How to get contents of a file stored in document library

Hi All,

I have created a sharepoint hosted app which is used to get the contents of a paticular file from the document library.

Below is the snippet:

$.ajax({url: <realative url of the file>,method:  "Get"}).done(successHandler)
.fail(errorHandler);

It always return status code : 0. Could anyone please let me know the what I am missing.

I am refering the following url to achieve this functionality:

http://www.c-sharpcorner.com/UploadFile/0e18a8/read-a-file-in-a-document-library-in-sharepoint-2013-using-c/

but some how its not working.

Thanks in advance.

Regards

AK