LoginActivity.java

import java.util.Arrays;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;

import com.facebook.Request;
import com.facebook.Response;
import com.facebook.Session;
import com.facebook.SessionState;
import com.facebook.UiLifecycleHelper;
import com.facebook.model.GraphUser;
import com.facebook.widget.LoginButton;

public class LoginActivity extends Activity {
  private UiLifecycleHelper uiHelper;
    private Session.StatusCallback callback = new Session.StatusCallback() {
        @Override
        public void call(Session session, SessionState state, Exception exception) {
            onSessionStateChange(session, state, exception);
        }
    };

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_login);
		
        uiHelper = new UiLifecycleHelper(this, callback);
        uiHelper.onCreate(savedInstanceState);
        
        LoginButton button = (LoginButton) findViewById(R.id.btnFacebookLogin);
        button.setReadPermissions(Arrays.asList("basic_info","email"));
	}

    private void onSessionStateChange(Session session, SessionState state, Exception exception) {
    	if (session != null && session.isOpened()) {
    		Log.d("DEBUG", "facebook session is open ");
    		// make request to the /me API
            Request.executeMeRequestAsync(session, new Request.GraphUserCallback() {
                // callback after Graph API response with user object
                @Override
                public void onCompleted(GraphUser user, Response response) {
                	if (user != null) {
                		Log.d("DEBUG", "email: " + user.asMap().get("email").toString());
                	}
                }
            });
    	}
    }
    
	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.login, menu);
		return true;
	}

    @Override
    public void onResume() {
        super.onResume();
        uiHelper.onResume();
    }

    @Override
    public void onPause() {
        super.onPause();
        uiHelper.onPause();
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        uiHelper.onActivityResult(requestCode, resultCode, data);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        uiHelper.onDestroy();
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        uiHelper.onSaveInstanceState(outState);
    }
}