retrieveRequestToken(CommonsHttpOAuthConsumer,CALLBACK_URI) functions throws OAuthCommunicationException

I want to make an android app which will update status in twitter.
I am using signpost-core-1.2.1.1 and signpost-commonshttp4-1.2.1.1 jar files.I have given internet uses permission and i have registered app in twitter giving read,write and direct messages permission. Also filled up the callback Url.

code snippet:

private  static  final  String CALLBACK_URI = "app://twitter";
 private static final String REQUEST_TOKEN_URL = "https://api.twitter.com/oauth/request_token";
 private static final String ACCESS_TOKEN_URL = "https://api.twitter.com/oauth/access_token";
 private static final String AUTHORIZE_URL = "https://api.twitter.com/oauth/authorize";
 
 String CONSUMER_KEY = "I4bwezijxf6VwpU8x0tygg";
 String CONSUMER_SECRET = "Y6vSdZs3zWBrNogXZWSHKZ590RSXqB5wBwj8vFaayk";
 
 private static  CommonsHttpOAuthConsumer consumer;
 private static CommonsHttpOAuthProvider provider;
 
 consumer = new CommonsHttpOAuthConsumer(CONSUMER_KEY, CONSUMER_SECRET);
 provider = new DefaultOAuthProvider(REQUEST_TOKEN_URL,ACCESS_TOKEN_URL, AUTHORIZE_URL);
 String authUrl="";
 
 authUrl = provider.retrieveRequestToken(consumer,CALLBACK_URI);
 

I am totally stuck with this.Please reply.

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