How to access the "findById" method of a RESTful service through "getJSON"?

This is the following code of my RESTful service class:

@RequestScoped
@Path("/empresas")
public class EmpresaEndpoint {

    @Inject
    private EmpresaRB empresaRB;

    @GET
    @Path("/{id:[0-9][0-9]*}")
    @Produces("application/json")
    public Response findById(@PathParam("id") final Long id) {
        //TODO: retrieve the empresas
        Empresa empresas = null;
        if (empresas == null) {
            return Response.status(Status.NOT_FOUND).build();
        }
        return Response.ok(empresas).build();
    }

    @GET
    @Produces("application/json")
    public List<Empresa> listAll(
            @QueryParam("start") final Integer startPosition,
            @QueryParam("max") final Integer maxResult) {
        //TODO: retrieve the empresa
        return empresaRB.getEmpresas();
    }

}

If I wanted to access all the data stored on "Empresa" via jQuery, I would do:

$.getJSON( "rest/empresas", function( data ) {
  //whatever is needed.
}

The code above would access the "listAll" method. So how can I access the "findById" method and pass the necessary parameter?