[REQ] [java-undertow-server] Provide HttpHandler that checks input JSON and params

Is your feature request related to a problem? Please describe.

When writing the API spec, the schemas for the endpoints define required fields, possibly regexes for path params, input format, etc. At the moment the template forces the user to implement all of those checks on their own while referencing the spec - a tedious task that could be done "once and for all".

Describe the solution you'd like

A HttpHandler that uses the generated openapi.json to check the input and paramaters. It would hand off control to the user's handler once all checks are passed.

Describe alternatives you've considered

An abstract base class that all user handlers have to subclass in order to use the generated code.

Additional context

I am about to implement this and #4257 myself, but I was hoping to get some feedback before tackling the tasks. Maybe there's already a lib that does something similar from an openAPI spec?

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After looking through the packages used in the generated code, it seems like it uses light-4j which seems to have a validator somewhere, but the docs aren't clear on how to use it, whether it's used, how to configure it, etc.

[20Aditya]

Hi, did you find how to use it. I am facing exactly the same issue as I have to implement the checks myself.

I didn't look further into is as I don't need it anymore