Request - Response API for Android Wear 2.0?

Question

How do I implement a request-response protocol for an Android Wear 2.0 app?

Scenario:

When I tap on a button on the watch, I want it to fetch some data from the phone and display it on the watch's screen.

What I tried:

I implemented a working example using the MessageApi, but I don't like it. I send a dummy "request" in one place using one method, I disregard the PendingResult and then hope that eventually I will receive a message that will be a corresponding response.

Ideally, what I'd like to have is:

byte[] responseBytes = sendRequest(someRequestBytes);

Your "ideal" solution is a synchronous function call, which isn't how inter-device communication works. Wireless data transmission takes time, which is why the Wear data and message APIs are structured asynchronously. — Sterling, Aug 15 '17 at 04:17
@String I'm totally happy with an asynchronous request-response API - Futures, Promises, all that. That's what the title and body of the question is about. — DogeLion, Aug 18 '17 at 10:07
Hmm. In your question you say you've **already** implemented this asynchronously, but you're not happy with it - that you'd prefer a synchronous solution. I didn't see any acknowledgement that synchronous wasn't supported by the architecture. — Sterling, Aug 18 '17 at 14:15
@String I'm not happy because it's not a request-response API. I send a request in one place using one method and then *hope* to receive a message with a response. And I want something like in my snippet above (+- a `Future` wrapper) — DogeLion, Aug 18 '17 at 14:32
And to further clarify: I have something like Vyacheslav wrote below. I just don't like it and I'll probably wrap the API.. unless Android provides a request-response API. — DogeLion, Aug 18 '17 at 14:38
Then there's your answer. You want a different API than what Google has provided for Wear. Unless someone else has built a "wrapper" for the Wear APIs in the form that you want (I'm not aware of one, but it's possible that one exists), you'll need to build such a wrapper yourself from the APIs that **are** provided. — Sterling, Aug 18 '17 at 15:55

score 0 · Answer 1 · edited Aug 14 '17 at 16:48

0

I'm not sure what you have tried.

But this code should work to send a byte array.

Wearable.MessageApi.sendMessage(googleApiClient, transcriptionNodeId,
            VOICE_TRANSCRIPTION_MESSAGE_PATH, voiceData).setResultCallback(
                  new ResultCallback() {
                      @Override
                      public void onResult(SendMessageResult sendMessageResult) {
                          if (!sendMessageResult.getStatus().isSuccess()) {
                              // Failed to send message
                          }
                      }
                  }
            );

voiceData is a simple byte array. This array will be received by both wearable and handheld device.

https://developer.android.com/training/wearables/data-layer/messages.html

To retrieve the data use this:

@Override
public void onMessageReceived(MessageEvent messageEvent) {
    if (messageEvent.getPath().equals(YOUR_TEXT)) {
        messageEvent.getData();//this is your byte array
    }
}

edited Aug 14 '17 at 16:48

TofferJ

4,678
1
37
49

answered Aug 14 '17 at 16:10

Vyacheslav

26,359
19
112
194

Umm, but where's the response ? – DogeLion Aug 14 '17 at 16:20
Your code is exactly what I described in my question - I did this, it works, I don't like it and am looking for a more request-response oriented API :) But thanks anyway! – DogeLion Aug 14 '17 at 16:31
this is the fastest solution. – Vyacheslav Aug 14 '17 at 16:31
Fastest in terms of? – DogeLion Aug 14 '17 at 16:32
1

There are two methods which help to transfer the data. The other method is to use Wearable.DataApi. But has got some disadvantages : huge transfer time for bulky objects – Vyacheslav Aug 14 '17 at 17:20

Request - Response API for Android Wear 2.0?

1 Answers1