build().newTokenRequest(req.getParameter("code"));
        //GoogleAuth
        GoogleTokenResponse token = newTokenRequest.setRedirectUri("/").execute();
        String accessToken = token.getAccessToken();
        System.out.println("accesstoken:"+accessToken);
        return "";
  }

运行此代码后，我收到以下错误

com.google.api.client.auth.oauth2.TokenResponseException: 400 Bad Request
{
  "error" : "invalid_request"
}

简而言之，我得到“代码”参数（请求代码），我不知道如何将其转换为访问令牌。 我已经看过了Google API - 从 Oauth2 请求令牌返回“invalid_request” Google OAuth 2：令牌请求上的response_type错误但我的代码中没有太多可以使用的东西

EDIT

谷歌 API 不适合我，所以我在不使用任何库的情况下编写了以下代码

 URL url = new URL("https://accounts.google.com/o/oauth2/token");
    connection = (HttpURLConnection) url.openConnection();
    String urlParameters = "code=" + req.getParameter("code") + "&client_id=29852.apps.googleusercontent.com&client_secret=KugD_LVi_7vqnssssxxxNRBz1M"+
            "&redirect_uri=https://flixomnia.com/oauth2callback&grant_type=authorization_code&scope=https://gdata.youtube.com&response_type=token";
    connection.setDoOutput(true);
    connection.setDoInput(true);
    connection.setInstanceFollowRedirects(true);
    connection.setRequestMethod("POST");
    connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
    connection.setRequestProperty("Authorization", "Bearer 4/q3Xh_pJI458XXXXXXXkh-lxe3-8.cmaD6o7V5BkQXE-XXXXX-edgI");
    connection.setRequestProperty("Content-Length", "" + Integer.toString(urlParameters.getBytes().length));
    connection.setRequestProperty("X-GData-Key", "key=AI39siXXXXXXM7tyHBvXEM1lLcORetit6QSArQ3sjelBxXXXXXXtgLSPdZPxvsF_vkntOQMnAEYAuVFqhN7oUw");
    connection.setRequestProperty("GData-Version", "2");

    connection.setUseCaches(false);
    //com.google.gdata.client.youtube.YouTubeService service = new com.google.gdata.client.youtube.YouTubeService("","");
    //YouTubeMediaGroup g = new YouTubeMediaGroup();


    DataOutputStream wr = new DataOutputStream(connection.getOutputStream());

    wr.writeBytes(urlParameters);
    wr.flush();
    InputStream inputStream = connection.getInputStream();
    byte[] b = new byte[1024];
    while (inputStream.read(b) != -1) {
        System.out.print(new String(b));

    }
    System.out.println("");
    wr.close();
    connection.disconnect();

但我仍然收到以下错误

    {  "error" : "invalid_request"}
java.io.IOException: Server returned HTTP response code: 400 for URL: https://accounts.google.com/o/oauth2/token
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1615)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254)
    at com.broadcastr.servlets.YouTubeCallbackService.getUserId(YouTubeCallbackService.java:168)
    at com.google.api.client.extensions.servlet.auth.oauth2.AbstractAuthorizationCodeCallbackServlet.doGet(AbstractAuthorizationCodeCallbackServlet.java:130)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1001)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)

1. In the setRedirectUri上面初始代码中的方法来获取访问令牌，redirect_uri设置不正确。这redirect_uri应使用客户注册时指定的信息。

2. 在编辑代码中，在将所需参数发送到访问令牌端点时，不支持的参数response_type也与请求一起发送。删除response_type参数应该解决目的。

   另外，根据OAuth2 RFC 草案，访问令牌端点也可能出错invalid_request如果请求使用不止一种机制来验证客户端。因此，删除Authorization标头到URLConnection也应该解决目的。