title: Generating Swagger documentation from existing REST api
body: <p>Given an existing JAX-RS-annotated API that accepts &amp; returns json, with jackson-annotated types, is there a way that I can generate some YAML Swagger documentation?  My plan B is to write some code that uses reflection to find REST-annotated types, make a hashmap of their arguments &amp; returns, and then crawl those classes for Jackson annotations, and generate the documentation that way.</p>
  
  <p>I would prefer to use a solution that already exists to writing a one-off thing.  I found this Swagger module that claims it can parse Jackson configurations (<a href="https://github.com/FasterXML/jackson-module-swagger" rel="nofollow noreferrer">https://github.com/FasterXML/jackson-module-swagger</a>) but I don't know enough about Swagger to understand what modules are and whether I can use it to generate Swagger from existing code.</p>