Prior to this commit, Spring offered two top-level implementations of
the BeanNameGenerator strategy: DefaultBeanNameGenerator and
AnnotationBeanNameGenerator. The latter is used as the default bean
name generator for beans picked up via component scanning. In a typical
application, this strategy works well; however, if multiple component
scanned beans have the same simple class name (i.e., identical names
ignoring the package), a BeanDefinitionStoreException is thrown.
To address such naming conflicts, users of Spring have had to implement
a custom BeanNameGenerator based on the fully qualified class name of
such components.
Similar conflicts can arise with components registered via
configuration class imports (i.e., via @Import), and
ConfigurationClassPostProcessor addresses this via an anonymous inner
class that extends AnnotationBeanNameGenerator but falls back to using
the fully qualified class name if an explicit bean name is not provided
via an annotation.
This commit extracts the implementation of
ConfigurationClassPostProcessor's internal BeanNameGenerator into a new
top-level FullyQualifiedAnnotationBeanNameGenerator class that can be
used to disambiguate between same-named components residing in
different packages that are picked up via component scanning. This bean
name generator can be configured via @ComponentScan's nameGenerator
attribute.
Closes gh-24114
b4c91e7dac