Create
Fabric account and Twitter App
Step – 1 follow this link to create fabric account.  
Step – 2 follow this link to login after complete sign up process.  
Step – 3 Create New app in Twitter apps.
Step – 4 Go to application management and navigate Keys and Access Tokens.
Step – 5 Copy and Paste your consumer key and
secret key.
Step – 6 Now create new app in fabric studio.
Step – 7 Select Twitter from All Kits and install it
Step – 8 Paste here your consumer key and secret key from your app
which you copied and now you got code which set in your main activity.
Step – 9 Now put this Studio CODE if you don't directly get.
package com..testtwitterlogin;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
import com.twitter.sdk.android.Twitter;
import com.twitter.sdk.android.core.Callback;
import com.twitter.sdk.android.core.Result;
import com.twitter.sdk.android.core.TwitterAuthConfig;
import com.twitter.sdk.android.core.TwitterException;
import com.twitter.sdk.android.core.TwitterSession;
import com.twitter.sdk.android.core.identity.TwitterLoginButton;
import com.twitter.sdk.android.core.models.User;
import io.fabric.sdk.android.Fabric;
public class MainActivity extends Activity {
    private static final String TWITTER_KEY = "your twitter consumer key";
    private static final String TWITTER_SECRET = "your twitter secret key";
    private TwitterLoginButton loginButton;
   
TextView textView;
    TwitterSession session;
    @Override
    protected void onCreate(Bundle
savedInstanceState) {
        super.onCreate(savedInstanceState);
        TwitterAuthConfig authConfig = new TwitterAuthConfig(TWITTER_KEY,
TWITTER_SECRET);
        Fabric.with(this, new Twitter(authConfig));
        setContentView(R.layout.activity_main);
        textView =
(TextView) findViewById(R.id.tv_username);
        loginButton =
(TwitterLoginButton) findViewById(R.id.twitter_login_button);
        loginButton.setCallback(new Callback<TwitterSession>() {
            @Override
            public void success(Result<TwitterSession>
result) {
                session = result.data;
                String username = session.getUserName();
                Long 
userid = session.getUserId();
                textView.setText("Hi " +
username + "\n id:" + userid);
            }
            @Override
            public void failure(TwitterException
exception) {
                Log.d("TwitterKit",
"Login with Twitter failure", exception);
            }
        });
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
        super.onActivityResult(requestCode,
resultCode, data);
        loginButton.onActivityResult(requestCode,
resultCode, data);
    }
    void getUserData() {
        Twitter.getApiClient(session).getAccountService()
                .verifyCredentials(true, false, new Callback<User>() {
                    @Override
                    public void failure(TwitterException
e) {
                    }
                    @Override
                    public void success(Result<User>
userResult) {
                        User user =
userResult.data;
                        String twitterImage
= user.profileImageUrl;
                        try {
                            Log.e("imageurl",
user.profileImageUrl);
                            Log.e("name",
user.name);
                           // Log.e("email",user.email);
                            Log.e("des", user.description);
                            Log.e("followers ",
String.valueOf(user.followersCount));
                            Log.e("createdAt",
user.createdAt);
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                });
    }
}
 
Final Output
Feel free to post your comments, queries and suggestions 
Cheers...:-)