Retrieving POST parameters from injected HttpServletRequest in a JAX-RS resources in JBoss EAP return null

Issue

I have a JAX-RS resource deployed into JBoss EAP and I inject the HttpServletRequest in order to retrieve the POST parameters from it. However, the attempt to retrieve it always results in null values. My code is as follows:

        @POST
        public void doPostTest(@Context final HttpServletRequest request){
            ...
        }               

How to fix that?