Android login and authenticate facebook user into a backendless mbaas application -

i have done upto code below , can succesfully authenticate , login facebook user.

i have compile 'com.backendless:backendless:3.0.15.1' in build gradle.

private facebookcallback<loginresult> mcallback = new facebookcallback<loginresult>() {     @override     public void onsuccess(loginresult loginresult) { //        mdialog.dismiss();          graphrequest request = graphrequest.newmerequest(                 loginresult.getaccesstoken(),                 new graphrequest.graphjsonobjectcallback() {                     @override                     public void oncompleted(jsonobject object, graphresponse response) {                         log.e("response: ", response + "");                          user = new user();                         user.facebookid = object.optstring("id");                         user.name = object.optstring("name");                         user.email = object.optstring("email");                         user.gender = object.optstring("gender");                         user.locale = object.optstring("locale");                          utils.setcurrentuser(user, loginactivity.this);                          startactivity(new intent(loginactivity.this, mainactivity.class));                         finish();                          toast.maketext(loginactivity.this, "logged in " + user.name, toast.length_long).show();                     }                 }         );          bundle parameters = new bundle();         parameters.putstring("fields", "id, name, email, gender, locale, birthday, picture.width(80).height(80)");         request.setparameters(parameters);         request.executeasync();     }      @override     public void oncancel() {         log.i(tag, "loginbutton facebookcallback oncancel");     }      @override     public void onerror(facebookexception error) {         log.i(tag, "loginbutton facebookcallback onerror:: "+error.getmessage());         log.i(tag, "exception:: "+error.getstacktrace());     } };