Add default filters to routes create by route DSL

Hi

I define a route using API don't support for default filter.

this is my code

@Bean
public RouteLocator hiServerRouteLocator(RouteLocatorBuilder builder) {
    return builder.routes()
            .route("hi-server", r -> r.path("/hi-server/**")
                    .filters(f -> f.rewritePath("/hi-server/(?<remaining>.*)", "/${remaining}")
                    ).uri("lb://hi"))
            .build();
}

define a default filter in configure file

spring:
  application:
    name: gateway
  cloud:
    gateway:
      default-filters: 
      - name: AddResponseHeader
        args:
          name: X-Response-Default-Foo
          value: Default-Bar

access the url http://localhost:9999/hi/hi

HTTP/1.1 200 OK
Content-Length: 3
Content-Type: text/plain;charset=UTF-8
Date: Mon, 02 Apr 2018 02:11:13 GMT
X-Response-Default-Foo: Default-Bar  # default filter is work

hi!

access the url http://localhost:9999/hi-server/hi

HTTP/1.1 200 OK
Content-Length: 3
Content-Type: text/plain;charset=UTF-8
Date: Mon, 02 Apr 2018 02:12:39 GMT

# default filter don't work

hi!

Java routes API don't support for default filters or how to do it ?

The spring cloud gateway version is 2.0.0.M9

Start by reviewing the Java RouteLocatorBuilder example and the YAML default-filters configuration in the issue, then inspect closed pull request #2124 for prior work. Reproduce the contrasting requests to /hi/hi and /hi-server/hi and verify whether the configured response header is applied to routes created through the DSL.