Spring Framework 5.2 introduced support for implementing the Ordered
interface in a @ControllerAdvice bean. This support requires that
@ControllerAdvice beans be eagerly resolved from the BeanFactory in
order to invoke the getOrder() method defined in the Ordered interface.
Unfortunately doing so resulted in a regression in that an attempt to
eagerly resolve a scoped @ControllerAdvice bean throws a
BeanCreationException due to the lack of an active scope (e.g., request
or session scope).

This commit fixes this regression by avoiding eager resolution of scoped
@ControllerAdvice beans. As a direct consequence, the Ordered interface
is not supported for scoped @ControllerAdvice beans.

Closes gh-23985

See gh-1956

Closes gh-23976

Closes gh-23409

Apply default Accept header for HttpUrlConnection only.

See gh-23855

Closes gh-23740

See gh-23939

See gh-23741

A ResponseStatus exception now exposes extra method to return headers
for the response. This is used in ResponseStatusExceptionHandler to
apply the headers to the response.

Closes gh-23741

Closes gh-23780

See gh-23803

See gh-23780

See gh-23764

Closes gh-23764

See gh-23638

If an error looks like a "disconnected client" but the response is not
yet committed then it can't be an I/O error from writing to the server
response. It is most likely as a result of a remote call as part of
request handling.

Not setting the response to 500 in this case results in a 200 response
status despite the error. Even if it was an I/O error from the server
response, setting the status won't impact a failed response.

Closes gh-23319

See gh-23539
Co-authored-by: NSam Brannen <sbrannen@pivotal.io>

Closes gh-23567

Closes: gh-23596

See gh-23539

Closes gh-23470

Closes gh-23490

Deprecate all mutation methods in `MethodParameter` in favor of factory
methods that return a new instance. Existing code that previously relied
on mutation has been updated to use the replacement methods.

Closes gh-23385

The isJavaIdentifier check is not really required, but also seems
intuitive for variables to be Java identifier-like. This commit relaxes
the constraint a bit by also allowing "-".

Closes gh-23101

To make the switching of separators complete, it is also important to
know whether the decoding of path segment values and the parsing of
path param should be done as those are applied transparently.

This commit replaces the recently added separator argument to
PathContainer.parsePath with an Options type with two predefined
constants. One for HTTP URLs with automatic decoding and parsing of
path params, and another for "." separated message routes without
decoding except for encoded sequences of the separator itself.

See gh-23310

Replace docs on using MultipartBodyBuilder for the RestTemplate with
examples that show MultiValueMap. Originally the idea was to make
MultipartBodyBuilder accessible to the RestTemplate too, but with
support for async parts that's no longer a good fit.

Closes gh-23295

OncePerRequestFilter now has a doFilter method that allows separate
processing of nested ERROR dispatches. This is useful for filters
that wrap the request and response.

Closes gh-23196

See gh-23274

Revert to state before DefaultMultipartMessageReader