thirePartyProxy.java

@Get("/test")
public HttpResponse getTest(RequestContext ctx) {
    CompletableFuture<HttpResponse> future = new CompletableFuture<>();
    WebClient client = WebClient.of("https://icanhazdadjoke.com");
    HttpResponse response = client.execute(RequestHeaders.of(HttpMethod.GET, "/", HttpHeaderNames.ACCEPT, HttpHeaderValues.APPLICATION_JSON));
    ContextAwareEventLoop eventLoop = ctx.eventLoop();
    response.aggregate().thenAcceptAsync(aggregatedRes -> {
        AggregatedHttpResponse res = ...  // do something with `aggregatedRes`
        future.complete(res.toHttpResponse());
    }, eventLoop);
    return HttpResponse.from(future);
}