Differentiate between TypeDescriptors with same annotations but different attributes [SPR-13714]

[spring-projects-issues]

Nathan Piper opened SPR-13714 and commented

The current implementation of TypeDescriptor.equals only checks for the presence of matching annotations when comparing two type descriptors (as apposed to testing property values for the same annotation on both type descriptors). This ultimately leads to problems when used with the GenericConversionService cache as the service can return the wrong converter when multiple converters are being used that rely on annotations with distinct property values.

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Affects: 4.2.3

Reference URL: #924

Issue Links:

• ConversionService performance regression [SPR-14929] #19496 ConversionService performance regression
• AnnotationFormatterFactory should support @AliasFor [SPR-14844] #19410 AnnotationFormatterFactory should support @AliasFor
• Improve performance for conversions using a method parameter based type descriptor with annotations [SPR-14926] #19493 Improve performance for conversions using a method parameter based type descriptor with annotations

[spring-projects-issues]

Nathan Piper commented

I have submitted a fix in this pull request:

#924

[spring-projects-issues]

Juergen Hoeller commented

As far as I can see, this is actually intentional: Converters are usually triggered by a specific annotation type and then process the specific annotation attributes for each invocation; see e.g. AnnotationFormatterFactory. For that purpose, caching converters per annotation type is optimal.

That said, I do see the point that registering converters for specific annotation attribute values would be nice to have. I'll turn this into an improvement ticket for the 4.3 timeframe, assuming that we're able to accept the cache overhead of one entry per attribute combination then.

Juergen

[spring-projects-issues]

Juergen Hoeller commented

Rolled in a slightly revised form, including the suggested TypeDescriptorTests unit test as well as an actual test for converter matching in GenericConversionServiceTests.

Juergen