Hakan Altindag takes us through compression options when working with Elasticsearch:
18th of June 2020 Elastic has released Elasticsearch 7.8 with their java library which makes handling compressed data easier, see here the release notes: Elasticsearch 7.8 release notes
Even though you enabled Elasticsearch to send you compressed data, Elasticsearch will only compress it when the client is requesting for it. The java client can request for it by sending additional request options within the http request, see below for an example:
Read on to see how to enable this, as well as how clients can use it.