Vraptor: Get Data Type no Interceptor

request.getContentType()

public void intercept(InterceptorStack stack, ResourceMethod method, Object resourceInstance) {
    	System.out.println("Interceptando " + request.getRequestURI());
    	
    	boolean authorized = false;
    	
    	...
    	
        if (userSession.isLogged()) {
        	if(authorized){
        		stack.next(method, resourceInstance);
        	}else{
        		result.redirectTo(LoginController.class).index();
        	}
        } else {
        	if (request.getContentType() != null && request.getContentType().contains("json") ){
        		result.use(Results.json()).withoutRoot().from(Resources.getMessage("user.not.logged")).serialize();
        		response.setStatus(Response.SC_BAD_REQUEST);
        	}else{
        		result.redirectTo(LoginController.class).login();
        	}
        }
    }