This commit handles "empty" cases for `ResponseEntity` controller
handler return types when wrapped with a `java.util.Optional` in Spring
MVC or a single `Publisher` like `Mono`.
Given the following example for Spring MVC:
```
@GetMapping("/user")
public Optional<ResponseEntity<User>> fetchUser() {
Optional<User> user = //...
return user.map(ResponseEntity::ok);
}
```
If the resulting `Optional` is empty, Spring MVC will infer a
`ResponseEntity` with an empty body and a 404 HTTP response status.
The same reasoning is applied to Spring WebFlux with Publisher types:
```
@GetMapping("/user")
public Mono<ResponseEntity<User>> fetchUser() {
Mono<User> user = //...
return user.map(ResponseEntity::ok);
}
```
This feature is only valid for `HttpEntity` return types and does not
apply to `@ResponseBody` controller handlers.
Issue: SPR-13281
This commit allows to specify a custom CorsConfigurationSource
in AbstractHandlerMapping (both Servlet and Reactive variants).
AbstractHandlerMapping#getCorsConfigurations method is now
deprecated.
Issue: SPR-17067
1. Update ExchangeFilterFunctions to delegate internally to
HttpHeaders.setBasicAuth(user, password).
2. Remove deprecation from
ExchangeFilterFunctions.basicAuthentication(String user, String password)
It is still useful as a filter to insert the header.
3. Update deprecation notes.
Issue: SPR-17099
Forwarded headers are now processed before ServerWebExchange is created
through ForwardedHeaderTransformer which has the same logic as the
ForwardedHeaderFilter but works on the request only.
ForwardedHeaderFilter is deprecated as of 5.1 but if registered it is
removed from the list of filters and ForwardedHeaderTransformer is used
instead.
Issue: SPR-17072
Empty Maps are preferably initialized without capacity (not initializing them at all or lazily initializing with default capacity when needed).
Issue: SPR-17105
This commit introduces Protobuf support in WebFlux via dedicated
codecs.
Flux<Message> are serialized/deserialized using delimited Protobuf
messages with the size of each message specified before the message
itself. In that case, a "delimited=true" parameter is added to the
content type.
Mono<Message> are expected to use regular Protobuf message
format (without the size prepended before the message).
Related HttpMessageReader/Writer are automatically registered when the
"com.google.protobuf:protobuf-java" library is detected in the classpath,
and can be customized easily if needed via CodecConfigurer, for example
to specify protocol extensions via the ExtensionRegistry based
constructors.
Both "application/x-protobuf" and "application/octet-stream" mime types
are supported.
Issue: SPR-15776
Prior to this commit, controller handlers (regular and exception
handlers as well) would not overwrite existing HTTP response headers on
the exchange. This would lead to situations where Content-Type values
set during the initial handling phase would not be overwritten when
handling an error later on.
This commit aligns the implementation of that result handler on the
Spring MVC one in that regard.
Issue: SPR-17082
Prior to this commit, the `DefaultClientResponse` implementation would
handle HTTP client cases where the server response body would need to be
consumed (pooled resources need to be released) and the body publisher
cancelled right away. This is done to avoid reading the whole response
body and returning the connection to the pool, now that this connection
cannot be reused.
This was done already when the `WebClient` is asked for a `Void` type
for the response body.
SPR-17054 brought a new case for that: whenever no message reader is
able to decode the response body, an `UnsupportedMediaTypeException`
error signal is sent. Prior to this commit, the response body would not
be consumed and cancelled for that case.
This commit refactors all those cases from the `DefaultClientResponse`
directly into the `BodyExtractors`, since most of the logic and
knowledge for that belongs there. We only need to only apply this
behavior when the HTTP client is involved, as the server does not want
this to happen.
Issue: SPR-17054
Given "/{foo}" and "/a=42;c=b", previously that would be treated as a
sequence of matrix vars with an empty path variable. After the change
the path variable "foo" is "a=42".
This should be ok for backawards compatibility since it's unlikely for
anything to rely on an empty path variable.
Issue: SPR-11897
Leverage https://github.com/jetty-project/jetty-reactive-httpclient
to add support for Jetty in WebClient via JettyClientHttpConnector.
Implemented with buffer copy instead of optimized buffer wrapping
because the latter hangs since Callback#succeeded doesn't allow
releasing the buffer and requesting more data at different times
(required for Mono<DataBuffer> for example).
See https://github.com/eclipse/jetty.project/issues/2429.
Issue: SPR-15092
Prior to this commit, resolving an argument for a WebFlux controller
that's missing from the request and not required by the handler would
throw a NullPointerException in some cases.
This involves the conversion of the parameter (a `String` parameter type
might not trigger this behavior) and sending a `null` within a reactive
stream, which is illegal per the RS spec.
We now rely on a `Mono.justOrEmpty()` to handle those specific cases.
Issue: SPR-17050
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
Brian Clozel
Juergen Hoeller
Sam Brannen
Rossen Stoyanchev
Sebastien Deleuze
stsypanov
xiexed
Arjen Poutsma