public void onDataChange(DataSnapshot snapshot) //Log.e("Data Change", snapshot.getValuepublic void onDataChange(DataSnapshot dataSnapshot) User u = dataSnapshot.getValue(User.classjava.lang.NullPointerException:
我在NotificationsListener上传递的用户不是null。to invoke virtual method 'java.lang.String com.example.videomeeting.models.User.getUserName()' on a nullto invoke virtual method 'java.lang.String com.example.videomeeting.models.User.getUserName()' on a nullpublic vo