Jersey Rest Api for 6.2 version

I am trying to set up a grails application with Jesey RESTBuilder plugin

RequestBuilder rest = new RequestBuilder() def resp = rest.post("http://localhost:8181/bonita/loginservice?username=TestUser&password=bpm...") println("resp ******* " + resp)

// resp prints nothing here.

and then when I do below.

resp = rest.get { uri = "http://localhost:8181/bonita/API/identity/user/303/" }

I get Status 401 received. HttpUnauthorizedException. I believe, login did not work.

Any thoughts?