Develop Reference

How do I send data from an android wearable device to a phone in the form of a a simple text file containing data?

I have a wearable app. The app after it finishes has data like time/date, UUID, Geo location, parameters selected displayed in front of me like a Data Report or Log in several TextViews underneath each other. Like a list. I want this data to be transferred from my wearable device to my android phone.
Now I have to ask does the WearOS app the pairs the phone with the watch enables such a thing? Like can the data be sent through it? OR what exactly can I do? I read about Sync data items with the Data Layer API in the documentation, but I'm not sure if the code snippets provided would help achieve what I want.
public class MainActivity extends Activity {
private static final String COUNT_KEY = "com.example.key.count";
private DataClient dataClient;
private int count = 0;
...
// Create a data map and put data in it
private void increaseCounter() {
PutDataMapRequest putDataMapReq = PutDataMapRequest.create("/count");
putDataMapReq.getDataMap().putInt(COUNT_KEY, count++);
PutDataRequest putDataReq = putDataMapReq.asPutDataRequest();
Task<DataItem> putDataTask = dataClient.putDataItem(putDataReq);
}
...
}
The data I display in the textviews are called through methods that I call things like: getLocation, getUUID, getDateTime, getSelections, etc... when I click a button I call them in the setOnClickListener. I want this data in the TextViews to be placed in a file or something like that and send them over to the mobile phone from the watch when they're generated.
private void getDateTime()
{
SimpleDateFormat sdf_date = new SimpleDateFormat("dd/MM/yyyy");
SimpleDateFormat sdf_time = new SimpleDateFormat("HH:mm:ss z");
String currentDate= sdf_date.format(new Date());
String currentTime= sdf_time.format(new Date());
textView_date_time.setText("Date: "+currentDate+"\n"+"Time: "+currentTime);
}
#SuppressLint("SetTextI18n")
private void getUUID()
{
// Retrieving the value using its keys the file name
// must be same in both saving and retrieving the data
#SuppressLint("WrongConstant") SharedPreferences sh = getSharedPreferences("UUID_File", MODE_APPEND);
// The value will be default as empty string because for
// the very first time when the app is opened, there is nothing to show
String theUUID = sh.getString(PREF_UNIQUE_ID, uniqueID);
// We can then use the data
textView_UUID.setText("UUID: "+theUUID);
}
#SuppressLint("SetTextI18n")
private void getSelections()
{
textView_data_selected.setText("Tool No.: "+c.getToolNo()+
"\nTool Size: " +c.getToolSizeStr()+
"\nFrom Mode: " +c.getCurrentModeStr()+
"\nGoto Mode: " +c.getModeStr()+
"\nMethod: " +c.getMethodStr()+
"\nBit Duration: " +c.getBitDuration()+
"\nUpper bound" +c.getUpStageValue()+
"\nLower bound: "+c.getDownStageValue());
}
The above are examples of the methods I use to get the data. then I call them here:
gps_btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (Build.VERSION.SDK_INT >= 26) {
getLocation();
getDateTime();
getUUID();
getSelections();
}
else
{
//ActivityCompat.requestPermissions(get_location.this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
Toast.makeText(get_location.this,"Build SDK too low",Toast.LENGTH_SHORT);
}
}
});
Now how do I take all this and send it over from my device to the the phone?
Note: The data report I want to send as a file, I want it done subtly like something done in the background. I don't know what else to do or where to look.

You have two options if you want to use the Data Layer, one is to use the MessageClient API to bundle your data up in a message and send it directly to the handheld. The easiest here would be to create an arbitrary JSONObject and serialize your data as a JSON string you can stuff into a message. For example:
try {
final JSONObject object = new JSONObject();
object.put("heart_rate", (int) event.values[0]);
object.put("timestamp", Instant.now().toString());
new MessageSender("/MessageChannel", object.toString(), getApplicationContext()).start();
} catch (JSONException e) {
Log.e(TAG, "Failed to create JSON object");
}
In my case, I do this in my onSensorChanged implementation, but you can insert this wherever you are updating your text.
MessageSender is just a threaded wrapper around the MessageClient:
import java.util.List;
class MessageSender extends Thread {
private static final String TAG = "MessageSender";
String path;
String message;
Context context;
MessageSender(String path, String message, Context context) {
this.path = path;
this.message = message;
this.context = context;
}
public void run() {
try {
Task<List<Node>> nodeListTask = Wearable.getNodeClient(context.getApplicationContext()).getConnectedNodes();
List<Node> nodes = Tasks.await(nodeListTask);
byte[] payload = message.getBytes();
for (Node node : nodes) {
String nodeId = node.getId();
Task<Integer> sendMessageTask = Wearable.getMessageClient(context).sendMessage(nodeId, this.path, payload);
try {
Tasks.await(sendMessageTask);
} catch (Exception exception) {
// TODO: Implement exception handling
Log.e(TAG, "Exception thrown");
}
}
} catch (Exception exception) {
Log.e(TAG, exception.getMessage());
}
}
}
The other option is to create a nested hierarchy of data items in the Data Layer and implement DataClient.OnDataChangedListener on both sides, such that changes that are written in on one side are automatically synchronized with the other. You can find a good walkthrough on how to do that here.
For your specific case, just packing it in a JSON object would probably be the simplest. The writing out to your preferred file format you can then implement on the handheld side without needing to involve the wear side.

Getting the calling fragment within an asynchronous task

Aim
In a fragment, I have a search bar which looks for online news about what the user typed. I would want to display these news (title + description + date of publication + ... etc.) in the GUI, as vertical blocks.
Implementation
Explanations
In the fragment, within the search event handling, I instanciated an asynchronous task and execute it with the good URL REST API I use to do the search.
In the asynchronous task, I make use of this REST API (thanks to the URL and some required parameters as an authorization key, etc.). When my asynchronous task gets answered, it must update the fragment's GUI (i.e.: it must vertically stack GUI blocks containing the titles, descriptions, etc. of the got news).
Sources
You will find sources in the last part of this question.
My question
In the asynchronous task (more precisely: in its function that is executed after having got the answer), I don't know how to get the calling fragment. How to do this?
Sources
Fragment part
private void getAndDisplayNewsForThisKeywords(CharSequence keywords) {
keywords = Normalizer.normalize(keywords, Normalizer.Form.NFD).replaceAll("[^\\p{ASCII}]", "");
new NetworkUseWorldNews().execute("https://api.currentsapi.services/v1/search?keyword=" + keywords + "&language=en&country=US");
}
Asynchronous task part
public class NetworkUseWorldNews extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String[] urls) {
StringBuilder string_builder = new StringBuilder();
try {
URL url = new URL(urls[0]);
HttpsURLConnection https_url_connection = (HttpsURLConnection) url.openConnection();
https_url
_connection.setRequestMethod("GET");
https_url_connection.setDoOutput(false);
https_url_connection.setUseCaches(false);
https_url_connection.addRequestProperty("Authorization", "XXX");
InputStream input_stream = https_url_connection.getInputStream();
BufferedReader buffered_reader = new BufferedReader(new InputStreamReader(input_stream));
String line;
while((line = buffered_reader.readLine()) != null) {
string_builder.append(line);
}
buffered_reader.close();
} catch (IOException e) {
e.printStackTrace();
}
return string_builder.toString();
}
#Override
protected void onPostExecute(String result) {
try {
JSONObject news_response_http_call = new JSONObject(result);
switch(news_response_http_call.getString("status")) {
case "ok":
JSONArray news = news_response_http_call.getJSONArray("news");
for(int i = 0; i < news.length(); i++) {
JSONObject a_news = news.getJSONObject(i);
String title = a_news.getString("title");
String description = a_news.getString("description");
String date_of_publication = a_news.getString("published");
String url = a_news.getString("url");
String image = a_news.getString("image");
System.out.println(title + ": " + date_of_publication + "\n" + image + "\n" + url + "\n" + description);
WorldNewsFragment world_news_fragment = ...;
}
break;
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}

If I am right, you want to update View of your caller Fragment. if FragmentA called service then FragmentA should be update.
However the approach you are asking is wrong. Instead of getting caller Fragment in your AsyncTask response. You should do it with Callback.
So now you will need to pass callback in AsyncTask. So instead of posting full code, here are already answers with this problem.
Finally your calling syntax will look like.
NetworkUseWorldNews task = new NetworkUseWorldNews(new OnResponseListener() {
#Override
public void onResponse(String result) {
// Either get raw response, or get response model
}
});
task.execute();
Actually I am still very unclear about your question. Let me know in comments if you have more queries.
Must checkout
Retrofit or Volley for calling Rest APIs
Gson for parsing JSON response automatically to models

Calling Async class from Async class in Android not working?

So my goal is to load a random wikipedia page, get the title from it, and then use the wikipedia api to get the correct title to return for display (titles with special characters need "translated" to be able to display them correctly.) My problem comes when I use my JSONRequest class (Async) to try to execute the api url and create a JSON object. When it tries to execute, it freezes and doesn't go any further (but does not crash.) It isn't a problem with the URL, it is valid and works on desktop and mobile. This method was also used in another non-async class so I know it works there. My guess is that it is an async issue. This may be a stupid question with a simple answer, but any help is greatly appreciated!
public class getRandom extends AsyncTask<String, Void, String> {
private static final String REQUEST_METHOD = "GET";
private static final int READ_TIMEOUT = 15000;
private static final int CONNECTION_TIMEOUT = 15000;
String result, rawTitle;
// Gets random wiki page and returns text to be loaded into search bar
#Override
protected String doInBackground(String... params){
String randomUrl = "https://en.wikipedia.org/wiki/Special:Random";
String titleApiUrl = "https://en.wikipedia.org/w/api.php?action=query&format=json&titles=";
// Get random title
try {
URL url = new URL(randomUrl);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
//Set method and timeouts
con.setRequestMethod(REQUEST_METHOD);
con.setReadTimeout(READ_TIMEOUT);
con.setConnectTimeout(CONNECTION_TIMEOUT);
// Get status
int status = con.getResponseCode();
// Check for move or redirect and update url
if (status == HttpURLConnection.HTTP_MOVED_TEMP
|| status == HttpURLConnection.HTTP_MOVED_PERM) {
String location = con.getHeaderField("Location");
URL newUrl = new URL(location);
con = (HttpURLConnection) newUrl.openConnection();
}
// Get name of page
rawTitle = con.toString();
int temp = rawTitle.indexOf("wiki/") + 5;
rawTitle = rawTitle.substring(temp);
con.disconnect();
}
catch(IOException e){
e.printStackTrace();
rawTitle = "Sailboats"; // Very random, totally not hard coded result.
}
// Ensure correct title format (use wiki api)
try{
// Get json from api
JSONRequest wikiRequest = new JSONRequest();
String wikiApiJsonString = wikiRequest.execute(titleApiUrl + rawTitle).get();
// Create json object with returned string
JSONObject jsonObj = new JSONObject(wikiApiJsonString);
// Get correct title from json
result = jsonObj.getString("title");
}
catch(ExecutionException | InterruptedException | JSONException e){
e.printStackTrace();
result = "Sailboats"; // Very random, totally not hard coded result.
}
return result;
}
protected void onPostExecute(String result){
super.onPostExecute(result);
}
}

By default, async tasks all run on the same thread. So it won't actually start a second task until yours finishes. Your options are:
1)Call executeOnExecutor instead of execute and tell it to use a new thread.
2)Architect your code such that you can make the request on this thread directly. You're already on a thread, no reason to launch a new one.
3)Write your code such as you don't need to call .get().

Passing entities string using Google NLP API to Main Activity (Android)

I was able to pass a string (a sentence) to Google's NLP API (configured in a separate class called NLPService.java) from my Main Activity Class, but I want to be able to return the result (a certain entity string) from the NLPService Class back to my Main Activity for further processing. Is it possible for me to pass the entities string back to my Main Activity? In Android Studio, I have created a NLPService.java with the following code:
//New NLP Model
public void analyzeText(String textToAnalyze) {
Document doc = new Document();
doc.setContent(textToAnalyze)
.setType("PLAIN_TEXT");
final String[] result = new String[1];
if (textToAnalyze != null && !doc.isEmpty()) {
doc.setContent(textToAnalyze);
//Config request to be sent to Google NLP
Features features = new Features();
features.setExtractEntities(true);
final AnnotateTextRequest request = new AnnotateTextRequest();
request.setDocument(doc);
request.setFeatures(features);
AsyncTask.execute(new Runnable() {
public void run() {
try {
returnResponse(NLPService.documents().annotateText(request).execute());
result[0] = returnResponse(NLPService.documents().annotateText(request).execute());
Log.i("getAsyncResponse", "RESULT: " + result[0]);
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
}
public String returnResponse(AnnotateTextResponse response) {
final List<Entity> entityList = response.getEntities();
String entities = "";
for (Entity entity : entityList) {
entities += "\n" + entity.getName().toUpperCase() + " " + entity.getType();
}
return entities;
}
`

The common approach will be using Broadcast (LocalBroadcastManager) to pass the data you intended to send from service to any activity.
Example of Previous post
Or you can use SharedPreferences which is unlikely.

Custom API in Azure APP Serivce examples searched for Android Client

I need a working example for a custom API for Microsoft Azure App Service.
I could not get any useful or working information/examples for that, or they just show each time different approaches which are outdated?!?!
For now I have a working table controller which gets information from database and returns it back to my Android client. Now I need to define a custom API Controller to get a string back. In the examples they are all sending an object to the service in order to get an object back. I do not want to send anything to the API, just retrieve some information back from a GET Request.
Regards

// EDIT - Added / edited client / server code to Post a String.
You can use the following code to do a GET request on the auto generated API controller Visual Studio creates (ValuesController).
private void getStringFromAzure() throws MalformedURLException {
// Create the MobileService Client object and set your backend URL
String yourURL = "https://yourApp.azurewebsites.net/";
MobileServiceClient mClient = new MobileServiceClient(yourURL, this);
// Your query pointing to yourURL/api/values
ListenableFuture<JsonElement> query = mClient.invokeApi("values", null, GetMethod, null);
// Callback method
Futures.addCallback(query, new FutureCallback<JsonElement>() {
#Override
public void onSuccess(JsonElement jsonElement) {
// You are expecting a String you can just output the result.
final String result = jsonElement.toString();
// Since you are on a async task, you need to show the result on the UI thread
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(mContext, result, Toast.LENGTH_LONG).show();
}
});
}
#Override
public void onFailure(Throwable throwable) {
Log.d(TAG, "onFailure: " + throwable.getMessage());
}
});
}
public void sendString(final String someString) throws MalformedURLException {
// Your query pointing to /api/values/{String}
ListenableFuture<JsonElement> query = mClient.invokeApi("values/" + someString, null, PostMethod, null);
// Callback method
Futures.addCallback(query, new FutureCallback<JsonElement>() {
#Override
public void onSuccess(JsonElement jsonElement) {
// You are expecting a String you can just output the result.
final String result = jsonElement.toString();
}
#Override
public void onFailure(Throwable throwable) { }
});
}
The backend API: (ValuesController)
{
// Use the MobileAppController attribute for each ApiController you want to use
// from your mobile clients
[MobileAppController]
public class ValuesController : ApiController
{
// GET api/values
public string Get()
{
return "Hello World!";
}
// POST api/values/inputString
public string Post(string inputString)
{
return inputString;
}
}
}
You can also send parameters along in the following way:
List<Pair<String, String>> parameters = new ArrayList<>();
parameters.add(new Pair<>("name", "John"));
parameters.add(new Pair<>("password", "fourwordsalluppercase"));
ListenableFuture<JsonElement> query = client.invokeApi("yourAPI", PostMethod, parameters);
Or as json in the body:
JsonObject body = new JsonObject();
body.addProperty("currentPassword", currentPassword);
body.addProperty("password", password);
body.addProperty("confirmPassword", confirmPassword);
ListenableFuture<JsonElement> query = mClient.invokeApi("yourAPI", body, PostMethod, null);

Based on my understanding, I think there are two parts in your question which include as below. And I think you can separately refer to two sections to get the answers and write your own example.
How to define a custom API on Azure Mobile App to retrieve data from database? Please refer to the section Custom APIs to know how to do with Azure Mobile App backend.
How to call a custom API from Android App? Please refer to the section How to: Call a custom API to know how to do with Android SDK.