If Stament returns null

Question

Firts codes works well.. But second codes gives error as: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference

Working Code:

String dnt = model.getDonut;
     if (dnt != null) {
            if (!dnt.equals("")) {
      //Do sth
                }
            }

Not Working Code:

String dnt = model.getDonut;
     if (dnt != null || !dnt.equals("")) {
      //Do sth
            }