Cache the annotation-driven converters created from a AnnotationFormatterFactory to improve performance [SPR-7104]

[spring-projects-issues]

Keith Donald opened SPR-7104 and commented

Currently FormattingConversionService delegates to an AnnotationFormatterFactory on every conversion attempt to obtain the Printer or Parser to print/parse an annotated-field value, respectively. This is a bit inefficient, especially since each invocation also results in generic type introspection against the Printer/Parser instance.

We can improve performance by caching by Annotation + field type. So when the same annotation with the same attributes is found for the same field type across different fields, we'd still resolve the same (cached) Printer/Parser instance.

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Affects: 3.0.2