chain_http.java

public void testFoo() {
        Vertx vertx = Vertx.vertx();

        HttpClient client = vertx.createHttpClient();
        
        getWithFuture(client, "url1")
        .thenCompose(resp1 -> getWithFuture(client, "url2/" + resp1.statusMessage()))
        .thenCompose(resp2 -> getWithFuture(client, "url3/" + resp2.statusMessage()))
        .whenComplete(((resp3, t) -> {
            if (t != null) {
                t.printStackTrace();
            } else {
                System.out.println("All done");
            }
        }));
    }
    
    private CompletableFuture<HttpClientResponse> getWithFuture(HttpClient client, String url) {
        CompletableFuture<HttpClientResponse> cf = new CompletableFuture<>();
        HttpClientRequest req = client.get(url);
        req.exceptionHandler(cf::completeExceptionally);
        req.handler(cf::complete);
        return cf;
    }