How to get Subject (user) from jaxrs context

[XiLai Dai]

Hi,

We have a REST service impl class and just want to get the authentication user 
info from the impl of one operation, it looks like:

public class FlowManagementServiceImpl implements FlowManagementService {
    @Context
private org.apache.cxf.jaxrs.ext.MessageContext mc;

    @GET
    @Path("/deploy/{flowName}/{flowVersion}")
    @Produces("text/plain")
    public Response deployFlow(@PathParam("flowName") String flowName,
            @PathParam("flowVersion") String flowVersion) {
    ......
    System.out.println("role: " + 
mc.getSecurityContext().getUserPrincipal().getName());
    ......
}
}

Seems only the principlal name can be retrieved from MessageContext, how to get 
the Subject (user) name from the operation? Thanks!
(CXF 2.7.10 used)

Thanks.
Xilai Dai