JAX-RS: migrate DefaultValue annotation on request parameters

[bottemav]

What needs to be done

Migrate javax.ws.rs.DefaultValue annotation on request parameters to the defaultValue attribute of org.springframework.web.bind.annotation.RequestParam

Why it needs to be done

javax.ws.rs.DefaultValue is one of the JAX-RS annotations that needs to be migrated to Spring Web. The annotation can be applied to a couple of request annotations like QueryParam, FormParam, PathParam, ... but let's start with QueryParam.

Acceptance Criteria

After applying the recipe, the RequestParam annotation has a defaultValue attribute with the same value as the javax.ws.rs.DefaultValue annotation and the javax.ws.rs.DefaultValue annotation is removed.

Given a method parameter annotated with both javax.ws.rs.DefaultValue and javax.ws.rs.QueryParam annotations
When the recipe MigrateJaxRsRecipe is applied
Then the method parameter is annotated with a org.springframework.web.bind.annotation.RequestParam having an defaultValue attribute with the same value as the javax.ws.rs.DefaultValue annotation

Additional Information

An example:
public String getAllPersons(@DefaultValue("0") @QueryParam("page") int page)
should be migrated to
public String getAllPersons(@RequestParam(required = false, value = "page", defaultValue="0") int page)

[fabapp2]

Thanks for adding this @bottemav
It's a long way to fully migrate JAX-RS to Boot...
would you like to look into it and contribute something as another step in this direction?

[bottemav]

@fabapp2 Sure, I'd love to.

I think I will create a new Recipe for this

CopyAnnotationAttribute (
   String sourceAnnotation,
   String sourceAnnotationAttribute,
   String targetAnnotation,
   String targetAnnotationAttribute,
   boolean removeSourceAnnotation
)

For this ticket it will be used this way:

CopyAnnotationAttribute (
   "javax.ws.rs.DefaultValue", "value", "org.springframework.web.bind.annotation.RequestParam", "defaultValue", true
);

I'm still in doubt whether removing the source annotation is part of the recipe or not.

[fabapp2]

HI @bottemav

I like the idea of implementing a generic recipe.
IMHO it should be an isolated step and not combined with deleting the recipe.
Mainly because I could imagine a composition of these recipes where multiple annotation attributes need to be moved and then you wouldn't want to delete the annotation straight away but do it in a separate step.
A quick check made me realize a DeleteAnnotaion does not exist.
I am more than open to discussing in case you have a different opinion.
I will assign this issue to you. Thanks for contributing 🚀

[fabapp2]

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