Everlasting BroadcastReceiver - android

I've a problem with an app I'm coding.
I need to receive ACTION_SCREEN_ON, ACTION_SCREEN_OFF and ACTION_USER_PRESENT intents everytime they're broadcasted, so my app of course stays in background. At the moment my app is made by a settings activity and a service. ScreenReceiver is a BroadcastReceiver that gets the ACTION_SCREEN_* intents, while UnlockReceiver gets the ACTION_USER_PRESENT intent. The service registers and unregisters the receivers:
public class MainService extends Service {
ScreenReceiver screenReceiver = null;
UnlockReceiver unlockReceiver = null;
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onStart(Intent intent, int startId) {
doStart();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
doStart();
return START_STICKY;
}
public void doStart() {
if(screenReceiver != null && unlockReceiver != null)
return;
IntentFilter filter;
if(screenReceiver == null) {
filter = new IntentFilter();
filter.addAction(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
screenReceiver = new ScreenReceiver();
registerReceiver(screenReceiver, filter);
}
if(unlockReceiver == null) {
filter = new IntentFilter();
filter.addAction(Intent.ACTION_USER_PRESENT);
unlockReceiver = new UnlockReceiver();
registerReceiver(unlockReceiver, filter);
}
}
#Override
public void onDestroy() {
if(screenReceiver != null)
unregisterReceiver(screenReceiver);
if(unlockReceiver != null)
unregisterReceiver(unlockReceiver);
}
}
But sometimes Android kills my service to free some RAM and then restarts it. The time between the kill and the respawn is usually around 5 seconds, but sometimes this can be enought to miss some intents causing problems to the users of my app. Those intents can be registered only trought registerReceiver, so I can't register them in the manifest. How could I listen to those intents without being killed or missing some?
Thanks!

How could I listen to those intents without being killed or missing some?
You don't. You rewrite your app to either not use those broadcasts or to be more resilient in the case of missing broadcasts. After all, it is not just "Android kills my service to free some RAM and then restarts it", but task managers and the like that can get rid of your service.

Related

Local broadcast from Service not received by Activity

I have an Activity in which I am registering a BroadcastReceiver locally as follows:
public class SomeActivity extends Activity{
public static final String PERFORM_SOME_ACTION = "PERFORM_SOME_ACTION";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.some_activity_layout);
.....
.....
IntentFilter filter = new IntentFilter();
filter.addAction(PERFORM_SOME_ACTION);
receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// perform some action ...
}
};
registerReceiver(receiver, filter);
}
.....
.....
}
And I have a Service from which I broadcast an Intent as follows:
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Intent i = new Intent(SomeActivity.PERFORM_SOME_ACTION);
sendBroadcast(i); /* Send global broadcast. */
return START_STICKY;
}
This works as intended. After having implemented this, I realized that a local broadcast would be more appropriate for this situation:
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Intent i = new Intent(SomeActivity.PERFORM_SOME_ACTION);
LocalBroadcastManager.getInstance(this).sendBroadcast(i); /* Send local broadcast. */
return START_STICKY;
}
Unfortunately, the above scheme doesn't work. A global broadcast is sent every time, while a local broadcast is apparently never sent/received.
What am I missing here? Can't local broadcasts be sent between two distinct app components, like two separate Activitys or from a Service to an Activity? What am I doing wrong??
Note:
As per the documentation, it is more efficient and more to the point to send a local broadcast (an intra-app broadcast whose scope is restricted to the app's own components) rather than a global broadcast (an inter-app broadcast which is transmitted to every single app on the phone) whenever we do not need the broadcast to propagate outside the application. This is the reason for making the aforementioned change.
What am I missing here?
Use LocalBroadcastManager for registering LocalBroadcast, currently using registerReceiver method of Activity which is used for registering global Broadcast:
LocalBroadcastManager.getInstance(this).registerReceiver(receiver, filter);

Service stops when deploying android app (disapears from settings>>application>>RunningServices)

This is my situation: I have a service running and every time I deploy my app the service disappears from settings>>application>>runningService (therefore, the service is not running) how can I set it so that the service does not disappears?
I have tried to startForeground but it did not worked.
AndroidManifest:
<service
android:name=".service.PhoneCallInOutService"
android:enabled="true"
android:exported="false" >
</service>
This is how I start the service in my Activity:
chkCallsRecord.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
boolean isChecked = chkCallsRecord.isChecked();
updateBackgroundTasks(isChecked);
}
});
The method actually starting the service:
private void updateBackgroundTasks(boolean start) {
Intent serviceIntent = new Intent(getApplicationContext(),PhoneCallInOutService.class);
if (start) {
getApplicationContext().startService(serviceIntent);
} else {
getApplicationContext().stopService(serviceIntent);
}
}
And here is the service:
public class PhoneCallInOutService extends Service {
private TelephonyManager telephonyMgr;
private PhoneCallStateListener pcsListener;
private OutgoingCallReceiver ocReceiver;
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
super.onStartCommand(intent, flags, startId);
// Listener
pcsListener = new PhoneCallStateListener(getApplicationContext(),appDto);
telephonyMgr = (TelephonyManager)getApplicationContext().getSystemService(Context.TELEPHONY_SERVICE);
telephonyMgr.listen(pcsListener, PhoneStateListener.LISTEN_CALL_STATE);
// Receiver
ocReceiver = new OutgoingCallReceiver(getApplication());
IntentFilter intentF = new IntentFilter(Intent.ACTION_NEW_OUTGOING_CALL);
getApplicationContext().registerReceiver(ocReceiver, intentF);
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
// Listener
telephonyMgr.listen(pcsListener, PhoneStateListener.LISTEN_NONE);
// Receiver
getApplicationContext().unregisterReceiver(ocReceiver);
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}
Thank you very much in advance.
If by deploy you mean you try to launch new build of your app, then this is actually normal and expected behaviour. By deploying new build you replace old code (incl. service code) therefore it have to be killed first to avoid any crashes and other oddities. So your old iteration of app is completely killed. Then new app is installed and most often auto-launched. Your data create by the app usually stay, but it's also normal.
EDIT
For security reasons you are not allowed to re-launch itself after being updated. User has to to this. As for "he/she may assume the service is still there running, which is not true", use notification of type "On Going" to indicate running service

Broadcast Receiver in a service but intent not getting caught on service once process is killed

I have a simple widget that does some calculations once the screen comes on and displays them and clears all the fields once the screen goes off ... i have a broadcast receiver setup in my service which listens to ACTION_SCREEN_ON and ACTION_SCREEN_OFF.
This works perfectly as long as the phone doesn't go to sleep for a long period of time or there is heavy usage of the phone - once this happens my widget process is killed (the service is still running but the process is killed) after this when the screen goes off and comes back on my widget doesn't update as the ACTION_SCREEN_ON intent is not caught by my service :(
public class CDTservice extends Service {
#Override
public void onCreate() {
IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
m_receiver = new ScreenBroadcastReceiver();
registerReceiver(m_receiver, filter);
Log.d("Widgettool", "works");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
start();
Toast.makeText(getBaseContext(), "SERVICE ON", Toast.LENGTH_SHORT).show();
return START_REDELIVER_INTENT;
}
#Override
public void onDestroy() {
stop();
unregisterReceiver(m_receiver);
}
public void start()
{
RemoteViews View = new RemoteViews(this.getPackageName(), R.layout.main);
updatewidgetclass x= new updatewidgetclass(this, View, widgetId);
x.start(); // does calculations and displays on widget
}
public void stop()
{
RemoteViews Viewclear = new RemoteViews(this.getPackageName(), R.layout.main);
updatewidgetclass y = new updatewidgetclass(this, Viewclear, widgetId);
y.stop(); // clears resources and stops
}
private class ScreenBroadcastReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
Log.d("ON SCREEN ON", "might hang here");
start();
} else if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
stop();
}
}
}
sometimes when the widget process is not claimed by the android system the widget works perfectly for days and perfectly displays the values ACTION_SCREEN_ON
the problem arises when - i check in settings>apps>running - i can see my widget name and it says 0 processes and 1 service
i assume the broadcast receive is happening on the main process and hence its not receiving it when the process gets killed.
I have a work around in place for this but would really like to fix the issue.
Any helps is highly appreciated
I agree with #CommonsWare that having a service running in the bg at all times just to detect when the screen turns on and off is a very bad idea. Do you really need ACTION_SCREEN_ON, or will ACTION_USER_PRESENT (phone unlocked) suffice? This way, you do not need a service at all, and you can just define the receiver in the manifest.
If you really wanted to, you could register your service/ACTION_SCREEN_OFFreceiver in your ACTION_USER_PRESENT receiver so that the service is only running when the user is actually using the device.
I know this doesn't really answer your question, but it does provide a useful workaround to your problem.

Long running ADK Accessory (Service?)

I've spent days trying to get the android ADK connection running in a service rather then activity..... Anyone know if its even possible?
I would like to have the service handled inputStream and outputStream so I can read my Arduino for extended periods in the background.
When the activity returns to focus I will bind with the service and update the GUI. If this is possible I would eventually like to update a website with the live data from the service for remote monitoring.
Any help if appreciated. I'm new to programming and can't seem to find much info on this topic.
Thank you in advace for the help.
I'm also trying it and I've found out this.
http://robotgrrl.com/blog/2011/11/29/android-adk-background-service/
I was able to get a ADK connection running in the following way (not complete code. Only the basic building blocks):
First I have an activity that the receives adk intent broadcasts (android system service bases on the adk meta data and the manifest).
private static final String USB_ACCESSORY_ATTACHED = "android.hardware.usb.action.USB_ACCESSORY_ATTACHED";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getIntent().getAction() != null && getIntent().getAction().equals(USB_ACCESSORY_ATTACHED)) {
Intent service = new Intent(this, ADKservice.class);
service.putExtras(getIntent());
startService(service);
Intent launch = new Intent(this, MainActivity.class);
launch.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(launch);
}
this.finish();
}
If the intent matches the adk string it will start the adk service and pass the intent information to the service, launch the user interface activity and finish itself.
The user interface (MainActivity) now binds to the service just like any other service so it can call public methods and/or receive data via the service callbacks (local broadcast's can also be used).
The ADKservice extends Runnable to monitor the usb connection. It also registers a receiver for adk disconnect so it can stop if the device gets disconnected:
#Override
public void onCreate() {
IntentFilter filter = new IntentFilter(UsbManager.ACTION_USB_ACCESSORY_DETACHED);
registerReceiver(mUsbReceiver, filter);
mNotificationManager =(NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
mBuilder = new NotificationCompat.Builder(this)
.setSmallIcon(R.drawable.ic_launcher)
.setContentTitle("ADK Service")
.setContentText("Started");
startForeground(notifyID, mBuilder.build());
super.onCreate();
}
After onCreate has finished the service will call onStartCommand where the adk initialization starts.
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.d(TAG, "onStartup " + mAccessory );
mAccessory = (UsbAccessory) intent.getParcelableExtra(UsbManager.EXTRA_ACCESSORY);
if (mAccessory != null) {
openAccessory(mAccessory);
}
return super.onStartCommand(intent, flags, startId);
}
private void openAccessory(UsbAccessory accessory) {
Log.d(TAG, "openAccessory: " + accessory);
UsbManager mUsbManager = (UsbManager) getApplicationContext().getSystemService(Context.USB_SERVICE);
mFileDescriptor = mUsbManager.openAccessory(accessory);
if (mFileDescriptor != null) {
FileDescriptor fd = mFileDescriptor.getFileDescriptor();
mInputStream = new FileInputStream(fd);
mOutputStream = new FileOutputStream(fd);
thread = new Thread(null, this, "ADKserviceThread");
thread.start(); // start runnable
}
public void run() {
// handle adk "usb" messages here
}
#Override
public void onDestroy() {
closeAccessory();
stopForeground(true);
super.onDestroy();
}
private void closeAccessory() {
try {
if (mFileDescriptor != null) {
mFileDescriptor.close();
}
} catch (IOException e) {
} finally {
mFileDescriptor = null;
mAccessory = null;
}
}
private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if(UsbManager.ACTION_USB_ACCESSORY_DETACHED.equals(action)) {
closeAccessory();
stopSelf();
}
}
};
The handling of the connection might need some tweaks but the overall concept seems to work. I hope that helps everyone! It seems easy now but it took me a long time to here (I'm repetitively new to programming)
You should handle the loading of the accessory in the main activity like here, and then pass a reference to the accessory object to a service.
You can now bind the service from any activity and get access to the input/output streams.
You can also close the activity, and when you disconnect the accessory, the activity should catch the intent broadcast and relaunch to perform the closeAccessory routine.

How can we prevent a Service from being killed by OS?

I am using Service in my application and it needs to run until my application is uninstalled, but the problem is it gets killed by OS.
How can we prevent it from being killed by OS? Or if it gets killed can we restart that service again through programmatically?
You may run the service in the foreground using startForeground().
A foreground service is a service that's considered to be something
the user is actively aware of and thus not a candidate for the system
to kill when low on memory.
But bear in mind that a foreground service must provide a notification for the status bar (read here), and that the notification cannot be dismissed unless the service is either stopped or removed from the foreground.
Note: This still does not absolutely guarantee that the service won't be killed under extremely low memory conditions. It only makes it less likely to be killed.
I've been puzzled by the same issue to yours recently.but now,I've found a good solution.
First of all,you should know that, even your service was killed by OS, the onCreate method of your service would be invoked by OS in a short while.So you can do someting with the onCreate method like this:
#Override
public void onCreate() {
Log.d(LOGTAG, "NotificationService.onCreate()...");
//start this service from another class
ServiceManager.startService();
}
#Override
public void onStart(Intent intent, int startId) {
Log.d(LOGTAG, "onStart()...");
//some code of your service starting,such as establish a connection,create a TimerTask or something else
}
the content of "ServiceManager.startService()" is:
public static void startService() {
Log.i(LOGTAG, "ServiceManager.startSerivce()...");
Intent intent = new Intent(NotificationService.class.getName());
context.startService(intent);
}
However, this solution is just available for the situation of your service being killed by GC.Sometimes our service might be killed by user with Programme Manager.In this situation,your prosses will be killed,and your service will never been re-instantiated.So your service can not be restarted.
But the good news is,when the PM kill your service,it will call your onDestroy method.So we can do something with that method.
#Override
public void onDestroy() {
Intent in = new Intent();
in.setAction("YouWillNeverKillMe");
sendBroadcast(in);
Log.d(LOGTAG, "onDestroy()...");
}
The string of "YouWillNeverKillMe" is a custom action.
The most important thing of this method is,don't add any code before send the broadcast.As system will not wait for completion of onDestroy(),you must send out the broadcast as soon as posible.
Then regist a receiver in manifast.xml:
<receiver android:name=".app.ServiceDestroyReceiver" >
<intent-filter>
<action android:name="YouWillNeverKillMe" >
</action>
</intent-filter>
</receiver>
Finally,create a BroadcastReceiver,and start your service in the onReceive method:
#Override
public void onReceive(Context context, Intent intent) {
Log.d(LOGTAG, "ServeiceDestroy onReceive...");
Log.d(LOGTAG, "action:" + intent.getAction());
Log.d(LOGTAG, "ServeiceDestroy auto start service...");
ServiceManager.startService();
}
Hope this will be helpful to you,and excuse my poor written english.
Override method onStartCommand() in your service class and simply return START_STICKY (as suggested by "Its not blank"). That's all you need. If the process that runs your service gets killed (by a low memory condition for example), the Android system will restart it automatically (usually with some delay, like 5 seconds).
Don't use onStart() anymore as suggested in another answer, it's deprecated.
use
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
//**Your code **
// We want this service to continue running until it is explicitly
// stopped, so return sticky.
return START_STICKY;
}
ref Documentation lifecycle of Service.
Edit added method.
As far i know, onDestroy() will be called only when the service is explicitly stopped(Force Stop). But this method won't get called in case the service gets killed by OS/swiping the Recent Apps list. In those cases another event handler named onTaskRemoved(Intent) gets called. This is due to a defect in Android 4.3-4.4 as per the link here. Try using the below code:-
public void onTaskRemoved(Intent intent){
super.onTaskRemoved(intent);
Intent intent=new Intent(this,this.getClass());
startService(intent);
}
I found another solution of the problem which gurantees that your service will be always alive. In my case, this scheme resloves also the problem with FileObserver, which stops work after some period of time.
Use an activity (StartServicesActivity) to start the service (FileObserverService) as Foreground service.
Use BroadcastReceiver class (in example CommonReceiver) to restart your service in some special situations and in case it was killed.
I used this code in my app "Email Pictures Automatically"
https://play.google.com/store/apps/details?id=com.alexpap.EmailPicturesFree
Here is CommonReceiver class.
public class CommonReceiver extends BroadcastReceiver {
public void onReceive(Context paramContext, Intent paramIntent)
{
paramContext.startService(new Intent(paramContext, FileObserverService.class));
}
}
Here is its definition in AndroidManifest.xml just before application closing tag.
<receiver android:name="com.alexpap.services.CommonReceiver">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED"/>
</intent-filter>
<intent-filter>
<action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.USER_PRESENT"/>
</intent-filter>
</receiver>
Start service in StartServicesActivity activity.
Intent iFileObserver = new Intent(StartServicesActivity.this, FileObserverService.class);
StartServicesActivity.this.startService(iFileObserver);
Here is onStartCommand() method of the service.
public int onStartCommand(Intent intent, int flags, int startId) {
int res = super.onStartCommand(intent, flags, startId);
/*** Put your code here ***/
startServiceForeground(intent, flags, startId);
return Service.START_STICKY;
}
public int startServiceForeground(Intent intent, int flags, int startId) {
Intent notificationIntent = new Intent(this, StartServicesActivity.class);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);
Notification notification = new NotificationCompat.Builder(this)
.setContentTitle("File Observer Service")
.setContentIntent(pendingIntent)
.setOngoing(true)
.build();
startForeground(300, notification);
return START_STICKY;
}
I tested this code using Task Killer app, and each time the service was killed, it was restarted again almost immediately (performs onStartCommand()). It is restarted also each time you turn on the phone and after rebooting.
I use this code in my application, which emails every picture you take with your phone to predefinde list of emails. The sending email and list of receiving emails are set in another activity and are stored in Shared Preferences. I took about 100 pictures in several hours and all they were sent properly to receiving emails.
#Override
public void onDestroy() {
super.onDestroy();
startService(new Intent(this, YourService.class));
}
write above code in your service and your service will never stop even user want to destroy it or they want to kill it it will never kill untill your app not get uninstall from your device
You can try to start your service repeatedly, for example every 5 sec.
This way, when your service is running, it will perform onStartCommand() every 5 sec. I tested this scheme and it is very reliable, but unfortunately it increases slightly phone overhead.
Here is the code in your activity where you start the service.
Intent iFileObserver = new Intent(StartServicesActivity.this, FileObserverService.class);
PendingIntent pendingIntentFileObserver = PendingIntent.getService(StartServicesActivity.this, 0, iFileObserver, 0);
AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
Date now = new Date();
//start every 5 seconds
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, now.getTime(), 5*1000, pendingIntentFileObserver);
And here is onStartCommand() of the service.
//class variable
public static boolean isStarted = false;
public int onStartCommand(Intent intent, int flags, int startId) {
int res = super.onStartCommand(intent, flags, startId);
//check if your service is already started
if (isStarted){ //yes - do nothing
return Service.START_STICKY;
} else { //no
isStarted = true;
}
/**** the rest of your code ***/
return Service.START_STICKY;
}
First create service in another process, and write broadcaster which runs in recursion in time intervals
protected CountDownTimer rebootService = new CountDownTimer(9000, 9000) {
#Override
public void onTick(long millisUntilFinished) {
}
#Override
public void onFinish() {
sendBroadcast(reboot);
this.start();
Log.d(TAG, "rebootService sending PREVENT AUTOREBOT broadcast");
}
};
After that register broadcast receiver in main process also with timer recursion that is launched after first broadcast from service arrived
protected static class ServiceAutoRebooter extends BroadcastReceiver {
private static ServiceAutoRebooter instance = null;
private RebootTimer rebootTimer = null;
private static ServiceAutoRebooter getInstance() {
if (instance == null) {
instance = new ServiceAutoRebooter();
}
return instance;
}
public class RebootTimer extends CountDownTimer {
private Context _context;
private Intent _service;
public RebootTimer(long millisInFuture, long countDownInterval) {
super(millisInFuture, countDownInterval);
}
#Override
public void onTick(long millisUntilFinished) {
}
#Override
public void onFinish() {
_context.startService(_service);
this.cancel();
Log.d(TAG, "Service AutoRebooted");
}
}
#Override
public void onReceive(Context context, Intent intent) {
if (rebootTimer == null) {
Log.d(TAG, "rebootTimer == null");
rebootTimer = new RebootTimer(10000, 10000);
rebootTimer._context = context;
Intent service = new Intent(context, SomeService.class);
rebootTimer._service = service;
rebootTimer.start();
} else {
rebootTimer.cancel();
rebootTimer.start();
Log.d(TAG, "rebootTimer is restarted");
}
}
}
Service will be auto-rebooted if time at RebootTimer (main process) expires, which means that "PREVENT AUTOREBOT" broadcast from service hasn't arrived
i found a solution .... late answer but i wanted to answer...
we can send a broadcast in the ondestroy of the service and create a receiver that receives the broadcast and starts the service again.... when it is destroyed by any reasons...
pls try following:
final Messenger mMessenger = new Messenger(new IncomingHandler());
class IncomingHandler extends Handler {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
default:
super.handleMessage(msg);
}
}
}
#Override
public void onCreate() {
super.onCreate();
makeServiceForeground();
}
#Override
public IBinder onBind(Intent arg0) {
return mMessenger.getBinder();
}
private void makeServiceForeground() {
IActivityManager am = ActivityManagerNative.getDefault();
try {
am.setProcessForeground(onBind(null), android.os.Process.myPid(), true);
} catch (RemoteException e) {
Log.e("", "cant set to foreground" + e.toString());
}
}
also need add in manifest.xml
<uses-permission android:name="android.permission.SET_PROCESS_LIMIT"/>

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