Since the introduction of synthesized annotation support in Spring
Framework 4.2 (a.k.a., merged annotations), the toString()
implementation attempted to align with the formatting used by the JDK
itself. However, Class annotation attributes were formatted using
Class#getName in Spring; whereas, the JDK used Class#toString up until
JDK 9.
In addition, JDK 9 introduced new formatting for toString() for
annotations, apparently intended to align with the syntax used in the
source code declaration of the annotation. However, JDK 9+ formats enum
annotation attributes using Enum#toString instead of Enum#name, which
can lead to issues if toString() is overridden in an enum.
This commit updates the formatting used for synthesized annotations by
ensuring that toString() generates a string that is compatible with the
syntax of the originating source code, going beyond the changes made in
JDK 9 by using Enum#name instead of Enum#toString.
Closes gh-28015
7139a877f4