API Documentation

Swagger is the most popular tool for designing, building, and documenting RESTful APIs. It has been created by SmartBear, the designers of a very popular tool for SOAP Web Services, SoapUI. I think that might be sufficient recommendation for those who have long experience with SOAP. Anyway, with Swagger, we can design APIs using notation and then generate source code from it, or the other way around, where we start with the source code and then generate a Swagger file. With Spring Boot, we use the second option. 

Using Swagger 2 together with Spring Boot

The integration between Spring Boot and Swagger 2 is realized by the Springfox project. It examines application at runtime to infer API semantics...