Spring WebFlux and CalDav HTTP methods - spring-webflux

Question

I want to create a react-spring (with Netty underhood) proxy that can handle CalDav HTTP methods like REPORT.
If I use the ProxyExchange object in the controller it doesn't understand the REPORT method and I get an NPE when using the proxy.forward() method.
How can I teach webflux to understand REPORT?
My controller code:
#Controller
public class RestController {
#RequestMapping(value = "/")
public Mono<ResponseEntity<byte[]>> proxy(ProxyExchange<byte[]> proxy, ServerHttpRequest request) {
UriComponents uriComponents = UriComponentsBuilder
.fromHttpUrl("https://myhost.com")
.path(request.getPath().value())
.queryParams(request.getQueryParams())
.build();
return proxy
.sensitive(HttpHeaders.HOST)
.uri(uriComponents.toUri().toASCIIString())
.forward();
}
}

Answer 1

I found solution.
You need redefine several spring webflux classes.
You should create this package structure in YOUR project:
java/org/springframework/cloud/gateway/webflux
java/org/springframework/http
Than redefine standard spring ProxyExchange class (just copy class to "java/org/springframework/cloud/gateway/webflux"). Add this code to standard calss:
public Mono<ResponseEntity<T>> report() {
RequestEntity<Object> requestEntity = headers(RequestEntity.report(uri)).body(body());
return exchange(requestEntity);
}
public <S> Mono<ResponseEntity<S>> report(Function<ResponseEntity<T>, ResponseEntity<S>> converter) {
return report().map(converter::apply);
}
public Mono<ResponseEntity<T>> forward() {
switch (httpMethod) {
case GET:
return get();
case HEAD:
return head();
case OPTIONS:
return options();
case POST:
return post();
case DELETE:
return delete();
case PUT:
return put();
case PATCH:
return patch();
case REPORT:
return report();
default:
return Mono.empty();
}
}
public <S> Mono<ResponseEntity<S>> forward(Function<ResponseEntity<T>, ResponseEntity<S>> converter) {
switch (httpMethod) {
case GET:
return get(converter);
case HEAD:
return head(converter);
case OPTIONS:
return options(converter);
case POST:
return post(converter);
case DELETE:
return delete(converter);
case PUT:
return put(converter);
case PATCH:
return patch(converter);
case REPORT:
return report(converter);
default:
return Mono.empty();
}
}
Then redefine standard spring HttpMethod class (add code below) in "java/org/springframework/http":
public enum HttpMethod {
GET, HEAD, POST, PUT, PATCH, DELETE, OPTIONS, TRACE, REPORT;
And then redefine standard spring RequestEntity class (add code below) in "java/org/springframework/http":
/**
* Create an HTTP REPORT builder with the given url.
*
* #param url the URL
* #return the created builder
*/
public static BodyBuilder report(URI url) {
return method(HttpMethod.REPORT, url);
}
/**
* Create an HTTP REPORT builder with the given string base uri template.
*
* #param uriTemplate the uri template to use
* #param uriVariables variables to expand the URI template with
* #return the created builder
* #since 5.3
*/
public static BodyBuilder report(String uriTemplate, Object... uriVariables) {
return method(HttpMethod.REPORT, uriTemplate, uriVariables);
}