How to generate "SampleServlet.java" from swagger spec json/yaml ?

[alumuko]

I think "swagger-codegen-cli.jar" (3.0.27) is unsupported to generate java-servlet.

How I generate SampleServlet.java (that is a pure java http.HttpServlet) from swagger spec?

And I can't find how to generate swagger spec json/yaml from "SampleServlet.java".

Can I get a swagger spec from pure Java http.HttpServlet?