Backendless - should i subscribe to a channel from service? - java

In Backendless, there is a method from which I can subscribe to a channel and listen for incoming messages.
Backendless.Messaging.subscribe(
channelName, //some random name
500, //500 ms interval for polling
new AsyncCallback<List<com.backendless.messaging.Message>>() {
#Override
public void handleResponse(List<com.backendless.messaging.Message> messages) {
System.out.println("message received on your channel");
}
#Override
public void handleFault(BackendlessFault backendlessFault) {
}
},
new AsyncCallback<Subscription>() {
#Override
public void handleResponse(Subscription subscription) {
System.out.println("You subscribed to channel" + subscription.getChannelName() + " succssesfuly");
}
#Override
public void handleFault(BackendlessFault backendlessFault) {
System.out.println("Error: " + backendlessFault.getMessage());
}
}
);
If it subscribes from the MainActivity, and data was sent while the app is in another Activity, how can it grab the data from the response (the List in the first handleResponse method) and use it in other activities?
Should I use a service? Should I bind activities to this service with the listener?
Or is there any less complicated way to accomplish my need?
In the very near future i want this listener to work when the app is in the background and show a notification to a user.

Backendless uses two types of Messaging, see Publish-Subscribe Messaging & Push Notifications. The first one is implemented using the listener you used above. The second one uses a service. please refer to the docs, although they are not very good at all they do provide the necessary information.

Related

How to manage push notification for chat app using FCM

I'm building a chat app that pushes notification like facebook, Instagram.
when a user sends message notification will show automatically. The problem is I don't know how to handle background service.
For example, when the same user sends the message, a notification will append the message like this:
But when FCM send notification this is what happened:
I need to be able to handle background service
Here is my code
public class FirebaseInstaceService extends FirebaseMessagingService {
FirebaseToken firebaseToken = new FirebaseToken();
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
#Override
public void onNewToken(String s) {
super.onNewToken(s);
Log.d("NewToken","New token: " +s);
if (user != null){
firebaseToken.sendToken(s, new OncompleteCallback() {
#Override
public void callback() {
Log.d("NewToken","Send complete");
}
});
}
}
#Override
public void onMessageReceived(RemoteMessage remoteMessage) {
super.onMessageReceived(remoteMessage);
try {
Log.d("CloudMessage",remoteMessage.getNotification().getBody());
}catch (Exception e){
Log.d("CloudMessage",e.toString());
throw e;
}
}
}
If I understand your question correctly, you need to do work on the non UI thread when a push notification is received. In that case, you're in luck - as explained here, onReceive() is called on a non-UI thread.
You just create and show Notifications as you see fit, storing the notification ID uniquely to allow user->notification mapping. That way, you can access the notification shown when the same user sends another message.

Android - Retrofit web service value problems

I have phone contact numbers list stored in an array and called contactsString[]
and in an online database registered users numbers
I want to count how many registered users are there
and there is my code
for (i=0;i<contactsString.length-1;i++){
Phone phone=new Phone();
phone.phone=contactsString[i]
WebService.getInstance().getApi().checkNumber(phone).enqueue(new Callback<MainResponse>() {
#Override
public void onResponse(Call<MainResponse> call, Response<MainResponse> response) {
if (response.body().status==1){
availableUsers++;
}
}
#Override
public void onFailure(Call<MainResponse> call, Throwable t) {
}
});
}
my problem is the web service response is delayed so it don't count and availableUsers is printed it's initial value which is 0
I would try better sending an array of Phone objects. In this way you would get the correct answer in 1 call.
I would never do this in the way you implemented: imagine you have 500 contacts: you will be doing 500 calls to your server. Now imagine you have 100000 users with 500 contacts each
Try to customize your api call in this format. Which uses async task class.
private void phoneContact() {
new AsyncTask<String,Void,String>() {
#Override
protected String doInBackground(String ... params) {
try {
Platform http = Url_Contacts;
JSONObject resp = http.search(what,where);
Log.d(TAG, "Response: " + resp.toString());
} catch (Exception e) {
Log.e(TAG, e.getMessage());
}
return "";
}
}.execute();
}
Make sure that your service works well and the format of json with value status in there.
In onResponse, run on UIThread to update your View with the availableUsers.
The enqueue method is asynchronous. So your code should respect the multithreaded nature of it.
There are many approaches you can take:
Replace enqueue() method with execute(). But that makes all the calls synchronous. If you call it in UI Thread then whole app can stutter. Probably you will get NetworkOnMainThreadException. Not a good approach anyway.
Use RxAndroid or RxJava with Observer pattern.
Simple solution. Create a variable int callsFinished = 0;. In onResponse increment that variable. Then if that callsFinished == contactsString.length that means all calls have been done.
In your activity add a listener
void onAllCallsFinished(int availableUsers) {
//do what you want with availableUsers information
}
Call onAllCallsFinished(availableUsers) when callsFinished == contactsString.length.
There you can do what you want with that data. Update a view, call another service.

Server-Sent Events using Play 2 Java

I'm trying to implement Server-sent events in the Play 2 framework (version 2.3.9) using Java. I'd like for an event to be sent to the client every time a "Message" entity is saved to the database. The entity should be sent to the client in Json format.
Message message = new Message();
//some code to populate bean here
message.save(); //save to db
//What do I do with message here?
I was thinking of making a service class that will send events.
public class SSEService {
public static void sendEvent(String data, String id, String name){
EventSource eventSource = new EventSource() {
#Override
public void onConnected() {
//no idea what to do here
}
};
EventSource.Event event = new EventSource.Event(data, id, name);
eventSource.send(event);
}
}
I would then call SSEService.sendEvent() after saving the message. Am I on the right track? What does data, id, and name correspond to in the Event constructor?
Can someone provide a good example in Java 7?

Best way to store messages (native + app2app)

I want to develop a messaging app which will show messages from native content provider (sms uri ) and messages that has been sent from my app.
I am stuck while managing this messages.I have tried below idea but plese do suggest which is the best .
Here is the observer code I have used:
public class MyObserver extends ContentObserver {
public MyObserver(Handler handler) {
super(handler);
}
#Override
public void onChange(boolean selfChange) {
Log.e("uri","change");
this.onChange(selfChange, null);
}
#Override
public void onChange(boolean selfChange, Uri uri) {
// do s.th.
// depending on the handler you might be on the UI
// thread, so be cautious!
Log.e("uri",""+uri.toString());
}
}
Uri uri = Uri.parse("content://sms/");
getContentResolver().registerContentObserver(uri,true,new MyObserver(new Handler()));
1.I have saved all native and A2A messages in databases so it was easy to show but I got problem while synching native message gets delete as there is not broadcast listener for message deletion.
2.Second option is two save only a2a message in database but it is complex to and time consuming to get messages from two different places (database and content provider and manage the to show view like inbox)
3.Third is to save all app to app messages in content provider with custom message type.and show all messages from content provider only .
Please guide me on this.

Communicate from Service to Activity via bound service

I've already bound an activity to my service following this tutorial.
http://developer.android.com/guide/components/bound-services.html
I'm able to call service functions, but what if I want to for example, change some of my textviews or disable some of the toggle buttons because of work done on the service (and from the service). Would there be an easy to way to do this?
You can use messages to send information between activities and services. This is an easy way to send simple data, but may not be the best option if you need to send data very frequently, or send complicated data. This is an example of some code I have in one of my apps with a service and an activity which communicate:
Code in the activity:
//this is where you set what you want to happen
class IncomingHandler extends Handler {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
//this switch reads the information in the message (usually just
//an integer) and will do something depending on which integer is sent
case 1: do_something();
case 2: do_something_2(); //etc.
default:
super.handleMessage(msg);
}
}
}
final Messenger myMessenger = new Messenger(new IncomingHandler());
private ServiceConnection mConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className,
IBinder service) {
myService = new Messenger(service);
myCallbackText = (TextView)findViewById(R.id.tv01); //This is a text view which will display status information as needed
myCallbackText.setText("Attached.");
try {
Message msg = Message.obtain(null,
1);
msg.replyTo = mMessenger; //here we send an instance of our messenger implementation as the replyTo address
mService.send(msg);
msg = Message.obtain(null,
3, this.hashCode(), 0);
mService.send(msg); //send a message with the value "3"
} catch (RemoteException e) {
//nothing you can do if the server isn't active
}
Toast.makeText(Service_testActivity.this, R.string.remote_service_connected,
Toast.LENGTH_SHORT).show();//confirmation that the connection happened successfully
}
public void onServiceDisconnected(ComponentName className) {
// This is called when the connection with the service has been
// unexpectedly disconnected -- that is, its process crashed.
mService = null;
mCallbackText = (TextView)findViewById(R.id.tv01);//same textview as before
mCallbackText.setText("Disconnected.");
Toast.makeText(Service_testActivity.this, R.string.remote_service_disconnected,
Toast.LENGTH_SHORT).show();
}
};
Code in the service:
In the service, you will want to have code (very similar to the code in the activity) to receive a message and save the msg.replyTo field as a Messenger object. There is an example somewhere which will have you make an object and then use an IncomingHandler like this:
ArrayList<Messenger> mClients = new ArrayList<Messenger>();
class IncomingHandler extends Handler {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_REGISTER_CLIENT:
mClients.add(msg.replyTo);
break;
case MSG_UNREGISTER_CLIENT:
mClients.remove(msg.replyTo);
break;
default:
super.handleMessage(msg);
}
}
}
This can allow your service to keep track of multiple clients at once and send messages to specified clients. To send a message simply use something like this:
mClients.get(1).send(Message.obtain(null, 3, new Random().nextInt(), 0));
//sends a message to the first client saved in the list

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