Use of Flux.just is problematic in that if the Flux is cancelled before
demand, the item may never be read, nor freed. Flux#just does not
even delegate cancellation signals.

Closes gh-22731

Closes gh-22731

Prior to this commit, the pattern destination variables were not set in
the message headers prior to calling the handler. In this case, the
`DestinationVariableMethodArgumentResolver` could not get the
destination variables from the message headers and resolve those as
handler arguments.

This commit mutates the message headers if the message destination
contains patterns.

Fixes gh-22776

Closes gh-22459

An empty path mapping in an @RequestMapping now consistently matches to
empty paths regardless of whether there are both type and method level,
annotations, or method-level only.

Closes gh-22543

See gh-22543

Closes gh-22777

Closes gh-22510

This commit moves the WebFlux getMappingPathPatterns() implementation
from RequestMappingHandlerMapping to
RequestMappingInfoHandlerMapping so that subclasses of the latter no
longer need to re-implement the method.

See gh-22543

See gh-22738

1) Tests use a timeout to avoid hanging issues
2) Some tests adjusted to work around potential rsocket-java issue
https://github.com/rsocket/rsocket-java/issues/613

See gh-22742

Closes gh22768

This commit configures the Kotlin plugin for Eclipse in the
spring-core-coroutines Gradle project so that users no longer have to
manually "Configure Kotlin / Add Kotlin Nature" within the Eclipse IDE
after importing projects.

This change is currently limited to the spring-core-coroutines project
since it is the only project in which Java code depends on compiled
Kotlin code; however, this change may later be applied to additional
projects if desirable.

Due to the changes in a7425c81, we no
longer need to execute tests using the JMXMP protocol in PERFORMANCE
builds.

This commit removes the JMXMP constant from the TestGroup enum and
updates affected tests, thereby effectively including such tests in
the standard build from now on.

See gh-22757

Closes gh-22766

This commit brings back the support for registration of multiple
Jackson modules with a null typeId.

Closes gh-22740

Closes gh-22761

Includes direct reflective introspection of annotations when possible.

Closes gh-22750

This commit introduces a publishEvent() method in the TestContext API
as a convenience for publishing an ApplicationEvent to the test's
ApplicationContext but only if the ApplicationContext is currently
available and with lazy creation of the ApplicationEvent.

For example, the beforeTestClass() method in
EventPublishingTestExecutionListener is now implemented as follows.

  public void beforeTestClass(TestContext testContext) {
      testContext.publishEvent(BeforeTestClassEvent::new);
  }

Closes gh-22765

Although the jmxremote_optional JAR has been added to the build agents
on the Bamboo CI server for the latest JDK 8 installation, that
solution is brittle since it has to be manually installed in every new
JDK installation. In addition, this approach will not work with JDK 9+
since the "Extension Mechanism" has been removed beginning with JDK 9.

https://docs.oracle.com/javase/10/migrate/toc.htm#JSMIG-GUID-2C896CA8-927C-4381-A737-B1D81D964B7B

This commit addresses this issue by adding the following dependency to
spring-context.

// Substitute for "javax.management:jmxremote_optional:1.0.1_04" which
// is not available on Maven Central
testRuntime("org.glassfish.external:opendmk_jmxremote_optional_jar:1.0-b01-ea")

With this change, the Spring PERFORMANCE builds now execute on JDK 8,
9, and 11.

See gh-22757

See gh-22308