Classes for RESTful Webservices without connectors

Hi Experts,

We are trying to integrate SAP with a 3rd party system. They are only capable of handling REST webservices and that too without any connectors or middleware in between. For example the scenario would like below

Creation/Change of material via MM01/MM02 the webservices would trigger and the data has to be sent to 3rd party system as XML.

I have the below questions:

1) How can i trigger the rest webservice automatically when we change/create any material in SAP.

2) Do we have any class similar to CL_TREX_JSON_SERIALIZER which is used to deal with JSON and SAP?

Awaiting your response.

Thanks,

Siva.A