I have a code in my android app:
homes=Get_HomeList(this, progressBar, view, mMap,MapsActivity.this);
Log.v(TAG, "onMapReady: "+homes.size());
Get_HomeList is a function that fetches data from back end using asynchronous okhhttp call.
Inside this function I have onsuccessful method that is the place I have access to list of homes that has just been fetched.
However I need homes list outside of this function. but this line
Log.v(TAG, "onMapReady: "+homes.size());
gives me null for homes; I guess it is because it is running in parallel thread that has not seen home results yet.
Now my question is that how can handle this and be able to see fetched data outside Get_HomList function? Inside this function it looks like this:
#Override
public void onResponse(Call call, Response response) throws IOException {
if (response.isSuccessful()) {
try {
String responsedata = response.body().string();
homes= extractHomesUpdateMap(responsedata,mMap,mapsActivity);
} catch (IOException e) {
e.printStackTrace();
}
} else {
}
Is there a way that when loading is successful and finished I can pass the results outside of Get_HomeList?Or in General how we can deal with this cases?
I am making a simple Android Wear app to control my thermostats, and I'm sending POST requests with Volley to control them. Everything works great in the Android Wear simulator (the request works), but, while the app does load on my Moto 360, the volley request gets called but invariably times out.
Why could my volley request be failing on my watch but working on the simulator? Other apps' requests succeed on my watch (for example, the built-in weather app can load up weather data in about 3 seconds). And, the weirdest part: I had the app working (successfully making volley requests) on my watch, and, about a day after I installed it to my watch from Android Studio, it suddenly stopped loading data for no apparent reason.
What I've tried so far:
I have requested the Internet permission in my manifest.xml.
I have increased the timeout to 30 seconds (see my code below), which didn't change anything.
I have tried tethering my computer and the simulator to my phone's connection via Bluetooth (to replicate the Bluetooth connection my physical watch has to my phone), and the simulator made the request successfully still (albeit with a two-second delay), ruling out the possibility of Bluetooth being too slow.
I made sure the API level is low enough for my Marshmallow-running watch (my watch and the app are both API level 23).
I tried doing a quick test request to Google before the request to the company's servers with my thermostat data, and while the Google request returns the site's HTML code in the simulator, it times out on my watch (thirty seconds after the request is initiated).
I tried putting some dummy data into the recycler view data should be loaded into, and the dummy data indeed showed up, ruling out that the recycler view is broken.
I deleted the app from my watch and reinstalled it, and deleted the companion from my phone, reinstalled it, and deleted it again, all to no avail.
A lengthy chat with Google Support did not produce anything meaningful.
Here's my code (from my main view's adapter):
public void refreshThermostatsRecyclerView(RequestQueue queue) {
String url = "https://mobile.skyport.io:9090/login"; // login call to the thermostats server Skyport
Log.w("myApp", "Starting /login call to Skyport"); // this gets called on simulator and watch
// Request a string response from the provided URL.
StringRequest stringRequest = new StringRequest(Request.Method.POST, url,
Response.Listener<String>() {
#Override
public void onResponse(String response) {
// Display the response string.
Log.w("myApp", "Response is: " + response); // this gets called on the simulator but not the watch
try {
// there's some code to parse the data.
} catch (JSONException e) {
Log.w("myApp", "catching an error parsing the json."); // never gets called.
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.w("myApp", "Skyport request didn't work! " + error); // this always gets called on the watch, with the error being a timeout error (com.Android.Volley.timeouterror) but never gets called in the simulator
}
}) {
#Override
public Map<String, String> getHeaders() throws AuthFailureError {
Map<String, String> m = new HashMap<>();
m.put("Referer", "app:/VenstarCloud.swf");
// here I put some more headers
return m;
}
#Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> m = new HashMap<>();
m.put("version", "3.0.5");
m.put("email", userEmail);
m.put("password", userToken);
return m;
}
};
// Add the request to the RequestQueue.
int socketTimeout1 = 30000; // times out 30 seconds after the request starts on the watch
RetryPolicy policy1 = new DefaultRetryPolicy(socketTimeout1, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
stringRequest.setRetryPolicy(policy1);
queue.add(stringRequest);
}
Which is called from the onCreate() method in my Main Activity with this code:
RequestQueue queue = Volley.newRequestQueue(this);
refreshThermostatsRecyclerView(queue);
If you'd like to view the logs created by running this in the simulator and on the watch, they're on Google Drive here.
Edit 1: A reboot of my watch fixes the issue temporarily and allows the watch to make HTTP Requests again, but it breaks again once the watch disconnects from Bluetooth, connects to WiFi, disconnects from WiFi, and reconnects to Bluetooth (so it breaks every time I go across my apartment without my phone and then return).
Edit 2: I switched the volley requests all over to HTTPURLConnection Requests in an Async thread, and the same issues occur as with volley.
tl;dr: My app's Volley requests are working in the simulator but not on my Android Wear watch anymore (though Play Store-downloaded apps' similar requests work), how can I get a volley request to work again on my app on the watch?
As per these two conversations below, it seems that WiFi connectivity only allows Android Wear to connect to a phone over WiFi and not directly to the Internet. However, Android Wear 2.0 lets you use regular network APIs.
Direct internet connection on Android Wear?
Does Android Wear support direct access to the Internet?
So, for Android Wear 2.0+ Volley requests from wearable app should work.
If you want to use Android Wear <2.0, then:
On Wearable, in onCreate() add a key that indicates whether the phone should start collecting data.
PutDataMapRequest putDataMapReq = PutDataMapRequest.create("/shouldStart");
putDataMapReq.getDataMap().putBoolean(SHOULD_START_KEY, true);
PutDataRequest putDataReq = putDataMapReq.asPutDataRequest();
PendingResult pendingResult = Wearable.DataApi.putDataItem(mGoogleApiClient, putDataReq);
On phone, in onDataChanged, check if wearable wants to start collecting data. If yes, start Volley request.
for (DataEvent event : dataEvents) {
if (event.getType() == DataEvent.TYPE_CHANGED) {
// DataItem changed
DataItem item = event.getDataItem();
if (item.getUri().getPath().compareTo("/shouldStart") == 0) {
DataMap dataMap = DataMapItem.fromDataItem(item).getDataMap();
boolean shouldStart = dataMap.getBoolean(SHOULD_START_KEY));
if(shouldStart) {
Volley.newRequestQueue(this).add(request);
}
}
} else if (event.getType() == DataEvent.TYPE_DELETED) {
// DataItem deleted
}
}
Then, your Volley request's onResponse should pass data back to Wearable.
public void onResponse(String response) {
PutDataMapRequest putDataMapReq = PutDataMapRequest.create("/data");
putDataMapReq.getDataMap().putString(DATA_KEY, true);
PutDataRequest putDataReq = putDataMapReq.asPutDataRequest();
PendingResult pendingResult = Wearable.DataApi.putDataItem(mGoogleApiClient, putDataReq);
}
Finally, you can access data in your Wearable using onDataChanged and store it in your model for passing it onto adapter:
for (DataEvent event : dataEvents) {
if (event.getType() == DataEvent.TYPE_CHANGED) {
// DataItem changed
DataItem item = event.getDataItem();
if (item.getUri().getPath().compareTo("/data") == 0) {
DataMap dataMap = DataMapItem.fromDataItem(item).getDataMap();
parseAndpassToAdapter(dataMap.getString(DATA_KEY));
}
} else if (event.getType() == DataEvent.TYPE_DELETED) {
// DataItem deleted
}
}
You'll need Wearable.API to implement this and your class should implement DataApi.DataListener. For more information getting started, refer to Accessing the Wearable Data Layer and Syncing Data Items
Hope this helps.
I am also using volley on an Android wear app I built and I am running it on a Moto 360, I have run into the same problem a couple o times. Try restarting the device. Go to Settings > Restart. It sounds silly but it has worked for me.
You could try an alternative to volley if you can rule out the connection as the problem:
compile 'com.android.support:appcompat-v7:23.1.1'
compile 'com.android.support:support-v4:23.1.0'
compile 'com.android.support:design:23.1.0'
compile 'com.google.code.gson:gson:2.2.4'
compile 'com.google.api-client:google-api-client:1.20.0'
The versions are important.
Then to your request:
Map<String, String> contentParams = new HashMap<>();
InputStream is = null;
NetHttpTransport transport = null;
HttpRequest request = null;
HttpResponse resp = null;
HttpHeaders headers = new HttpHeaders();
JSONObject json = null;
try {
transport = new NetHttpTransport();
HttpRequestFactory factory = transport.createRequestFactory();
request = factory.buildPostRequest(new GenericUrl(url), null);
contentParams = getContentParameters();
headers.putAll(getHeaderParameters());
request.setHeaders(headers);
request.getUrl().putAll(contentParams);
resp = request.execute();
is = resp.getContent();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (is != null) {
string = getJSONFromInputStream(is);
json = new JSONObject(string);
}
} catch (Exception e) {
e.printStackTrace();
}
}
transport.shutdown();
protected Map<String, String> getContentParameters() {
Map<String, String> m = new HashMap<>();
m.put("version", "3.0.5");
m.put("email", userEmail);
m.put("password", userToken);
return m;
}
protected Map<String, String> getHeaderParameters() {
Map<String, String> m = new HashMap<>();
m.put("Referer", "app:/VenstarCloud.swf");
return m;
}
protected String getJSONFromInputStream(InputStream is) {
if (is == null)
throw new NullPointerException();
//instantiates a reader with max size
BufferedReader reader = new BufferedReader(new InputStreamReader(is), 8 * 1024);
StringBuilder sb = new StringBuilder();
try {
//reads the response line by line (and separates by a line-break)
String line;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
//closes the inputStream
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}
Then just execute your code from a thread/asynctask/have it delay your frontend slightly
Edit:
Just in case there is a problem with appending a map:
for (Entry<String, String> entry : getHeaderParameters()) {
headers.put(entry.getKey(), entry.getValue());
}
for (Entry<String, String> entry : getContentParameters()) {
request.getUrl().put(entry.getKey(), entry.getValue());
}
Also as another note, make sure to change the return type from void on both those methods to Map
Is this not just the case of when the watch is connected to the phone via bluetooth the internet will not work, as wifi is turned off. If the watch is using wifi to connect to the phone then it will work.
I'm working on wear 2.0 app and just turn blueooth off on my phone for my watch to get internet connection.
I am trying to save some user data internally. Ideally, I would like to save
String[] text;
String name;
String file_name;
Together in one (for lack of a better term) package, and then use all saves name's with the other data to populate another activities listView, where I can load the saved information. Here is the code I am trying to use to save the information:
Button fileName;
fileName = (Button) findViewById(R.id.save_text);
fileName.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
outputStream = openFileOutput(file_name, Context.MODE_APPEND);
ObjectOutputStream phone_save = new ObjectOutputStream(outputStream);
phone_save.writeObject(name);
phone_save.writeObject(text);
Log.i("Save", "Files saved");
} catch (Exception e) {
e.printStackTrace();
}
}
});
Then this is the code that tries to get that saved information(for now I just have it trying to set the text of a text View, not a listView yet)
Button load;
TextView load_text
load = (Button) findViewById(R.id.load);
load.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
fin = openFileInput(file_name);
ObjectInputStream ois = new ObjectInputStream(fin);
String[] Loaded_Text = (String[]) ois.readObject();
ois.close();
load_text.setText(Html.fromHtml(Arrays.toString(Loaded_Text)));
} catch (Exception e) {
e.printStackTrace();
}
}
});
I am having a problem saving and loading the data, no log statement appears when I push the filename button, and nothing appears in the textView when I push the load Button. Essentially none of it works, and I have absolutely no clue how to fix it. I'm sure this code is a mess, but this is really my first time working with storage. Thanks everyone!
Posting as an answer you can accept.
Did you consider using SharedPreferences? I think that would be a lot simpler than writing and reading files. You store key-value pairs, so any piece of data needs a unique string to identify it.
prefs.putString("key1",stringValue);
prefs.putString("key2", anotherStringValue);
You would just need to convert your string array to and from a string.
You should consider implementing database support for your application. Database data is easier to maintain, in contrast to SharedPreferences. Here is a good tutorial that explains how to implement an SQLite database.
In my app, I create a SQLite database. Then I populate it with JSON data fetched from a URL using an instance of the HttpAsyncTask class in my main activity. That works fine, but I also want to update the database. New data (one row in the database) is added to the URL page once per day, and I want to implement a "synchronize" button in the app that updates the database with only the new information. Could I get some advice on how to do this? My HttpAsyncTask is below, if that helps - I'm thinking I might need an if/else clause in the onPostExecute() method that adds all the rows only if the database is getting created for the first time. I thought about trying to put an HttpAsyncTask class in my DatabaseHelper, but that doesn't really make sense.
private class HttpAsyncTask extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String...urls) {
return GET(urls[0]);
}
#Override
protected void onPostExecute(String result) {
try {
JSONObject main = new JSONObject(result);
JSONObject body = main.getJSONObject("body");
JSONArray measuregrps = body.getJSONArray("measuregrps");
// get measurements for date, unit, and value (weight)
for (int i = 0; i < measuregrps.length(); i++) {
JSONObject row = measuregrps.getJSONObject(i);
// a lot of getting & parsing data happens
db.addEntry(new Entry(date, weight, null, null));
//adds all the lines every time this is run, but I only want to add all
//the lines once and then add new rows one by one from there
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
public static String GET(String url) {
InputStream is = null;
String result = "";
try {
HttpClient client = new DefaultHttpClient();
HttpGet get = new HttpGet(url);
HttpResponse httpResponse = client.execute(get);
is = httpResponse.getEntity().getContent();
if (is != null)
result = convertInputStream(is);
else
result = "Did not work!";
} catch (Exception e) {
Log.d("input stream", e.getLocalizedMessage());
}
return result;
}
private static String convertInputStream(InputStream is) throws IOException {
StringBuilder builder = new StringBuilder();
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
String line = "";
while((line = reader.readLine()) != null)
builder.append(line);
is.close();
return builder.toString();
}
Your implementation totally depends on the project requirements.
If there are continuously changes over the server, the right way to implement the synchronization process is:
1.
Implement the sync process, which works totally in background. This sync will be customized to call specific API calls/Service classes which will be required to sync.
2.
Server will prompt the mobile client for the data change.
3.
To get server updates, A continuously running service/Sync at some predefined intervals will be run and checks for the updates or implements the GCM.
Sync Adapter would be the best for the sync services.
Ohh, also don't forget to apply the content provider, as database calls would be concurrent from UI and background both.
Hope it may help to decide.
You have to check there is similar data available in the table if yes update the table and if no insert new data to table
I'm writing an android app I use a background thread to pull a JSONArray from a web service. I then need to interact with that JSONArray inside the main activity. Here's what I'm doing now:
public class MainActivity extends Activity {
JSONArray stories;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new getAll().execute();
// try {
System.out.println("stories.length());
// } catch (JSONException e) {
// TODO Auto-generated catch block
// e.printStackTrace();
//}
}
And the background thread:
private class getAll extends AsyncTask <Void, Void, JSONArray> {
private static final String url = "http://10.0.2.2:8080/CalibServer/webresources/storypkg.story/";
#Override
protected JSONArray doInBackground(Void... params) {
//set up client and prepare request object to accept a json object
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(url);
httpget.addHeader("accept", "application/json");
HttpResponse response;
String resprint = new String();
try {
response = httpclient.execute(httpget);
// Get the response entity
HttpEntity entity = response.getEntity();
if (entity != null) {
// get entity contents and convert it to string
InputStream instream = entity.getContent();
String result= convertStreamToString(instream);
resprint = result;
// construct a JSON object with result
stories =new JSONArray(result);
// Closing the input stream will trigger connection release
instream.close();
}
}
catch (ClientProtocolException e) {System.out.println("CPE"); e.printStackTrace();}
catch (IOException e) {System.out.println("IOE"); e.printStackTrace();}
catch (JSONException e) { System.out.println("JSONe"); e.printStackTrace();}
System.out.println("FUCKYEAHBG: " + resprint);
// stories = object;
return stories;
}
My problem is that I'm getting a NullPointerException at the call to
System.out.println("stories.length());
It's acting like a didn't initialize the stories array, but should't that have been taken care of by the background thread (at the line: stories =new JSONArray(result); ) before that call is ever made?
I have a feeling this is because of the threading - perhaps there is another step I have to take to update the main activity after the AsyncTask runs?
You're initializing the variable in a background thread. That means that the line
System.out.println(stories.length());
is executed in parallel with the code initializing the variable. That thus means that there is a huge chance that the background thread has not had the time to initialize the variable yet when this line is executed.
Your code is similar to the following situation: you have an empty cup in front of you, and ask someone to go make some coffee and to fill your cup. And immediately after asking, you start drinking. There will be no coffee inside the cup, obviously.
Re-read the android documentation on how to execute asynchronous tasks.
You can't rely on stories to be initialized when a separate Thread that runs parallel to the UI Thread initializes and updates stories.
perhaps there is another step I have to take to update the main
activity after the AsyncTask runs?
onPostExecute() of the AsyncTask. Do whatever UI updates you need there. Since getAll is already a private inner class, you have full access to the Activity. You already return stories off to that (unoverriden) method, so this should be a minor change.
#Override
protected void onPostExecute (JSONArray stories)
{
//use the now initialized stories
}