Develop Reference

Receiving data in activity from a service

I've look at many solutions to other questions with similar issues but I can't figure out what's wrong with my code. I understand that LocalBroadcast is a popular way to do this and I've spent time trying to implement it. At the moment, the receiver isn't declared in my manifest but from what I understand, that's what the register lines are for.
In my activity:
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Log.d("MyActivity", "onReceive");
String action = intent.getAction();
int current = intent.getIntExtra("test", 0);
Toast.makeText(MyActivity.this, current.toString(), Toast.LENGTH_LONG).show();
}
};
#Override
public void onResume() {
super.onResume();
Log.d("MyActivity", "onResume()");
LocalBroadcastManager.getInstance(MyActivity.this).registerReceiver(
mMessageReceiver, new IntentFilter("currentUpdate"));
}
#Override
protected void onPause() {
Log.d("MyActivity", "onPause()");
LocalBroadcastManager.getInstance(MyActivity.this).unregisterReceiver(mMessageReceiver);
super.onPause();
}
In the service I have a method defined:
private void sendNewBroadcast(Intent intent, int current){
intent.putExtra("test", current);
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
Log.d("MyService", "new Broadcast sent from service");
}
and I use it like this elsewhere in the service:
Intent intent = new Intent("currentUpdate");
sendNewBroadcast(intent, 5);
I've debugged and everything seems to be working except for the 'receiving' part. Am I missing something? The service is started in a different activity and is ongoing.

Firstly, the action String on the broadcast Intent needs to match the action set on the IntentFilter you're registering the Receiver with. Originally, they were different, but it was possibly just a typo.
Secondly, LocalBroadcastManager does not work across processes. The Activity and the Service must be running in the same process to be able to use LocalBroadcastManager. If the Service needs to be in a separate process, you'll have to use some other mechanism; e.g., Intents, broadcasts sent and received on a Context, some event bus implementation that supports IPC, etc.

How to call IntentService from WakefulBroadcastReceiver

I have an IntentService defined as below:
<service android:name=".service.AppService" android:process=":app_process" android:icon="#mipmap/ic_launcher" />
I have a WakefulBroadcastReceiver that receives some data and I would like to call my already running service above. The service above is always running, even if it is killed, it restarts. How can I pass messages to that?
I read the following:
http://www.mysamplecode.com/2011/10/android-intentservice-example-using.html
http://www.truiton.com/2014/09/android-service-broadcastreceiver-example/
http://developer.android.com/guide/components/services.html
I tried to do a startService, PendingIntent among other things and nothing seems to work.

First of all, remember that an IntentService works in a different worker thread, there for it's not possible to have intercommunication with the Activity that invoked it. That's why mostly we use them for synchronization on background where feedback to the user is not needed. However, if you want to pass some information to the Activity, you have to use a BroadcastReceiver as you said, and from there create the Intent that will send "data" to the Activity.
Going back to your question, you have to add the service and the receiver in your AndroidManifest.xml inside the <application> tag
<service android:name=".AppService"
android:enabled="true"/>
<receiver android:name=".WakefulBroadcastReceiver" >
</receiver>
Then in your Activity launch the service like this (whenever you need it, in the onCreate, or in a button listener)
IntentFilter filter = new IntentFilter(WakefulBroadcastReceiver.ACTION_RESP);
filter.addCategory(Intent.CATEGORY_DEFAULT);
WakefulBroadcastReceiver broadcastReceiver = new WakefulBroadcastReceiver();
registerReceiver(broadcastReceiver, filter);
In your BroadcastReceiver you override the onReceive() method like this:
#Override
public void onReceive(Context context, Intent intent) {
// HERE IS WHERE YOU RECEIVE THE INFORMATION FROM THE INTENTSERVICE, FROM HERE YOU CAN START AN ACTIVITY OR WHATEVER YOU AIM
Toast.makeText(context, "IntentService Broadcasting", Toast.LENGTH_SHORT).show();
}
Also in the same BroadcastReceiver add this variable that identifies the intentfilter:
public static final String ACTION_RESP = "MY_FILTER_NAME"
In your IntentService class you have to override the onHandleIntent() method like this:
#Override
protected void onHandleIntent(Intent intent) {
String msg = intent.getStringExtra("MSG");
Intent broadcast = new Intent();
broadcast.setAction(WakefulBroadcastReceiver.ACTION_RESP);
broadcast.addCategory(Intent.CATEGORY_DEFAULT);
broadcast.putExtra("MSG", resultTxt);
// HERE IS WHERE YOU SEND THE INFORMATION YOU LOADED TO THE APP
sendBroadcast(broadcast);
}
I have a demo project in my GitHub account here, where I use bound and unbound services and IntentServices:
https://github.com/isaacurbina/PermissionsAndServices
I hope it helps.
Kind regards!

You can write this in your class that extends WakefulBroadcastReceiver :
#Override
public void onReceive(Context context, Intent intent) {
Intent gcmIntent = new Intent(context, MessageService.class);
gcmIntent.putExtras(intent.getExtras());
startWakefulService(context, gcmIntent);
setResultCode(Activity.RESULT_OK);
}
And write this in your class that extend IntentService :
#Override
protected void onHandleIntent(Intent intent) {
Bundle bundle = intent.getExtras();
//do sth with that data
MessageReceiver.completeWakefulIntent(intent);
}

Stop IntentService from inside my application?

I'm building some kind of chat program that uses GCM to notify the user that a message is available. I followed the gcm client example using a WakefulBroadcastReceiver and IntentService and everything works as expected.
The BroadcastReceiver:
public class GcmBroadcastReceiver extends WakefulBroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
// Explicitly specify that GcmIntentService will handle the intent.
ComponentName comp = new ComponentName(context.getPackageName(), GcmIntentService.class.getName());
// Start the service, keeping the device awake while it is launching.
startWakefulService(context, (intent.setComponent(comp)));
setResultCode(Activity.RESULT_OK);
}
}
and the IntentService:
public class GcmIntentService extends IntentService {
public static final int NOTIFICATION_ID = 1;
private NotificationManager mNotificationManager;
public GcmIntentService() {
super("GcmIntentService");
}
public static final String TAG = "IOAN";
#Override
protected void onHandleIntent(Intent intent) {
Bundle extras = intent.getExtras();
GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
// The getMessageType() intent parameter must be the intent you received
// in your BroadcastReceiver.
String messageType = gcm.getMessageType(intent);
if (!extras.isEmpty()) { // has effect of unparcelling Bundle
if (GoogleCloudMessaging.MESSAGE_TYPE_MESSAGE.equals(messageType)) {
// Post notification of received message.
sendNotification(extras.getString("sender"), extras.getString("message"));
Log.i(TAG, "Received: " + extras.toString());
}
}
// Release the wake lock provided by the WakefulBroadcastReceiver.
GcmBroadcastReceiver.completeWakefulIntent(intent);
}
//... more stuff
}
So the IntentService sends a notification to my application.
Now, when the user closes my application (back button -> are you sure you want to exit? -> yes), I want to also have a check box "do you still want to receive messages?" (or something like that), and if the user chooses not to receive messages, I want to stop the service that handles the gcm message and restart it when the app runs again.
How do I do that?
Edit: I tried stopService(new Intent(MainActivity.this,GcmIntentService.class)); but I still get the notifications.
Edit 2: Seems like a boolean value in SharedPreferences works fine... any better solution?

Service not handling Intent when called from Receiver

Rarely I have an issue where a phone will get in a state (known as "funny state") where my Intent Services won't get a startService command from a Broadcast Receiver. (yes, the manifest has the receivers and services defined).
In this example I am listening for push notifications then calling a CheckinService.
Receiver:
public class PushReceiver extends BroadcastReceiver {
private static final String LOG_TAG = "push_receiver";
#Override
public void onReceive(Context context, Intent intent) {
logger.putExtra("debug", "Received Push");
Intent serviceIntent = new Intent(context, CheckinService.class);
context.startService(serviceIntent);
logger.putExtra("debug", "Sent to Service");
}
Service:
public class CheckinService extends IntentService {
private static final String LOG_TAG = "checkin_service";
public static final int SERVICE_ID = 3;
public CheckinService() {
super(LOG_TAG);
Log.i(LOG_TAG, "Service says: Checkin service started no constructor");
}
public CheckinService(String name) {
super(LOG_TAG);
Log.i(LOG_TAG, "Service says: Checkin service started with constructor");
}
#Override
protected void onHandleIntent(Intent intent) {
Log.i(LOG_TAG, "Auto Checkin started");
.....tons of genius logic.....
}
}
So when the phone gets in the funny state the "received push" gets logged and the "sent to service" gets logged but the constructors and onHandleIntent methods of the service never get called.
I also have this happen not only on pushes but on receivers for inexactRepeatingAlarm and perhaps others but these two have been confirmed for sure.
Again this is very, very, rare and seems to happen after the phone has been left unused for a period of time; and perhaps goes into a power saving mode.
Also, terminating the application's process clears this up.

I realized what was happening here.
The IntentService is single threaded. So if something in my " .....tons of genius logic....." was blocking (like a http request with no timeout) the next intent that came into the service would not be processed.
Nice and humbling.

service displays points on map android

i have a android service running in the background which receives the coordinates from the server every few seconds. i am not sure how do i display the coordinates on a map every time the service receives a response from the server. kindly help or give an idea.
thanks

I don't know any tutorials on this, but here's a version of mine:
To send a broadcast, you use the 'sendBroadcast(Intent i)' method of the Context class. The Service class extends Context, so you can access it from your implementation.
So in your Service goes:
public static final String BROADCAST_ACTION="com.yourservice.update";
public void onStart( Intent intent, int startId ) {
...
Intent broadcastIntent = new Intent(BROADCAST_ACTION);
sendBroadcast(broadcastIntent);
...
}
You have to register a receiver for this broadcast in you Activity (possibly before you start boradcasting them), like this:
private BroadcastReceiver receiver=new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
//Here goes handling the stuff you got from the service
Bundle extras = intent.getExtras();
if(extras != null)processUIUpdate(extras);
}
};
public void onResume() {
...
//Register for the update broadcasts from the torrent service
registerReceiver(receiver, new IntentFilter(YourService.BROADCAST_ACTION));
...
}
Don't forget to deregister when the Activity goes background:
public void onPause() {
...
//Deregister for the update broadcast from the torrent service
unregisterReceiver(receiver);
...
}
This should work.

Your service could broadcast intents whenever it wants to update the displayed location on the map. The Activity displaying the map should register a receiver for that boradcast, and the boradcast's intent can hold the values for lat. and long.