After every disk write or every 0.5 seconds, whichever is later
After the file download is complete
This method should return true to cancel the transfer or return false to continue.
Usually, the cancel request will be accepted by UltraLiteJ. This will result in a ULjException being thrown with the errorCode
set to ULjException.SQLE_INTERRUPTED. However, if the download has been completed for BlackBerry object store, UltraLiteJ
will not cancel the transfer.