See gh-2060

See gh-2060

* Make AutowireUtils public and protect its current API
* Move ParameterAutowireUtils features to AutowireUtils

Closes gh-2060

Closes gh-22283

Closes gh-1452

See gh-1452

See gh-2019

Update code that has accidentally used spaces instead of tabs.
Also remove all trailing whitespace.

Issue: SPR-16968

use getOrDefault instead of ternary operator

Based on IntelliJ IDEA 2017.3 introspection results.

Issue: SPR-15756

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 consistent use of ResolvableType.resolve() wherever applicable.

Issue: SPR-15011

Issue: SPR-13188

Issue: SPR-12385

Fix remaining Java compiler warnings, mainly around missing
generics or deprecated code.

Also add the `-Werror` compiler option to ensure that any future
warnings will fail the build.

Issue: SPR-11064

Also using ClassUtils.forName in AutowireUtils now in order to accept all common class name formats.

Issue: SPR-11034

Issue: SPR-11034

XML-defined arguments values are initially turned into TypedStringValue wrappers. If we encounter an unresolved argument, we need to unwrap such a TypedStringValue and then try to treat its content as a class name.

Issue: SPR-11034

Also optimized getTypeForFactoryMethod's implementation for non-generic factory methods, and reduced calls to getResolvedFactoryMethod in order to avoid repeated synchronization.

Issue: SPR-11034

 - Now avoiding NullPointerExceptions in GenericTypeResolver's
   resolveReturnTypeForGenericMethod() in case the supplied ClassLoader
   is null.
 - AutowireUtils.resolveReturnTypeForFactoryMethod() now properly
   asserts that the supplied ClassLoader is not null.
 - Fixed copy-n-paste errors in Javadoc for
   AutowireUtils.resolveReturnTypeForFactoryMethod().

Issue: SPR-10411

We're consistently resolving class names now, and the entire algorithm moved from GenericTypeResolver to the internal AutowireUtils helper in the bean factory package.

Issue: SPR-10411

Issue: SPR-10130

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

Issue: SPR-10130

Fix serialization warnings by applying @SuppressWarnings("serial")
when appropriate.

In certain cases and for unknown reasons, a correctly-placed
@SuppressWarnings("serial") annotation will fix the warning at the
javac level (i.e. the Gradle command-line), but will produce an
"unnecessary @SuppressWarnings" warning within Eclipse. In these
cases, a private static final serialVersionUID field has been added
with the default value of 1L.

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

fixed registerResolvableDependency mechanism to correctly handle non-serializable factory objects (SPR-7264)

Servlet/Portlet ApplicationContexts use a specific id based on servlet/portlet name; DefaultListableBeanFactory references are serializable now when initialized with an id; scoped proxies are serializable now, for web scopes as well as for singleton beans; injected request/session references are serializable proxies for the current request now

revised support for annotated factory methods (merged @FactoryMethod functionality into JavaConfig facility)

EL container integration; support for contextual objects; removal of deprecated Spring 2.0 functionality; Java 5 code style