private String post() {
   uploadUrl = "https://upload.twitter.com/1.1/media/upload.json";
   HttpParameter[] params = new HttpParameter[1];
   try {
     InputStream is = new FileInputStream(new File(this.photo));
     params[0] = new HttpParameter("media", photo, is);
     postParameter = params;
   } catch (Exception e) {
     e.printStackTrace();
   }
   headers.putAll(client.getRequestHeaders());
   HttpRequest req = new HttpRequest(RequestMethod.POST, uploadUrl, postParameter, null, headers);
   String authheader = oauth.getAuthorizationHeader(req);
   headers.put("Authorization", authheader);
   HttpRequest req2 = new HttpRequest(RequestMethod.POST, uploadUrl, postParameter, null, headers);
   try {
     httpResponse = client.request(req2, null);
     if (httpResponse.getStatusCode() != 202) {
       Log.e(
           "Error from Twitter",
           "get error in post:"
               + httpResponse.getStatusCode()
               + ", details:"
               + httpResponse.toString());
     }
     return httpResponse.asJSONObject().getString("media_id_string");
   } catch (Exception e) {
     e.printStackTrace();
   }
   return null;
 }