Develop Reference

Is it possible to send notification from android device to all android devices using firebase without 3rd party server [duplicate]

I have been trying to read the official docs and guides about how to send message from one device to another. I have saved registration token of both devices in the Real Time Database, thus I have the registration token of another device.
I have tried the following way to send the message
RemoteMessage message = new RemoteMessage.Builder(getRegistrationToken())
.setMessageId(incrementIdAndGet())
.addData("message", "Hello")
.build();
FirebaseMessaging.getInstance().send(message);
However this is not working. The other device doesn't receive any message. I am not even sure, if I can use upstream message sending to conduct device to device communication.
PS: I just want to know if device-to-device messaging is possible using FCM? If yes, then is the code I used have some issue? If yes, then what is the correct way.
Update:
My question was to ask whether device to device messaging without using any separate server other than firebase could messaging is possible or not, if yes than how, since there's no documentation about it. I do not understand what is left to explain here? Anyways I got the answer and will update it as an answer once the question gets reopened.

Firebase has two features to send messages to devices:
the Notifications panel in your Firebase Console allows you to send notifications to specific devices, groups of users, or topics that users subscribed to.
by calling Firebase Cloud Messaging API, you can send messages with whatever targeting strategy you prefer. Calling the FCM API requires access to your Server key, which you should never expose on client devices. That's why you should always run such code on an app server.
The Firebase documentation shows this visually:
Sending messages from one device directly to another device is not supported through the Firebase Cloud Messaging client-side SDKs.
Update: I wrote a blog post detailing how to send notifications between Android devices using Firebase Database, Cloud Messaging and Node.js.
Update 2: You can now also use Cloud Functions for Firebase to send messages securely, without spinning up a server. See this sample use-case to get started. If you don't want to use Cloud Functions, you can run the same logic on any trusted environment you already have, such as your development machine, or a server you control.

Warning There is a very important reason why we don't mention this approach anywhere. This exposes your server key in the APK that
you put on every client device. It can (and thus will) be taken from
there and may lead to abuse of your project. I highly recommend
against taking this approach, except for apps that you only put on
your own devices. – Frank van Puffelen
Ok, so the answer by Frank was correct that Firebase does not natively support device to device messaging. However there's one loophole in that. The Firebase server doesn't identify whether you have send the request from an actual server or are you doing it from your device.
So all you have to do is send a Post Request to Firebase's messaging server along with the Server Key. Just keep this in mind that the server key is not supposed to be on the device, but there's no other option if you want device-to-device messaging using Firebase Messaging.
I am using OkHTTP instead of default way of calling the Rest API. The code is something like this -
public static final String FCM_MESSAGE_URL = "https://fcm.googleapis.com/fcm/send";
OkHttpClient mClient = new OkHttpClient();
public void sendMessage(final JSONArray recipients, final String title, final String body, final String icon, final String message) {
new AsyncTask<String, String, String>() {
#Override
protected String doInBackground(String... params) {
try {
JSONObject root = new JSONObject();
JSONObject notification = new JSONObject();
notification.put("body", body);
notification.put("title", title);
notification.put("icon", icon);
JSONObject data = new JSONObject();
data.put("message", message);
root.put("notification", notification);
root.put("data", data);
root.put("registration_ids", recipients);
String result = postToFCM(root.toString());
Log.d(TAG, "Result: " + result);
return result;
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String result) {
try {
JSONObject resultJson = new JSONObject(result);
int success, failure;
success = resultJson.getInt("success");
failure = resultJson.getInt("failure");
Toast.makeText(getCurrentActivity(), "Message Success: " + success + "Message Failed: " + failure, Toast.LENGTH_LONG).show();
} catch (JSONException e) {
e.printStackTrace();
Toast.makeText(getCurrentActivity(), "Message Failed, Unknown error occurred.", Toast.LENGTH_LONG).show();
}
}
}.execute();
}
String postToFCM(String bodyString) throws IOException {
RequestBody body = RequestBody.create(JSON, bodyString);
Request request = new Request.Builder()
.url(FCM_MESSAGE_URL)
.post(body)
.addHeader("Authorization", "key=" + SERVER_KEY)
.build();
Response response = mClient.newCall(request).execute();
return response.body().string();
}
I hope Firebase will come with a better solution in future. But till then, I think this is the only way. The other way would be to send topic message or group messaging. But that was not in the scope of the question.
Update:
The JSONArray is defined like this -
JSONArray regArray = new JSONArray(regIds);
regIds is a String array of registration ids, you want to send this message to. Keep in mind that the registration ids must always be in an array, even if you want it to send to a single recipient.

I have also been using direct device to device gcm messaging in my prototype. It has been working very well. We dont have any server. We exchange GCM reg id using sms/text and then communicate using GCM after that. I am putting here code related to GCM handling
**************Sending GCM Message*************
//Sends gcm message Asynchronously
public class GCM_Sender extends IntentService{
final String API_KEY = "****************************************";
//Empty constructor
public GCM_Sender() {
super("GCM_Sender");
}
//Processes gcm send messages
#Override
protected void onHandleIntent(Intent intent) {
Log.d("Action Service", "GCM_Sender Service Started");
//Get message from intent
String msg = intent.getStringExtra("msg");
msg = "\"" + msg + "\"";
try{
String ControllerRegistrationId = null;
//Check registration id in db
if(RegistrationIdAdapter.getInstance(getApplicationContext()).getRegIds().size() > 0 ) {
String controllerRegIdArray[] = RegistrationIdAdapter.getInstance(getApplicationContext()).getRegIds().get(1);
if(controllerRegIdArray.length>0)
ControllerRegistrationId = controllerRegIdArray[controllerRegIdArray.length-1];
if(!ControllerRegistrationId.equalsIgnoreCase("NULL")){
// 1. URL
URL url = new URL("https://android.googleapis.com/gcm/send");
// 2. Open connection
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
// 3. Specify POST method
urlConnection.setRequestMethod("POST");
// 4. Set the headers
urlConnection.setRequestProperty("Content-Type", "application/json");
urlConnection.setRequestProperty("Authorization", "key=" + API_KEY);
urlConnection.setDoOutput(true);
// 5. Add JSON data into POST request body
JSONObject obj = new JSONObject("{\"time_to_live\": 0,\"delay_while_idle\": true,\"data\":{\"message\":" + msg + "},\"registration_ids\":[" + ControllerRegistrationId + "]}");
// 6. Get connection output stream
OutputStreamWriter out = new OutputStreamWriter(urlConnection.getOutputStream());
out.write(obj.toString());
out.close();
// 6. Get the response
int responseCode = urlConnection.getResponseCode();
BufferedReader in = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null){
response.append(inputLine);
}
in.close();
Log.d("GCM getResponseCode:", new Integer(responseCode).toString());
}else{
Log.d("GCM_Sender:","Field REGISTRATION_TABLE is null");
}
}else {
Log.d("GCM_Sender:","There is no Registration ID in DB ,please sync devices");
}
} catch (Exception e) {
e.printStackTrace();
//MessageSender.getInstance().sendMessage(msg, Commands.SMS_MESSAGE);
}
}
//Called when service is no longer alive
#Override
public void onDestroy() {
super.onDestroy();
//Do a log that GCM_Sender service has been destroyed
Log.d("Action Service", "GCM_Sender Service Destroyed");
}
}
**************Receiving GCM Message*************
public class GCM_Receiver extends WakefulBroadcastReceiver {
public static final String RETRY_ACTION ="com.google.android.c2dm.intent.RETRY";
public static final String REGISTRATION ="com.google.android.c2dm.intent.REGISTRATION";
public SharedPreferences preferences;
//Processes Gcm message .
#Override
public void onReceive(Context context, Intent intent) {
ComponentName comp = new ComponentName(context.getPackageName(),
GCMNotificationIntentService.class.getName());
//Start GCMNotificationIntentService to handle gcm message asynchronously
startWakefulService(context, (intent.setComponent(comp)));
setResultCode(Activity.RESULT_OK);
/*//Check if DatabaseService is running .
if(!DatabaseService.isServiceRunning) {
Intent dbService = new Intent(context,DatabaseService.class);
context.startService(dbService);
}*/
//Check if action is RETRY_ACTION ,if it is then do gcm registration again .
if(intent.getAction().equals(RETRY_ACTION)) {
String registrationId = intent.getStringExtra("registration_id");
if(TextUtils.isEmpty(registrationId)){
DeviceRegistrar.getInstance().register(context);
}else {
//Save registration id to prefs .
preferences = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = preferences.edit();
editor.putString("BLACKBOX_REG_ID",registrationId);
editor.commit();
}
} else if (intent.getAction().equals(REGISTRATION)) {
}
}
}
//Processes gcm messages asynchronously .
public class GCMNotificationIntentService extends IntentService{
public static final int NOTIFICATION_ID = 1;
private NotificationManager mNotificationManager;
String gcmData;
private final String TAG = "GCMNotificationIntentService";
//Constructor with super().
public GCMNotificationIntentService() {
super("GcmIntentService");
}
//Called when startService() is called by its Client .
//Processes gcm messages .
#Override
protected void onHandleIntent(Intent intent) {
Log.d("GCMNotificationIntentService", "GCMNotificationIntentService Started");
Bundle extras = intent.getExtras();
//Get instance of GoogleCloudMessaging .
GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
//Get gcm message type .
String messageType = gcm.getMessageType(intent);
if (!extras.isEmpty()) {
if (GoogleCloudMessaging.MESSAGE_TYPE_SEND_ERROR
.equals(messageType)) {
sendNotification("Send error: " + extras.toString());
} else if (GoogleCloudMessaging.MESSAGE_TYPE_DELETED
.equals(messageType)) {
sendNotification("Deleted messages on server: "
+ extras.toString());
} else if (GoogleCloudMessaging.MESSAGE_TYPE_MESSAGE
.equals(messageType)) {
Log.i(TAG, "Completed work # " + SystemClock.elapsedRealtime());
gcmData = extras.getString("message");
Intent actionService = new Intent(getApplicationContext(),Action.class);
actionService.putExtra("data", gcmData);
//start Action service .
startService(actionService);
//Show push notification .
sendNotification("Action: " + gcmData);
//Process received gcmData.
Log.d(TAG,"Received Gcm Message from Controller : " + extras.getString("message"));
}
}
GCM_Receiver.completeWakefulIntent(intent);
}
//Shows notification on device notification bar .
private void sendNotification(String msg) {
mNotificationManager = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE);
Intent notificationIntent = new Intent(this, BlackboxStarter.class);
//Clicking on GCM notification add new layer of app.
notificationIntent.setFlags( Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
PendingIntent contentIntent = PendingIntent.getActivity(this, 0,notificationIntent, PendingIntent.FLAG_CANCEL_CURRENT);
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(
this).setSmallIcon(R.drawable.gcm_cloud)
.setContentTitle("Notification from Controller")
.setStyle(new NotificationCompat.BigTextStyle().bigText(msg))
.setContentText(msg);
mBuilder.setContentIntent(contentIntent);
mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
//Play default notification
try {
Uri notification = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
Ringtone r = RingtoneManager.getRingtone(getApplicationContext(), notification);
r.play();
} catch (Exception e) {
e.printStackTrace();
}
}
//Called when service is no longer be available .
#Override
public void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
Log.d("GCMNotificationIntentService", "GCMNotificationIntentService Destroyed");
}
}

According to the new documentation which was updated on October 2, 2018 you must send post request as below
https://fcm.googleapis.com/fcm/send
Content-Type:application/json
Authorization:key=AIzaSyZ-1u...0GBYzPu7Udno5aA //Server key
{
"to": "sent device's registration token",
"data": {
"hello": "message from someone",
}
}
To get device's registration token extend FirebaseMessagingService and override onNewToken(String token)
For more info refer to doc https://firebase.google.com/docs/cloud-messaging/android/device-group

I am late but above solutions has helped me to write down this simple answer, you can send your message directly to android devices from android application, here is the simple implementation I have done and it works great for me.
compile android volley library
compile 'com.android.volley:volley:1.0.0'
Just copy paste this simple function ;) and your life will become smooth just like knife in butter. :D
public static void sendPushToSingleInstance(final Context activity, final HashMap dataValue /*your data from the activity*/, final String instanceIdToken /*firebase instance token you will find in documentation that how to get this*/ ) {
final String url = "https://fcm.googleapis.com/fcm/send";
StringRequest myReq = new StringRequest(Request.Method.POST,url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Toast.makeText(activity, "Bingo Success", Toast.LENGTH_SHORT).show();
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(activity, "Oops error", Toast.LENGTH_SHORT).show();
}
}) {
#Override
public byte[] getBody() throws com.android.volley.AuthFailureError {
Map<String, Object> rawParameters = new Hashtable();
rawParameters.put("data", new JSONObject(dataValue));
rawParameters.put("to", instanceIdToken);
return new JSONObject(rawParameters).toString().getBytes();
};
public String getBodyContentType()
{
return "application/json; charset=utf-8";
}
#Override
public Map<String, String> getHeaders() throws AuthFailureError {
HashMap<String, String> headers = new HashMap<String, String>();
headers.put("Authorization", "key="+YOUR_LEGACY_SERVER_KEY_FROM_FIREBASE_CONSOLE);
headers.put("Content-Type","application/json");
return headers;
}
};
Volley.newRequestQueue(activity).add(myReq);
}
Note
If you want to send message to topics so you can change parameter instanceIdToken to something like /topics/topicName.
For groups implementation is the same but you just need to take care of parameters. checkout Firebase documentation and you can pass those parameters.
let me know if you face any issue.

Second HttpURLConnection is failing

I have a ListView that onLongClick it calls a method that is supposed to go out to a website, pull a jsonArray from it and then return information that is pulled from the array. However, when it calls the HttpURLConnection.connect() method it fails and goes to the catch block. When I use the getMessage() message on the exception it only returns Null. This is the second time in this program that I've connected to a URL in this same way and it works the first time perfectly. What could be causing this issue?
Here is the code for when the method is called:
list.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
public boolean onItemLongClick(AdapterView<?> a, View v, int pos, long id) {
String trainNum = list.getItemAtPosition(pos).toString();
String info = "hello";
try {
info = getCurrentTrainInfo(trainNum);
}catch(Exception e){
info = e.getMessage();
if(info == null)
info = "info is null";
tv.setText(info);
}
Toast.makeText(getApplicationContext(), info, Toast.LENGTH_LONG).show();
return true;
}
}
);
And here is the method getCurrentTrainInfo that is called in the try block above:
public String getCurrentTrainInfo(String num) throws IOException{
String sURL = "http://www3.septa.org/hackathon/RRSchedules/" + num;
URL url = new URL(sURL);
HttpURLConnection request2 = (HttpURLConnection) url.openConnection();
request2.connect();
JsonParser jp = new JsonParser();
JsonElement root = jp.parse(new InputStreamReader((InputStream) request.getContent()));
JsonArray rootArr = root.getAsJsonArray();
int i = 0;
String acTime = "";
String station = rootArr.get(i).getAsJsonObject().get("station").getAsString();
String schTime = rootArr.get(i).getAsJsonObject().get("sched_tm").getAsString();
String esTime = rootArr.get(i).getAsJsonObject().get("est_tm").getAsString();
tv.setText(station);
String info = "Current Station: " + station + "\nScheduled leave time: " + schTime + "\nEstimated leave time: " + esTime;*/
return info;
}
Is there anything I can do to fix this problem?

I see your request is being made ​​in the UI thread, you mentioned that in another moment used this same way and it worked, I believe this may have happened when you ran your application on a device/emulator with a version of Android prior to 3.0.
Within an Android application you should avoid performing long
running operations on the user interface thread. This includes file
and network access. StrictMode allows to setup policies in your
application to avoid doing incorrect things. As of Android 3.0
(Honeycomb) StrictMode is configured to crash with a
NetworkOnMainThreadException exception, if network is accessed in
the user interface thread.
You can create a AsyncTasks class and move the call request to it.

Updating a ContentProvider's underlying SQLite database from internet resource

I have a implemented a ContentProvider to serve up a list of geographical locations from an underlying SQLite database.
These locations are actually an output from a model and are available online in the form of a simple JSON string; I don't want to keep downloading them every time the app is started, so I want to store them locally in a database and update them at pre-defined intervals (once a day for instance).
My question is, where should I implement the downloading and parsing code? Should it be part of my ContentProvider implementation? Or part of the SQLiteOpenHelper implementation?
I started to implement it as a public function called updateSiteList in my ContentProvider, but I don't know how to actually call it (the ContentProvider is usually acessed indirectly via CursorLoader)!
I am bit stuck as to how to progress!
Can anyone point me in the right direction?
Thanks!

There are a couple of ways to achieve this.
The two most common ways I use are :-
1) a custom sync adapter.
2) An intent service.
With option 1 you get the benefit of the Android system handling network connection problems and is the recommended approach by the android Developers
With option 2 you get more control over when the data gets downloaded which may or may not be the best time for the user or the Android System.
Either way the solution is the same. At some point in time you will be making, in a background service, an HTTP get request to a url. when your request completes you will need to heck the status of the response and if appropriate you would then make a call to the content provider to wither insert or update your data accordingly. whichever approach you take this part will be the same.
Some further reading for you.
https://sites.google.com/site/andsamples/concept-of-syncadapter-androidcontentabstractthreadedsyncadapter
Be sure to watch that Google I/O video
Regardless of the approach you take, the code to download json and insert to your content provider could look something like this in an IntentService called from either your sync adapter or from somewhere within your app if not using a sync adapter.
public class ServiceInitialiseData extends IntentService {
static final String TAG = "ServiceSyncData";
//ACTION should include application package convention, just to show that this can
//be any string
public static final String SYNC_COMPLETED_ACTION="com.pjmobile.games.fantasyf1.SyncCompleted";
public ServiceInitialiseData() {
super("InitialiseDataService");
}
#Override
protected void onHandleIntent(Intent intent) {
String sJson;
try {
sJson = downloadFromServer("Some parsed url");
int i, x;
boolean res = false;
List <ContentValues> bulkValues = new ArrayList <ContentValues>();
JSONArray entries;
try {
entries = new JSONArray(sJson);
ContentValues cvEntity = null;
JSONObject entity;
x = entries.length();
for (i=0;i<x;i++){
entity = entries.getJSONObject(i).getJSONObject("some_json_key");
bulkValues.add(cvEntity);
}
}
int qCount = getContentResolver().bulkInsert(uri,
(ContentValues[])bulkValues.toArray(new
ContentValues[bulkValues.size()]));
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
private String downloadFromServer(String url) throws ClientProtocolException, IOException {
HttpResponse sJson = getJSONEntityFromURL(this, url);
return EntityUtils.toString(sJson.getEntity());
}
private static HttpResponse getJSONEntityFromURL(Context context, String url) throws ClientProtocolException, IOException {
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(url);
httpget.addHeader("Accept", "application/json");
httpget.addHeader("Content-Type", "application/json; charset=UTF-8");
HttpResponse response;
response = httpclient.execute(httpget);
return response;
}
For the above to work you would have to ode up the bulk insert method of your content provider which could look something like this
#Override
public int bulkInsert(Uri uri, ContentValues[] values) {
final SQLiteDatabase db = mDB.getWritableDatabase();
final int match = sURIMatcher.match(uri);
int numInserted= 0;
// Util.log_debug_message("#### URI MATCH - " + match);
switch(match){
case TEAMS:
numInserted = insertTeams(db, values);
break;
default:
throw new UnsupportedOperationException("unsupported uri: " + uri);
}
getContext().getContentResolver().notifyChange(uri, null, false);
return numInserted;
}
private int insertTeams(SQLiteDatabase db, ContentValues[] values) {
int numInserted = 0;
db.beginTransaction();
try {
//standard SQL insert statement, that can be reused
SQLiteStatement insert =
db.compileStatement(INSERT_OR_REPLACE_STRING + TeamModel.TEAM_TABLE_NAME
+ "(" + TeamModel.COL_SERVER_ID
+ "," + TeamModel.COL_BONUS_RACE_ID
+ "," + TeamModel.COL_POINTS
+ "," + TeamModel.COL_POSITION
+ "," + TeamModel.COL_TEAM_NAME + ")"
+" values " + "(?,?,?,?,?)");
for (ContentValues value : values){
//bind the 1-indexed ?'s to the values specified
insert.bindString(1, value.getAsString(TeamModel.COL_SERVER_ID));
insert.bindString(2, value.getAsString(TeamModel.COL_BONUS_RACE_ID));
insert.bindString(3, value.getAsString(TeamModel.COL_POINTS));
insert.bindString(4, value.getAsString(TeamModel.COL_POSITION));
insert.bindString(5, value.getAsString(TeamModel.COL_TEAM_NAME));
insert.execute();
}
db.setTransactionSuccessful();
numInserted = values.length;
} finally {
db.endTransaction();
db.close();
}
return numInserted;
}
This is not a copy and paste solution. Merely an example stripped out of one of my apps and you should look at each line of code and take great care to understand what is going on.

Read random status from a page using facebook api

I am creating an android app for my facebook page. The app is supposed to display random statuses(not just the recent ones) from the facebook page. Is there anyway I could do this?

I haven't done anything of that kind ever, but I think you can gran some logic from this and get it to work.
Step 1:
Make a call to the Facebook API, get all Status Updates and in a for loop, add them to an ArrayList<String>. For example, Facebook returns its data in JSON format. I am assuming, you already know how to fetch data. You need to parse the "message" tag from the JSON data returned by your Facebook API call.
For example:
ArrayList<String> arrStatusMessage;
for (int i = 0; i < JAFeeds.length(); i++) {
JSONObject JOFeeds = JAFeeds.getJSONObject(i);
if (JOFeeds.has("message")) {
String strStatusMessage = JOFeeds.getString("message");
arrStatusMessage.add(strStatusMessage );
}
}
Step 2:
Once you have your entire set of Facebook Status Messages, you will now need to use a java.util.Random instance.
For example: (Please note: I have not tested this code and it might result in errors. You may have to play around with it a bit to get it to work. :-( )
private static final Random randomGenerator = new Random();
int intRandom = randomGenerator.nextInt(arrStatusMessage.size());
String strRandomStatus = arrStatusMessage.get(intRandom);
Step 3:
Use the strRandomStatus to set it on a TextView.
For example:
TextView txtRanStatus = (TextView) findViewById(R.id.txtRanStatus);
txtRanStatus.setText(strRandomStatus);
You haven't posted any code, so it is difficult to provide something that fits in your scheme of things. But I think this should get you started. You will, possibly, need to adapt a few things and fit them in your own code.
Hope this helps.
EDIT: As per a comment by th OP, adding some bits of code to fetch Facebook Status Messages:
in your onCreate() method:
Start a new AsyncTask:
new getFacebookFeeds().execute();
I use this method in my app to make the Facebook Call to get all feeds from the Graph API.
private class getFacebookFeeds extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... params) {
String URL = "https://graph.facebook.com/me/home&access_token=ACCESS_TOKEN?limit=10";
try {
HttpClient hc = new DefaultHttpClient();
HttpGet get = new HttpGet(URL);
HttpResponse rp = hc.execute(get);
if (rp.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
String result = EntityUtils.toString(rp.getEntity());
// GET THE INTIAL RESULTS JSON ROOT
JSONObject JORoot = new JSONObject(result);
// GET THE "DATA" TAG FOR FEEDS ROOT
JSONArray JAFeeds = JORoot.getJSONArray("data");
for (int i = 0; i < JAFeeds.length(); i++) {
JSONObject JOFeeds = JAFeeds.getJSONObject(i);
if (JOFeeds.has("message")) {
String strStatusMessage = JOFeeds.getString("message");
arrStatusMessage.add(strStatusMessage );
}
}
}
} catch (Exception e) {
// TODO: handle exception
}
}
}
You can do the remaining code, where you select a random Status Update, in the onPostExecute() of the AsyncTask shown above:
#Override
protected void onPostExecute(Void result) {
int intRandom = randomGenerator.nextInt(arrStatusMessage.size());
String strRandomStatus = arrStatusMessage.get(intRandom);
txtRanStatus.setText(strRandomStatus);
}
Declare the TextView as a Global Variable and cast it on your onCreate() before calling the AsyncTask. I think this should work just fine. Let me know how it goes. :-)

android application hangs when it connects to webservice using 3g connection and works fine with WIFI

I am developing an android application that consumes web service , the service output is XML
I am connecting to the web service using this code
public String converse(String host, int port, String path)
throws IOException, URISyntaxException {
BufferedReader in = null;
String serviceResponse = null ;
try {
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet();
String serviceUrl = "http://"+host+":"+port+path;
System.out.println("service url "+serviceUrl);
request.setURI(new URI(serviceUrl));
System.out.println("Request "+request.toString());
HttpResponse response = client.execute(request);
in = new BufferedReader
(new InputStreamReader(response.getEntity().getContent()));
StringBuffer sb = new StringBuffer("");
String line = "";
String NL = System.getProperty("line.separator");
while ((line = in.readLine()) != null) {
sb.append(line + NL);
}
in.close();
serviceResponse = sb.toString();
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return serviceResponse;
}
when the application launches with WI-FI every thing works fine and when I restart the application with 3G connection it hangs and displays a the following dialog
In addition to this code I am using this method inside another method
public void fillAdapter() {
//calling web service using the mentioned method
}
And this function used inside an async task to fill ListView adapter
protected class AsyncLoading extends AsyncTask<Void,Void, BaseModel[]>{
#Override
protected void onPreExecute(){
pd =ProgressDialog.show(BaseListActivity.this, "loading in progress", "waiting .");
}
#Override
protected BaseModel[] doInBackground(Void... params) {
fillAdapter();
return listItems;
}
#Override
protected void onPostExecute(BaseModel[] doc){
//list.setAdapter(doc);
if(doc != null) {
if(doc.length > 0 ) {
if(doc[0] instanceof Activity)
adapter = new OffersListAdapter(getApplicationContext(),doc);
else if (doc[0] instanceof Offer)
adapter = new OffersListAdapter(getApplicationContext(),doc);
else if (doc[0] instanceof Branch) {
adapter = new BranchListAdapter(getApplicationContext(),doc);
Log.i("Branch"," Added Branch");
}else if (doc[0] instanceof Consolation) {
adapter = new ListAdapter(getApplicationContext(),doc);
adapter.setDisplayImage(false);
}else if ( doc[0] instanceof Event) {
adapter = new EventListAdapter(getApplicationContext(),doc);
}
else
adapter = new ListAdapter(getApplicationContext(),doc);
}//end if doc != null
list.setAdapter(adapter);
}
handler.sendEmptyMessage(0);
}
I saw this post but I don't have a good result I'm working on this problem for 2 days
with my thanks in advance .
Note : this problem often appears the first time the application connects to the service after that if I pressed wait and the application continued then al other activities consuming the web service will work fine

I think you have low speed connection of 3G compared to Wi-Fi.So Use Asynctask to load data from server in seperate thread rather than main thread.It is good idea to show ProgressDialog while fetching the data.
And In some cases Apis will work in Wi-Fi and may not in 3G connection.So test Your url in Device browser also to make it confirm

You should use an AsyncTask for every task that could take some time to be executed. See http://developer.android.com/reference/android/os/AsyncTask.html

The problem i am seeing with your code is you are not doing network operation in Thread.
So if you perform asynchronous operation on Main thread,application will display above dialog if it don't receive response in 5 seconds.In your case 3g connection may be taking more than 5 seconds to return response.
Best bet is include above code in Thread!!

I have solved the problem , that I have a splash screen activity inside which I use C2DM and register the device in that activity using service
registrationIntent.putExtra("app", PendingIntent.getBroadcast(getApplicationContext(), 0, new Intent(), 0));
registrationIntent.putExtra("sender", "someemailaddress#gmail.com");
startService(registrationIntent);
I put this code inside an asyncTask and didn't block the UI
Thanks for every one who tried to help me