Issue reported above is get comma separated values as List on Server side (for Query Param).
But for Jaxrs- CXF client, when we are trying to build URL from a List or Array, I don't see a way to build URL as comma separated values
The solution provided to use "parse.query.value.as.collection" contextual property is not used in org.apache.cxf.jaxrs.client.AbstractClient and org.apache.cxf.jaxrs.impl.UriBuilderImpl
And works only on server side while receiving request, not on client side (i.e while building URL from List).
Switching to "multi" option for query param means, I need to ask all existing clients to update the way they build URL, which is not feasible.