Prior to this commit, evaluating validation hints for
@javax.validation.Valid caused exceptions being raised when getting the
value of this annotation, which does not exist. Bypassing
AnnotationUtils.getValue() in those cases can improve performance by
avoiding the cost incurred by raising exceptions.

See gh-26787

MVC data class processor constructs target instance even in case of binding failure, as long as the corresponding method parameter is not marked as optional.

Closes gh-24372

Closes gh-24695

Closes gh-24107
Closes gh-22169
Closes gh-25265

This commit updates URLs to prefer the https protocol. Redirects are not followed to avoid accidentally expanding intentionally shortened URLs (i.e. if using a URL shortener).

# Fixed URLs

## Fixed Success
These URLs were switched to an https URL with a 2xx status. While the status was successful, your review is still recommended.

* [ ] http://www.apache.org/licenses/ with 1 occurrences migrated to:
  https://www.apache.org/licenses/ ([https](https://www.apache.org/licenses/) result 200).
* [ ] http://www.apache.org/licenses/LICENSE-2.0 with 6515 occurrences migrated to:
  https://www.apache.org/licenses/LICENSE-2.0 ([https](https://www.apache.org/licenses/LICENSE-2.0) result 200).

This commit updates URLs to prefer the https protocol. Redirects are not followed to avoid accidentally expanding intentionally shortened URLs (i.e. if using a URL shortener).

# Fixed URLs

## Fixed Success
These URLs were switched to an https URL with a 2xx status. While the status was successful, your review is still recommended.

* [ ] http://www.apache.org/licenses/ with 1 occurrences migrated to:
  https://www.apache.org/licenses/ ([https](https://www.apache.org/licenses/) result 200).
* [ ] http://www.apache.org/licenses/LICENSE-2.0 with 6625 occurrences migrated to:
  https://www.apache.org/licenses/LICENSE-2.0 ([https](https://www.apache.org/licenses/LICENSE-2.0) result 200).

Includes an extension of SmartValidator for candidate value validation, as well as nullability refinements in Validator and BindingResult.

Issue: SPR-16840
Issue: SPR-16841
Issue: SPR-16854

Also, TypeMismatchExceptions get registered via BindingErrorProcessor.

Issue: SPR-16449

Issue: SPR-16083

Includes unified detection of Kotlin's optional parameters in MethodParameter.isOptional(), reduces BeanUtils.findPrimaryConstructor to Kotlin semantics (for reuse in AutowiredAnnotationBeanPostProcessor), and finally introduces a common KotlinDetector delegate with an isKotlinType(Class) check.

Issue: SPR-15877
Issue: SPR-16020

Issue: SPR-15871

Issue: SPR-15869

Issue: SPR-15542

This commit updates BeanUtils class in order to add Kotlin optional
parameters with default values support to the immutable data classes
support introduced by SPR-15199.

Issue: SPR-15673

This commits extends nullability declarations to the field level, formalizing the interaction between methods and their underlying fields and therefore avoiding any nullability mismatch.

Issue: SPR-15720

Beyond just formally declaring the current behavior, this revision actually enforces non-null behavior in selected signatures now, not tolerating null values anymore when not explicitly documented. It also changes some utility methods with historic null-in/null-out tolerance towards enforced non-null return values, making them a proper citizen in non-null assignments.

Some issues are left as to-do: in particular a thorough revision of spring-test, and a few tests with unclear failures (ignored as "TODO: NULLABLE") to be sorted out in a follow-up commit.

Issue: SPR-15540

Includes a new overloaded ModelAndView constructor with an HttpStatus argument, as well as a HandlerMethodArgumentResolverSupport refactoring (revised checkParameterType signature, actually implementing the HandlerMethodArgumentResolver interface).

Issue: SPR-15199

This commit also fixes broken javadoc links and code references.

Issue: SPR-13188

Issue: SPR-13440

Issue: SPR-13402

The protected validation methods are analogous to ModelAttributeMethodProcessor now.

Issue: SPR-12655

Issue: SPR-12655

Issue: SPR-12406

Issue: SPR-12241

Issue: SPR-10130

This reverts commit 45fa5082, reversing
changes made to a312d900.

Issue: SPR-10130

An @RequestBody or an @RequestPart argument can now be followed by an
Errors/BindingResult argument making it possible to handle validation
errors (as a result of an @Valid annotation) locally within the
@RequestMapping method.

Issue: SPR-7114

The ErrorsMethodArgumentResolver expects the preceding @ModelAttribute
in the controller method signature to be the last one added in the
model -- an assumption that can break if a model attribute is added
earlier (e.g. through a @ModelAttribute method) and more attributes
are added as well. This fix ensures when an @ModelAttribute is resolved
as a controller method argument it has the highest index in the model.

Issue: SPR-9378

This renaming more intuitively expresses the relationship between
subprojects and the JAR artifacts they produce.

Tracking history across these renames is possible, but it requires
use of the --follow flag to `git log`, for example

    $ git log spring-aop/src/main/java/org/springframework/aop/Advisor.java

will show history up until the renaming event, where

    $ git log --follow spring-aop/src/main/java/org/springframework/aop/Advisor.java

will show history for all changes to the file, before and after the
renaming.

See http://chrisbeams.com/git-diff-across-renamed-directories

 - Eliminate trailing whitespace

 - Update long method signatures to follow framework whitespace
   conventions

   Based on the following search,

       $ git grep -A3 '^.public .* .*([^\{;]*$' */src/main

   the strong convention throughout the framework when dealing with
   methods having long signatures (i.e. many parameters) is to break
   immediately after the opening paren, indent two tabs deeper and break
   lines around 90 characters as necessary. Such signatures should also
   be followed by a newline after the opening curly brace to break
   things up visually.

   The files edited in this commit had a particularly different style of
   intenting arguments to align with each other vertically, but the
   alignment only worked if one's tabstop is set at four spaces.
   When viewed at a different tabstop value, the effect is is jarring,
   both in that it is misaligned and significantly different from most
   of the framework. The convention described above reads well at any
   tabstop value.

overhaul of support package arrangements for handler method processing; added missing package-info files

added MethodValidationInterceptor/PostProcessor for Hibernate Validator 4.2 based method validation; renamed Spring's variant of @Valid to @Validated

added SmartValidator interface with general support for validation hints; added custom @Valid annotation with support for JSR-303 validation groups; JSR-303 SpringValidatorAdapter and MVC data binding provide support for validation groups (SPR-6373)