TypeDescriptor should support arbitrary levels of meta-annotations [SPR-12793]

[spring-projects-issues]

Sam Brannen opened SPR-12793 and commented

Status Quo

The getAnnotation() method in TypeDescriptor currently only supports a single level of meta-annotations.

In other words, meta-annotations on meta-annotations will never be found, and this does not align with Spring's standard support for meta-annotations with arbitrary levels.

For example, @NumberFormat and @DateTimeFormat are supported as meta-annotations but not as meta-meta-annotations.

Deliverables

1. Alter the search algorithm used in TypeDescriptor.getAnnotation() so that arbitrary levels of meta-annotations are supported.

---

Affects: 3.2 GA

Issue Links:

• Support @NumberFormat as a meta-annotation [SPR-12743] #17340 Support @NumberFormat as a meta-annotation ("depends on")
• AnnotationUtils.findAnnotation() should support arbitrary levels of meta-annotations [SPR-11448] #16074 AnnotationUtils.findAnnotation() should support arbitrary levels of meta-annotations
• MetaAnnotationUtils should support arbitrary levels of meta-annotations [SPR-11470] #16095 MetaAnnotationUtils should support arbitrary levels of meta-annotations

Referenced from: commits 04d6afe

[spring-projects-issues]

Sam Brannen commented

Resolved as described in GitHub commit 04d6afe:

Support arbitrary levels of meta-annotations in TypeDescriptor

Prior to this commit, the getAnnotation() method in TypeDescriptor
only supported a single level of meta-annotations. In other words, the
annotation hierarchy would not be exhaustively searched.

This commit provides support for arbitrary levels of meta-annotations
in TypeDescriptor by delegating to AnnotationUtils.findAnnotation()
within TypeDescriptor.getAnnotation().