Right, do you mean that both of these providers are custom as far
as the JAX-RS implementation is concerned ?
Yes, exactly. In this case JAX-RS currently doesn't specify which one should be used.
Sure, I see what you mean now.
I guess my only doubt at this stage is, should the providers
offered by MVC implementation (or some other *spec-implementaion*
API) have a special treatment status, as far as JAX-RS is
concerned ? Example, be annotated with some @DefaultProvider
annotation (to be introduced in JAX-RS) ? In this case JAX-RS,
seeing two MyObject exception mappers, will select the one which
has no @DefaultProvider.
Not sure if something like @DefaultProvider is flexible enough. Maybe this "default provider" vs "custom provider" use case is just one special case? I mean, it is always possible to have multiple exception mappers on the classpath if they are provided by different libraries. And in this case it would be nice to have some clear rules on how to handle this situation.
May be using @Priority is simpler, but it would require
application mappers to know how to set their own @Priority to
ensure it is high or low enough.
For filters and interceptors there is already javax.ws.rs.Priorities which contains constants which can be used for ordering. So this could also be used for exception mappers and param providers.
The problem with @DefaultProvider
is that it is probably too late as ex MVC API would need updated
after 2.1 is out.
That wouldn't be a problem, because MVC will go final after JAX-RS and therefore could depend on JAX-RS 2.1.
