@Provider
@CreateRegistryFileResponse
public class CreateRegistryFileInterceptor implements WriterInterceptor {
    
    private static final Logger logger = Logger.getLogger("Employees");
    
    
    @Override
    public void aroundWriteTo(WriterInterceptorContext context) throws IOException, WebApplicationException {
        OutputStream stream = context.getOutputStream();
        ByteArrayOutputStream baos = (ByteArrayOutputStream) stream;
        byte[] bytes = baos.toByteArray();
        String fileContent = new String(bytes);
        logger.debug("Interceptor:");
        logger.debug(fileContent);
        context.setOutputStream(stream);
        context.proceed();
    }
}

@NameBinding
@Retention(RUNTIME)
@Target({TYPE, METHOD})
public @interface CreateRegistryFileResponse {
}

@POST
@CreateRegistryFileResponse
@Path("/file")
@Consumes({MediaType.APPLICATION_JSON})
public Response createRegistryFile(@HeaderParam("Authorization") String token, RegistryParams registryParams) {
    File file = getBean().createFile(registryParams);
    return Response.ok(file, MediaType.APPLICATION_OCTET_STREAM).header("content-disposition","attachment; filename =file.getName()).build();
    }

@ApplicationPath("/")
public class RestApp extends Application {

    @Override
    public Set<Class<?>> getClasses() {
        Set<Class<?>> classes = new HashSet<Class<?>>();
        classes.add(RestApi.class);
        classes.add(CreateRegistryFileInterceptor.class);
        return classes;
    }
}