Improve method naming in MethodParameter class [SPR-6055]

[spring-projects-issues]

Oliver Drotbohm opened SPR-6055 and commented

Implementing custom WebArgumentResolver s you intensively deal with the @MethodParameter@ parameter you get handed in resolveArgument(..). It's API could need some minor improvements to reduce surprises:

1. getAnnotations() does not return the annotations of the parameter but the annotations of the method. To access the actual parameter annotations you have to call getParameterAnnotations(). So I'd suggest to let getAnnotations() return the parameter annotations instead, drop getParameterAnnotations() and introduce a getMethodAnnotations() to return the method's annotations.
2. As in most cases in inspecting parameter annotations you look for a particular type of annotation, it would be cool to be able to simply call some kind of hasAnnotation(Class<? extends Annotation> annotation) or maybe <T extends Annotation> T getAnnotation(Class<T> annotation) to access the annotation directly or get null if the parameter does not contain the an annotation of the given type. This would save the client from extracting all annotations and teadiously iterating over all of them.

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Affects: 3.0 M3

[spring-projects-issues]

Juergen Hoeller commented

Good point - getAnnotations isn't very specific there. It's new in 3.0, with getParameterAnnotations being the older one. Consequently, I've renamed getAnnotations to getMethodAnnotations and kept getParameterAnnotations as-is for compatibility purposes (and to clearly indicate the source of the annotations). I've also added getMethodAnnotation(T) and getParameterAnnotation(T) convenience methods.

Juergen