The first question I get from most of the developers I get is, Is there any way to auto generate your groovy file by by using swagger or may be plain json file?
Is there any way to do it?
I don't understand the question. What do you want to achieve? Do you NOT want to use Groovy file to define a contract? If that's the case then the answer is - you can use the Pact file (a json) to define the contract or you can plugin whatever you want. It's all written in the documentation - http://cloud.spring.io/spring-cloud-static/Dalston.SR4/multi/multi__pluggable_architecture.html.
As for Swagger we don't support it mainly because it's a schema. The reasons behind this decision are in this issue - https://github.com/spring-cloud/spring-cloud-contract/issues/136