如何通过okHttp实现异步数据的读取

Question

我希望结合Java 8的CompleteFuture特性，编写一个okHttp异步抓取网络数据，并输出到服务端。

 @Override
    public void run(OpcUaClient client, CompletableFuture<OpcUaClient> future) throws Exception {
        // synchronous connect
        client.connect().get();

        List<NodeId> nodeIds = ImmutableList.of(new NodeId(2, "HelloWorld/ScalarTypes/Int32"));

        //建立HTTP请求
        OkHttpClient okHttpClient = new OkHttpClient();
        Request.Builder requestBuilder = new Request.Builder().url("http://localhost:8080/greeting");


        for (int i = 0; i < 10; i++) {

            Request request = requestBuilder.build();
            Call call= okHttpClient.newCall(request);

            final GreetingModel[] greetingModel = {new GreetingModel()};


            call.enqueue(new Callback() {
                @Override
                public void onFailure(@NotNull Call call, @NotNull IOException e) {
                    logger.error("Writing is wrong");
                }

                @Override
                public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                    String json = response.body().string();
                    logger.info("Connecting is good");
                    greetingModel[0] = JSON.parseObject(json, GreetingModel.class);
                }
            });

            Variant v = new Variant(greetingModel[0].getId());

            // don't write status or timestamps
            DataValue dv = new DataValue(v, null, null);

            // write asynchronously....
            CompletableFuture<List<StatusCode>> f =
                client.writeValues(nodeIds, ImmutableList.of(dv));

            // ...but block for the results so we write in order
            List<StatusCode> statusCodes = f.get();
            StatusCode status = statusCodes.get(0);

            if (status.isGood()) {
                logger.info("Wrote '{}' to nodeId={}", v, nodeIds.get(0));
            }
        }

        future.complete(client);
    }

}
 

这个是源代码，我希望greeting里面提取到的数据可以与最后

CompletableFuture<List<StatusCode>> f =
                client.writeValues(nodeIds, ImmutableList.of(dv));  

实现数据同步，但是实际执行起来是先并行写入，然后再是从http获取请求。如图

主要是不知道okhttp和Java 8 的CompleteFuture异步方式怎么结合，麻烦各位解惑，感恩~