All fragments should have an empty constructor (i.e. a constructor method having no input arguments). Therefore, in order to pass your data to the Fragment being created, you should use the setArguments() method. This methods gets a bundle, which you store your data in, and stores the Bundle in the arguments. Subsequently, this Bundle can then be retrieved in onCreate() and onCreateView() call backs of the Fragment.

Activity:

Bundle bundle = new Bundle();
String myMessage = "Stack Overflow is cool!";
bundle.putString("message", myMessage );
FragmentClass fragInfo = new FragmentClass();
fragInfo.setArguments(bundle);
transaction.replace(R.id.fragment_single, fragInfo);
transaction.commit();

Fragment:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
   String myValue = this.getArguments().getString("message");
   ...
}