According to the documentation it is possible to use the Spring Reactive WebClient with a different server as Netty:
WebClient provides a higher level
Add dependency:
org.eclipse.jetty:jetty-reactive-httpclient:1.0.3
And then:
HttpClient httpClient = new HttpClient();
ClientHttpConnector connector = new JettyClientHttpConnector(httpClient);
WebClient webClient = WebClient.builder().clientConnector(connector).build();
Source: https://docs.spring.io/spring/docs/current/spring-framework-reference/web-reactive.html#webflux-client-builder-jetty