How to use

discarding

method

in

java.net.http.HttpResponse$BodyHandlers

  private void upgradeToH2c(Target target){
    try {
      httpClient.send(HttpRequest.newBuilder()
          .method("options", HttpRequest.BodyPublishers.noBody())
          .uri(URI.create(target.url()))
          .build(),
          HttpResponse.BodyHandlers.discarding());
    } catch (IOException | InterruptedException e) {
      throw new RuntimeException(e);
    }
  }
}