如何根据反应堆上下文更改 url webClient

Question

Based on a country already added on a webfilter, I need to modify the request to a different server.

I already added the context with the webfilter to the chain, I can see it here, but I didn't find how to modify the received clientRequest based on the signal context on the chain. If anybody already found a way to do that and can help:

return webClient
                .filter(
                        ExchangeFilterFunction
                                .ofRequestProcessor(
                                        new Function<ClientRequest, Mono<ClientRequest>>() {
                                            @Override
                                            public Mono<ClientRequest> apply(ClientRequest clientRequest) {
                                                return Mono.just(
                                                        ClientRequest.from(clientRequest).build())
                                                        .doOnEach(new Consumer<Signal<ClientRequest>>() {
                                                            @Override
                                                            public void accept(Signal<ClientRequest> signal) {
                                                                var countryContext = signal.getContext()
                                                                        .getOrEmpty(CountryContext.COUNTRY_CONTEXT_HEADER_REST).get();
                                                                System.out.println(countryContext);
                                                            }
                                                        });
                                            }
                                        }
                                )
                ).build();

Answer 1

I found out a way, it's implementing a custom ExchangeFilterFunction , and using Mono.subscriberContext()

WebClient
    .filter((request, next) -> Mono.subscriberContext()
            .flatMap(ctx -> {
                        ClientRequest cr = ClientRequest.from(request)
                                // manipulate request to the new prefix server
                                // from the ctx signal.
                                .build();
                        return next.exchange(cr);
                    }
                ))

Answer 2

Mono.subscriberContext() is deprecated and will be removed in Spring Reactor 3.5. Use Mono.deferContextual() instead.

In your case:

WebClient.filter((request, next) -> 
  Mono.deferContextual(ctx -> {
    ClientRequest cr = ClientRequest.from(request)
    // manipulate request to the new prefix server
    // from the ctx signal.
    .build();
    return next.exchange(cr);
  })
);