Spring Cloud Openfeign Change default CollectionFormat

Is your feature request related to a problem? Please describe. If I want to change collection format to CSV for the all methods, I have to add @CollectionFormat annotation on each method.

Describe the solution you'd like @CollectionFormat could be a class level annotation, or I could provide a property. Manual feign client creation should have this option.

Describe alternatives you've considered Here's my workaround on how to change the default format from EXPLODED to CSV:

feignClientBuilder.forType(MyClient.class, "my-" + id)
                .url(settings.getUrl())
                .customize(builder -> builder
                        .requestInterceptor(
                                new BasicAuthRequestInterceptor(settings.getUsername(), settings.getPassword())
                        )
                        .contract(new SpringMvcContract() {
                            @Override
                            protected boolean processAnnotationsOnParameter(MethodMetadata data, Annotation[] annotations, int paramIndex) {
                                data.template().collectionFormat(CollectionFormat.CSV);
                                return super.processAnnotationsOnParameter(data, annotations, paramIndex);
                            }
                        })
                )
                .build();

I can change it in the interceptor also but it's too late to take effect, QueryTemplates are already build with EXPLODED by that point.

Comment From: OlgaMaciaszek

@Sam-Kruglov It makes sense. Would you like to submit a PR?

Comment From: OlgaMaciaszek

Fixes gh-596.