parse4j cannot return object value when it is already exists

Question

I am using parse4j to work with Parse.com

I am doing a loop to retrieve all data from the server at startup....

Apart from my code is :

ParseObject lastObj = subList.get(subList.size() - 1);
System.out.println(new Gson().toJson(lastObj));
System.out.println("createAt: " + lastObj.get("createdAt"));

And the result is:

{"objectId":"l2ncgKp0SG","className":"URLMapping","endPoint":"classes/URLMapping","isDirty":false,"data":{"shortUrl":"ilx","owner_id":"5e32a370-4d8f-4032-ad2d-d0a31aff5c77","originalUrl":"http://google.com","ip":"10.226.123.45"},"operations":{},"dirtyKeys":[],"updatedAt":"May 5, 2014 9:02:59 AM","createdAt":"May 5, 2014 9:02:59 AM"}
createAt: null

So, How the object value exists, but parse4j says it is null?

Answer 1

For build-in fields, One should use methods such as createdAt() ... objectId(), as getXXX is not working with built-in fields.