Investigate in providing a JAX-RS based endpoint

[poikilotherm]

Currently, Dataverse uses a very classic Servlet although it's a Jakarta EE application.

Maybe it would be a good thing to provide a sane but extensible JAX-RS based endpoint implementation as a separate module?

[poikilotherm]

Looked at this again briefly.

When using a JAX-RS endpoint instead of a servlet, the main entry point is DataProvider.handle(), receiving an OAIRequest or a Builder<OAIRequest>.

This is handed down in a few different ways as a Request object (which is the model for the OAI-PMH <request> response part) and as a OAICompiledRequest. The compilation of this request object does validation on creation etc.

A JAX-RS endpoint might make use of an @BeanParameter, injecting the POJO directly. The OAICompiledRequest could be declared an interface with a reasonable default implementation.

A distinct JAX-RS module (or within same module but with JAX-RS made an optional dependency) might provide another implementation using @QueryParam data binding and JAX-RS based validation.

(The validation would be moved outside of OAIRequest, so it can be reused.)