"Approve" / or "Reject" Workitem via email notification

I have a client has below enquiry:
We want to "approve" / or "reject" Workitem without open Workitem.

By adding "Approve" or "Reject" button in body of the email. when user get Email notification, user can click the button to "approve" / or "reject" Workitem without open Workitem.
We need to build custom application that read Email and check Workitem number, sender name and the body of email.
This Custom Application will integrate to RTC to Update Approval WI.

Is it possible to update work item Approval via plain Java API or OSLC?

Thank you very much