Closes gh-22504

Closes gh-22409

Closes gh-22426

Closes gh-22405

Closes gh-22359

Fixes #22254

This allows for proper nested type conversion in @Value Optional fields analogous to method parameters, through a new TypeDescriptor-based method in the TypeConverter SPI. As an additional and less involved measure that is worth backporting, DefaultListableBeanFactory defensively checks for pre-converted Optional wrappers.

Issue: SPR-17607

String.indexOf() expressions can be replaced with a call to the String.contains() method available in Java 5 and newer.

ResolvableType-based matching consistently respects generic factory method return type (even for pre-initialized raw singleton instance)

Issue: SPR-17524

Issue: SPR-17500

Closes gh-2019

See gh-2019

Issue: SPR-17374

Issue: SPR-16391

Issue: SPR-17374

Issue: SPR-17358
Issue: SPR-8891

Issue: SPR-17358

Previously, if a DeferredImportSelector was identified at a later stage
as part of processing the collected set of deferred imports, such
selector was processed as a regular import selector.

Semantically, it makes sense as we already are in the deferred phase at
this point and it doesn't make much sense to bother about the extra
contract.

However, Spring Framework 5 introduced the notion of Group that a
deferred import selector can define. When it does, the container has to
honour the contract of the Group rather than calling the simpler
ImportSelector parent contract.

This commit restructures the processing of such case. When a deferred
import selector is detected while processing deferred import selectors,
a group is created with only that selector and the group API is invoked.

Issue: SPR-17351

Includes consistent upfront resolution of factory method annotations.

Issue: SPR-8891

Support for Kotlin primary constructor and non-default public constructors in addition to default instantiation, aligned with AnnotationConfigApplicationContext and model attribute processing.

Issue: SPR-17292

Issue: SPR-16839

Issue: SPR-17273

Includes fallback match for collection/map dependency if qualified.

Issue: SPR-17272
Issue: SPR-17197

Issue: SPR-16839

This commit introduces a dependency on the Awaitility assertion
framework and makes use of asynchronous assertions in order to make
tests for asynchronous events more robust.

Issue: SPR-17211

Issue: SPR-17160

Includes caching of declared annotation arrays and combined searching for several annotation types (used in SpringCacheAnnotationParser).

Issue: SPR-16933

ScheduledAnnotationBeanPostProcessor also ignores TaskScheduler and ScheduledExecutorService, avoiding unnecessary annotation introspection on framework classes.

Issue: SPR-17166
Issue: SPR-16933

Issue: SPR-16858