Update reference doc after WebClient changes

Issue: SPR-14827

src/asciidoc/web-reactive.adoc

@@ -115,38 +115,29 @@ implies a synchronous, non-blocking controller method.
 
 Spring Framework 5 adds a new reactive `WebClient` in addition to the existing `RestTemplate`.
 
-Each supported HTTP client (e.g. Reactor Netty) is adapted to a set of shared,
+A `WebClient` instance use a `ClientHttpConnector` implementation to drive the underlying
+supported HTTP client (e.g. Reactor Netty). This client is adapted to a set of shared,
 reactive `ClientHttpRequest` and `ClientHttpResponse` abstractions that expose the request
 and response body as `Flux<DataBuffer>` with full backpressure support on the read and
-the write side. The `Encoder` and `Decoder` abstractions from `spring-core` are also used on
+the write side. The `HttpMessageReader` and `HttpMessageWriter` abstractions are also used on
 the client side for the serialization of a `Flux` of bytes to and from typed objects.
 
 An example of using the `WebClient`:
 
 [source,java,indent=0]
 [subs="verbatim,quotes"]
 ----
-ClientHttpConnector httpConnector = new ReactorClientHttpConnector();
-WebClient webClient = new WebClient(httpConnector);
+// create an immutable instance of WebClient
+WebClient webClient = WebClient.create(new ReactorClientHttpConnector());
 
-Mono<Account> response = webClient
-        .perform(get("http://example.com/accounts/1").accept(APPLICATION_JSON))
-        .extract(body(Account.class));
-----
-
-The above assumes static method imports from `ClientWebRequestBuilders` and `ResponseExtractors`
-that enable a fluent syntax. The same can also be done with RxJava using static imports from
-`RxJava1ClientWebRequestBuilder` and `RxJava1ResponseExtractors` instead:
+ClientRequest<Void> request = ClientRequest.GET("http://example.com/accounts/{id}", 1L)
+				.accept(MediaType.APPLICATION_JSON).build();
 
-[source,java,indent=0]
-[subs="verbatim,quotes"]
-----
-Single<Account> response = webClient
-        .perform(get("http://example.com/accounts/1").accept(APPLICATION_JSON))
-        .extract(body(Account.class));
+Mono<Account> account = this.webClient
+				.exchange(request)
+				.then(response -> response.body(toMono(Account.class)));
 ----
 
-
 [[web-reactive-getting-started]]
 == Getting Started