Wrong content negotiation when Swagge4J fetches swagger descriptions

[izzyblues]

Hello,
I am using Swagger4J to parse Swagger descriptions available on the iServe website (e.g., http://iserve.kmi.open.ac.uk/iserve/id/documents/18ee0842-f492-4f43-9073-ade556155526).
The website returns the swagger UI when "Accept: text/html" appears in the HTTP request header. Otherwise, it will return the JSON-based Swagger document when the header contains "Accept: application/json".
It looks like that Swagger4J is not able to fetch such JSON documents because in the HTTP request header contains "Accept: text/html, image/gif, image/jpeg, *; q=.2, /; q=.2".

I suppose that the header should contain "application/json" instead of "text/html". Isn't it?

Thank you very much for your help.
Cheers,

Luca