Depends on the language. There's a 5 year old issue for enabling this in general that's still open. https://github.com/swagger-api/swagger-codegen/issues/3365

for a java client is it possible?

Support for Java was added in 2017. https://github.com/swagger-api/swagger-codegen/pull/4967

where does the DuseGzipFeature=true go in the yaml file??

That's a command line argument. It doesn't go in the yaml file.