Unknown authorization header - Error 401

Question

I am accessing Google Spreadsheet feeds using HMAC-SH1 sign. My Code is :

GoogleOAuthParameters oauthParameters = new GoogleOAuthParameters();
        oauthParameters.setOAuthConsumerKey(CONSUMER_KEY);
        oauthParameters.setOAuthConsumerSecret(CONSUMER_SECRET);
        oauthParameters.setScope("https://spreadsheets.google.com/feeds/");
        oauthParameters.setOAuthType(OAuthParameters.OAuthType.THREE_LEGGED_OAUTH);
        oauthParameters.setOAuthToken(request.getSession().getAttribute("oauth_token").toString());
        oauthParameters.setOAuthTokenSecret(request.getSession().getAttribute("oauth_token_secret").toString());

GoogleService googleService = new GoogleService("wise", "searceapps-searcegadget2-1");
        googleService.setOAuthCredentials(oauthParameters, new OAuthHmacSha1Signer());
        URL feedUrl = new URL("https://spreadsheets.google.com/feeds/spreadsheets/private/full/");

        SpreadsheetFeed resultFeed = googleService.getFeed(feedUrl, SpreadsheetFeed.class);

But, I am getting the error :

Oauth.requestServlet doGet: null com.google.gdata.util.AuthenticationException: OK Unknown authorization header

Unknown authorization header

Error 401

at com.google.gdata.client.http.HttpGDataRequest.handleErrorResponse(HttpGDataRequest.java:600) at com.google.gdata.client.http.GoogleGDataRequest.handleErrorResponse(GoogleGDataRequest.java:563) at com.google.gdata.client.http.HttpGDataRequest.checkResponse(HttpGDataRequest.java:552) at com.google.gdata.client.http.HttpGDataRequest.execute(HttpGDataRequest.java:530) at com.google.gdata.client.http.GoogleGDataRequest.execute(GoogleGDataRequest.java:535) at com.google.gdata.client.Service.getFeed(Service.java:1135) at com.google.gdata.client.Service.getFeed(Service.java:998) at com.google.gdata.client.GoogleService.getFeed(GoogleService.java:631) at com.google.gdata.client.Service.getFeed(Service.java:1017) at Oauth.accessFeeds.access(accessFeeds.java:74)

What is the problem with this ?