Question

public class FacebookConnect extends Activity {

    Facebook facebook = new Facebook("");
    String FILENAME = "AndroidSSO_data";
    private SharedPreferences mPrefs;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        /*
         * Get existing access_token if any
         */
        mPrefs = getPreferences(MODE_PRIVATE);
        String access_token = mPrefs.getString("access_token", null);
        long expires = mPrefs.getLong("access_expires", 0);
        if(access_token != null) {
            facebook.setAccessToken(access_token);
        }
        if(expires != 0) {
            facebook.setAccessExpires(expires);
        }

        /*
         * Only call authorize if the access_token has expired.
         */
        if(!facebook.isSessionValid()) {

            facebook.authorize(this, new String[] {}, new DialogListener() {
                public void onComplete(Bundle values) {
                    SharedPreferences.Editor editor = mPrefs.edit();
                    editor.putString("access_token", facebook.getAccessToken());
                    editor.putLong("access_expires", facebook.getAccessExpires());
                    editor.commit();
                }

                public void onFacebookError(FacebookError error) {}

                public void onError(DialogError e) {}

                public void onCancel() {}
            });
        }
    }

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

        facebook.authorizeCallback(requestCode, resultCode, data);
        AsyncFacebookRunner asyncRunner = new AsyncFacebookRunner(this.facebook);
        asyncRunner.request("me", new meRequestListener());
    }
}

That is my code to connect with FB to log in. I’ve two doubts with it:
1. How do I get the user info? (FB name)
2. How do I store it in the database. The problem here is that even if I allow an user to log in via facebook, there can be other users with the same name. So, does fb allow me to get their e-mail address for creating an unique entry in the database?

Answer 1

If you want unique identifier for user, use his facebook id. To get this – you can use graph API that is provided by FB. More info about this here: https://developers.facebook.com/docs/reference/api/
To get basic info (with facebook id) of currently logged user, you can use this api: https://graph.facebook.com/me (it works only, if user has valid access token.