android twitter login using twitter4j

please use following code to login using twitter4j.
it is working fine
 


public class TweetToTwitterActivity extends Activity {
 
        private static final String TAG = "Blundell.TweetToTwitterActivity";
 
        /** Name to store the users access token */
        private static final String PREF_ACCESS_TOKEN = "accessToken";
        /** Name to store the users access token secret */
        private static final String PREF_ACCESS_TOKEN_SECRET = "accessTokenSecret";
        /** Consumer Key generated when you registered your app at https://dev.twitter.com/apps/ */
        private static final String CONSUMER_KEY = "yourConsumerKey";
        /** Consumer Secret generated when you registered your app at https://dev.twitter.com/apps/  */
        private static final String CONSUMER_SECRET = "yourConsumerSecret"; // XXX Encode in your app
        /** The url that Twitter will redirect to after a user log's in - this will be picked up by your app manifest and redirected into this activity */
        private static final String CALLBACK_URL = "tweet-to-twitter-blundell-01-android:///";
        /** Preferences to store a logged in users credentials */
        private SharedPreferences mPrefs;
        /** Twitter4j object */
        private Twitter mTwitter;
        /** The request token signifies the unique ID of the request you are sending to twitter  */
        private RequestToken mReqToken;
 
        private Button mLoginButton;
        private Button mTweetButton;
 
        /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                Log.i(TAG, "Loading TweetToTwitterActivity");
                setContentView(R.layout.main);
               
                // Create a new shared preference object to remember if the user has
                // already given us permission
                mPrefs = getSharedPreferences("twitterPrefs", MODE_PRIVATE);
                Log.i(TAG, "Got Preferences");
               
                // Load the twitter4j helper
                mTwitter = new TwitterFactory().getInstance();
                Log.i(TAG, "Got Twitter4j");
               
                // Tell twitter4j that we want to use it with our app
                mTwitter.setOAuthConsumer(CONSUMER_KEY, CONSUMER_SECRET);
                Log.i(TAG, "Inflated Twitter4j");
               
                mLoginButton = (Button) findViewById(R.id.login_button);
                mTweetButton = (Button) findViewById(R.id.tweet_button);
        }
 
        /**
         * Button clickables are declared in XML as this projects min SDK is 1.6</br> </br>
         * Checks if the user has given this app permission to use twitter
         * before</br> If so login and enable tweeting</br>
         * Otherwise redirect to Twitter for permission
         *
         * @param v the clicked button
         */
        public void buttonLogin(View v) {
                Log.i(TAG, "Login Pressed");
                if (mPrefs.contains(PREF_ACCESS_TOKEN)) {
                        Log.i(TAG, "Repeat User");
                        loginAuthorisedUser();
                } else {
                        Log.i(TAG, "New User");
                        loginNewUser();
                }
        }
 
        /**
         * Button clickables are declared in XML as this projects min SDK is 1.6</br> </br>
         *
         * @param v the clicked button
         */
        public void buttonTweet(View v) {
                Log.i(TAG, "Tweet Pressed");
                tweetMessage();
        }
 
        /**
         * Create a request that is sent to Twitter asking 'can our app have permission to use Twitter for this user'</br>
         * We are given back the {@link mReqToken}
         * that is a unique indetifier to this request</br>
         * The browser then pops up on the twitter website and the user logins in ( we never see this informaton
         * )</br> Twitter then redirects us to {@link CALLBACK_URL} if the login was a success</br>
         *
         */
        private void loginNewUser() {
                try {
                        Log.i(TAG, "Request App Authentication");
                        mReqToken = mTwitter.getOAuthRequestToken(CALLBACK_URL);
 
                        Log.i(TAG, "Starting Webview to login to twitter");
                        WebView twitterSite = new WebView(this);
                        twitterSite.loadUrl(mReqToken.getAuthenticationURL());
                        setContentView(twitterSite);
 
                } catch (TwitterException e) {
                        Toast.makeText(this, "Twitter Login error, try again later", Toast.LENGTH_SHORT).show();
                }
        }
 
        /**
         * The user had previously given our app permission to use Twitter</br>
         * Therefore we retrieve these credentials and fill out the Twitter4j helper
         */
        private void loginAuthorisedUser() {
                String token = mPrefs.getString(PREF_ACCESS_TOKEN, null);
                String secret = mPrefs.getString(PREF_ACCESS_TOKEN_SECRET, null);
 
                // Create the twitter access token from the credentials we got previously
                AccessToken at = new AccessToken(token, secret);
 
                mTwitter.setOAuthAccessToken(at);
               
                Toast.makeText(this, "Welcome back", Toast.LENGTH_SHORT).show();
               
                enableTweetButton();
        }
 
        /**
         * Catch when Twitter redirects back to our {@link CALLBACK_URL}</br>
         * We use onNewIntent as in our manifest we have singleInstance="true" if we did not the
         * getOAuthAccessToken() call would fail
         */
        @Override
        protected void onNewIntent(Intent intent) {
                super.onNewIntent(intent);
                Log.i(TAG, "New Intent Arrived");
                dealWithTwitterResponse(intent);
        }
 
        @Override
        protected void onResume() {
                super.onResume();
                Log.i(TAG, "Arrived at onResume");
        }
       
        /**
         * Twitter has sent us back into our app</br>
         * Within the intent it set back we have a 'key' we can use to authenticate the user
         *
         * @param intent
         */
        private void dealWithTwitterResponse(Intent intent) {
                Uri uri = intent.getData();
                if (uri != null && uri.toString().startsWith(CALLBACK_URL)) { // If the user has just logged in
                        String oauthVerifier = uri.getQueryParameter("oauth_verifier");
 
                        authoriseNewUser(oauthVerifier);
                }
        }
 
        /**
         * Create an access token for this new user</br>
         * Fill out the Twitter4j helper</br>
         * And save these credentials so we can log the user straight in next time
         *
         * @param oauthVerifier
         */
        private void authoriseNewUser(String oauthVerifier) {
                try {
                        AccessToken at = mTwitter.getOAuthAccessToken(mReqToken, oauthVerifier);
                        mTwitter.setOAuthAccessToken(at);
 
                        saveAccessToken(at);
 
                        // Set the content view back after we changed to a webview
                        setContentView(R.layout.main);
                       
                        enableTweetButton();
                } catch (TwitterException e) {
                        Toast.makeText(this, "Twitter auth error x01, try again later", Toast.LENGTH_SHORT).show();
                }
        }
 
        /**
         * Allow the user to Tweet
         */
        private void enableTweetButton() {
                Log.i(TAG, "User logged in - allowing to tweet");
                mLoginButton.setEnabled(false);
                mTweetButton.setEnabled(true);
        }
 
        /**
         * Send a tweet on your timeline, with a Toast msg for success or failure
         */
        private void tweetMessage() {
                try {
                        mTwitter.updateStatus("Test - Tweeting with @Blundell_apps #AndroidDev Tutorial using #Twitter4j http://blog.blundell-apps.com/sending-a-tweet");
 
                        Toast.makeText(this, "Tweet Successful!", Toast.LENGTH_SHORT).show();
                } catch (TwitterException e) {
                        Toast.makeText(this, "Tweet error, try again later", Toast.LENGTH_SHORT).show();
                }
        }
 
        private void saveAccessToken(AccessToken at) {
                String token = at.getToken();
                String secret = at.getTokenSecret();
                Editor editor = mPrefs.edit();
                editor.putString(PREF_ACCESS_TOKEN, token);
                editor.putString(PREF_ACCESS_TOKEN_SECRET, secret);
                editor.commit();
        }
}