Empty Maps are preferably initialized without capacity (not initializing them at all or lazily initializing with default capacity when needed).
Issue: SPR-17105
Introduces getBeanProvider(Class) and getBeanProvider(ResolvableType), also narrowing getBean(String, Class) and isTypeMatch(String, Class) to a non-null Class argument and enriching NoUniqueBeanDefinitionException with a full ResolvableType. In addition, ObjectProvider supports iterable/stream access for collection-style resolution of multiple matching beans now, and collection injection falls back to an empty collection in a single-constructor case with non-null arguments.
Issue: SPR-17075
Issue: SPR-11419
Issue: SPR-15338
Provides a non-null guarantee for MethodMatcher's targetClass argument and strict separation between IntroductionAwareMethodMatcher and regular MethodMatcher, enabling DefaultAdvisorChainFactory to defer its IntroductionAdvisor determination until encountering an actual IntroductionAwareMethodMatcher (even behind union/intersection).
Issue: SPR-17068
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
Introduces a configure method pattern for Supplier-style configuration and a common SingletonSupplier decorator for method reference suppliers. Also declares jcache.config and jcache.interceptor for non-null conventions.
Issue: SPR-17021
Includes a clarification of ThreadPoolExecutor configuration options and a note on early AsyncConfigurer initialization.
Issue: SPR-16944
Issue: SPR-16945
Allows for skipping the now-deprecated postProcessPropertyValues callback with its expensive PropertyDescriptor retrieval requirement. RequiredAnnotationBeanPostProcessor (which is dependent on postProcessPropertyValues) and the @Required annotation itself are also deprecated now: in favor of constructor injection (or afterPropertiesSet).
Issue: SPR-16918
Polish a few issue identified when adding checkstyle to the
build. Although checkstyle is not enforcing rules on tests,
these are a few minor changes that are still worth making.
Issue: SPR-16968
Juergen Hoeller
Sam Brannen
Kazuhiro Sera
Сергей Цыпанов
Bhavani Shekhawat
Rossen Stoyanchev
Sebastien Deleuze
Phillip Webb