Exception while trying to tweet using twitter4j

问题

Exception while trying to tweet Twitter Login Error , This Exception occurs after the login is done and activity is recalled.

if (uri != null && uri.toString().startsWith(TWITTER_CALLBACK_URL)) {
            // oAuth verifier
            Log.d("Inside","inside");
            String verifier = uri
                    .getQueryParameter(URL_TWITTER_OAUTH_VERIFIER);

            try {
                // Get the access token
                AccessToken accessToken = twitter.getOAuthAccessToken(
                        requestToken, verifier);

                // Shared Preferences
                Editor e = mSharedPreferences.edit();

                // After getting access token, access token secret
                // store them in application preferences
                e.putString(PREF_KEY_OAUTH_TOKEN, accessToken.getToken());
                e.putString(PREF_KEY_OAUTH_SECRET,
                        accessToken.getTokenSecret());
                // Store login status - true
                e.putBoolean(PREF_KEY_TWITTER_LOGIN, true);
                e.commit(); // save changes

                Log.e("Twitter OAuth Token", "> " + accessToken.getToken());

                // For now i am getting his name only
                long userID = accessToken.getUserId();
                User user = twitter.showUser(userID);
                String username = user.getName();
                Log.d("usrnm",username);
                // Displaying in xml ui

            } catch (Exception e) {
                // Check log for login errors
                Log.e("Twitter Login Error", "> " + e.getMessage());
            }
        }




private void loginToTwitter() {
        Log.d("user",""+isTwitterLoggedInAlready());
        // Check if already logged in
        if (!isTwitterLoggedInAlready()) {
            ConfigurationBuilder builder = new ConfigurationBuilder();
            builder.setOAuthConsumerKey(TWITTER_CONSUMER_KEY);
            builder.setOAuthConsumerSecret(TWITTER_CONSUMER_SECRET);
            Configuration configuration = builder.build();

            TwitterFactory factory = new TwitterFactory(configuration);
            twitter = factory.getInstance();

            try {
                requestToken = twitter
                        .getOAuthRequestToken(TWITTER_CALLBACK_URL);
                this.startActivity(new Intent(Intent.ACTION_VIEW, Uri
                        .parse(requestToken.getAuthenticationURL())));
            } catch (TwitterException e) {
                e.printStackTrace();
            } 
        } else {
            // user already logged into twitter    
            new updateTwitterStatus().execute("Hello");

        }
    }
stack trace

04-12 11:21:52.479: E/Twitter Login Error(1065): > null

来源：https://stackoverflow.com/questions/15964408/exception-while-trying-to-tweet-using-twitter4j