Prior to this commit, `WebClient` would throw `IllegalArgumentException`
when receiving an HTTP response with an unknown HTTP status code.
This commit is a follow up of SPR-16748 (supporting non-standard HTTP
status codes on the reactive `ClientHttpResponse`), and is mirroring
SPR-15978 (supporting non-standard HTTP status codes in `RestTemplate`).
With this change, `WebClient` now tolerates unknown status codes in some
cases, while not offering that choice as a first class citizen:
`HttpStatus` is still the preferred way to deal with HTTP status codes.
Here's how `WebClient` will behave when fetching the full response:
```
// Given a remote endpoint returning a "123" HTTP status code
Mono<ClientResponse> result = this.webClient.get()
.uri("/status/123")
.exchange();
// will still throw an IllegalArgumentException
HttpStatus status = result.block().statusCode();
// is safe and will return 123
int statusCode = result.block().rawStatusCode();
```
Resolving directly the response body with `retrieve()` is different.
```
// will send an error signal with a UnknownHttpStatusCodeException
Mono<String> result = this.webClient.get()
.uri("/status/123")
.retrieve()
.bodyToMono(String.class);
```
In general, `WebClient` will provide high-level support
for well-known HTTP status codes, like error handling with
`WebClient.ResponseSpec#onStatus`.
For such support with unknown status codes, it is better to rely
on lower level constructs such as `ExchangeFilterFunction`.
Issue: SPR-16819
1. Use special category prefix "spring-web.reactivestreams" for logging
of reactive streams signals in spring-web, since those are quite
verbose would fill the logs at TRACE.
2. Add and use loggers in request and websocket session implementations
separate from reactive streams bridge for regular TRACE logging.
3. Improve log messages and add where missing (e.g. for Reactor)
Issue: SPR-16898
This commit introduces RouterFunctions.Builder, a new way to build
router functions that does not require static imports, thus being more
discoverable and convenient.
Issue: SPR-16953
Polish a few issue identified when adding checkstyle to the
build. Although checkstyle is not enforcing rules on tests,
these are a few minor changes that are still worth making.
Issue: SPR-16968
In SPR-16892, the `EncoderHttpMessageWriter` has been improved to write
`"Content-Length"` HTTP response headers if the response body is of type
`Mono` (i.e. the actual content length is easily accessible without
buffering a possibly large response body). That change was relying on
the fact that the server side is using a `ChannelSendOperator` to delay
the writing of the body until the first signal is received.
This strategy is not effective on the client side, since no such channel
operator is used for `WebClient`. This commit improves
`EncoderHttpMessageWriter` and delays, for `Mono` HTTP message bodies
only, the writing of the body so that we can write the
`"Content-Length"` header information once we've got the body resolved.
Issue: SPR-16949
The key in CachingResourceResolver now includes the "Accept-Encoding"
request header cleaned to exclude "*", "identity", and parameters, and
also sorted alphabetically.
For encoded resources the response now includes a response header with
"Vary: Accept-Encoding".
Issue: SPR-16381
The new EncodedResourceResolver is a generalized version of
GzipResourceResolver that can be configured to support different
content codings, by "br" and "gzip".
GzipResourceResolver is now deprecated.
Issue: SPR-16381
This commit makes it possible to pass attributes from the WebSession of
a handshake request to the WebSocketSession, by configuring a
Predicate<String> on HandshakeWebSocketService.
Issue: SPR-16212
This commit removes all places where forwarded headers are checked
implicitly, on an ad-hoc basis.
ForwardedHeaderFilter is expected to be used instead providing
centralized control over using or discarding such headers.
Issue: SPR-16668
This commit exposes the resource lookup function used by
`RouterFunctions.resources(String, Resource)`, so that it can be
composed upon.
Issue: SPR-16788
This commit introduces support for creating a new `ServerRequest` from
an existing instance. This is especially useful when filtering requests
in a HandlerFilterFunction.
Issue: SPR-16707
