Prior to this commit, HTTP server observations for Spring WebFlux could
be recorded twice for a single request in some cases. The "COMPLETE" and
"CANCEL" signals would race in the reactive pipeline and would trigger
both the `doOnComplete()` and ` `doOnCancel()` operators, each calling
`observation.stop()` on the current observation.
This would in fact publish two different observations for the same
request.
This commit ensures that the instrumentation uses the `Mono#tap`
operator to guard against this case and only call `Observation#stop`
once for each request.
Fixes gh-31417
Prior to this commit, a cancelled exchange would always result in an
`"status":"UNKNOWN"` KeyValue. This only applied to reactive variants,
as cancelled exchanges are not currently detected for Servlet
implementations.
In some cases, exchanges can be cancelled by clients before they are
completed, but the response was actually received by the client. The
response status information has been set by the application and the
response has been committed. For those cases, we shouldn't assume an
"UNKNOWN" value.
This commit assumes that committed responses have a response status set
by the application and that the observations should reflect that. From
now on, we only assume an "UNKNOWN" status if the response has not been
commited.
Fixes gh-31388
This commit refines CORS wildcard processing Javadoc to
provides more details on how wildcards are handled for
Access-Control-Allow-Methods, Access-Control-Allow-Headers
and Access-Control-Expose-Headers CORS headers.
For Access-Control-Expose-Headers, it is not possible to copy
the response headers which are not available at the point
when the CorsProcessor is invoked. Since all the major browsers
seem to support wildcard including on requests with credentials,
and since this is ultimately the user-agent responsibility to
check on client-side what is authorized or not, Spring Framework
continues to support this use case.
See gh-31143
When the content length is known, use readNBytes on the InputStream in
StringHttpMessageConverter, which avoids some extra copying and allocations.
Closes gh-30942
This commit updates WebMVC converters and WebFlux
encoders/decoders to support custom serializers
with Kotlin Serialization when specified via
a custom SerialFormat.
It also turns the serializers cache to a non-static
field in order to allow per converter/encoder/decoder
configuration.
Closes gh-30870
This commit improves the documentation for the
`ShallowEtagHeaderFilter`, stating that it is only meant to support a
subset of conditional HTTP requests: GET requests with "If-None-Match"
headers. Other headers and state changing HTTP methods are not supported
here, as the filter only operates on the content of the response and has
no knowledge of the resource being served.
Closes gh-30517
This commits changes the return type from Publisher<?> to
Object in order to avoid potential compatibility issues when
the Reactive Streams dependency is not in the classpath.
Closes gh-30716
This commit ensures that any storage used for multipart handling only
gets cleaned up if multipart data is actually retrieved via
ServerWebExchange::getMultipartData.
Closes gh-30590
