OK, here is my code, I'm trying to create a running service even when the app is closed.
In main activity, I have created a new button and call startMyService() to start the service as following:
public void startMyService(View view) {
Intent intent = new Intent(MainActivity.this, MyService.class);
startService(intent);
}
the Service class is simple :
public class MyService extends Service {
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.e("MyService", "service is running");
final Uri uri = Settings.System.DEFAULT_RINGTONE_URI;
final Context x =(Context) MyService.this;
new Thread(new Runnable() {
#Override
public void run() {
MediaPlayer player = MediaPlayer.create(x,uri);
player.setLooping(true);
player.start();
}
}).start();
Toast.makeText(getApplicationContext(), "Service is running", Toast.LENGTH_LONG).show();
return START_STICKY;
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onDestroy() {
super.onDestroy();
Toast.makeText(this, "service done", Toast.LENGTH_SHORT).show();
Log.e("MyService", "service done");
}
}
Of course, I have added the service to manifest
<service android:name=".MyService" android:exported="false" android:description="#string/service_description" />
Now after running, I pressed the button to start the service, and close the activity, I supposed the music will be playing in the background but it stopped just after closing the activity.
How to solve this issue? How to make the service still running, and how to make it running again after an android OS destroying it?
I know there are too many topics about android services and START_STICKY
However, as you see this is not working in code above, why?
Note: This is not about playing music in the background, I used playing music because it is the simplest way to know when service is stopped, this is about how to make service keeps running in the background as supposed to be, for example, to do some task like tracking data changes from the server.
It's normal behavior when your application target from android O, if you want to remain your Service you should use startForgroundService with Notification. Read here
While an app is in the foreground, it can create and run both foreground and background services freely. When an app goes into the background, it has a window of several minutes in which it is still allowed to create and use services. At the end of that window, the app is considered to be idle. At this time, the system stops the app's background services, just as if the app had called the services' Service.stopSelf() methods.
I'm using bound service so that I am able to communicate between an activity and a service.
I'm binding to a service in onStart:
#Override
protected void onStart() {
super.onStart();
Intent bindIntent = new Intent(this, MusicService.class);
bindService(bindIntent, this, BIND_AUTO_CREATE);
}
waiting for service to bind:
#Override
public void onServiceConnected(ComponentName name, IBinder service) {
mMusicService = ((MusicService.LocalBinder) service).getService();
mMusicService.setCallback(this);
}
handling disconnect from service:
#Override
public void onServiceDisconnected(ComponentName name) {
mMusicService = null;
}
unbinding from service in onDestroy:
#Override
protected void onDestroy() {
super.onDestroy();
if (mMusicService != null && isFinishing()) {
mMusicService.setCallback(null);
unbindService(this);
}
}
My problem is that when app is minimized, onDestroy gets called immediately and then onUnbind in Service gets called and music is stopped.
Here is onUnbind method (where mPlayer is MediaPlayer):
#Override
public boolean onUnbind(Intent intent) {
mPlayer.stop();
mPlayer.release();
mPlayer = null;
return super.onUnbind(intent);
}
If I don't implement onUnbind music continues to play (sometimes and sometimes it stops after some time) and when I open the app again (from minimized applications) I am able to play another song and then those two song play at same time.
I've red couple articles about music players and services on android and I thought that this was correct approach (thinking that onDestroy will be called when OS is out of memory).
Any ideas how I can re-implement my app workflow so that I will work as expected?
EDIT
At first I thought that "Don't keep activities" under developer options is a problem, but problem is still there even if I uncheck it.
And if some code from my service is needed please say I will edit my question (there's a lot of code and I'm not sure which part is important for this issue)
SOLUTION:
startForeground(<notification id>, <notification>);
to run service even if app gets killed. And when user dismisses the notification:
stopForeground(true);
stopSelf();
More about startForeground here.
It's not obvious, but you should start a Thread that runs in background and use the service to control it's state.
A service isn't a thread that hold some run state like a thread. Unless it's an IntentService. (Correct me if I'm wrong)
While activity can (and probably will) get destroyed, your app will keep running.
Activity:
#Override
protected void onStart() {
super.onStart();
Intent intent = new Intent(this, BackgroundService.class);
startService(intent);
bindService(intent, mServiceConnection, Context.BIND_AUTO_CREATE);
finishOnPause = true;
}
#Override
protected void onStop() {
super.onStop();
unbindService(mServiceConnection);
}
Service:
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
ensureServiceThread();
if (intent != null) {
}
return START_NOT_STICKY;
}
private void ensureServiceThread() {
if (service_thread == null) {
service_thread = new ServiceThread(this);
service_thread.start();
}
}
#Override
public void onDestroy() {
stopServiceThread();
super.onDestroy();
}
private void stopServiceThread() {
if (service_thread != null) {
service_thread.interrupt();
service_thread = null;
}
}
And you should do your work inside the Thread.
If you need context, it's your Service.
If you need to do something on Main thread - create a Handler in Service.OnCreate and do a handler.postRunnable inside a worker thread safely.
What I would do is:
- Create a service
- Create a thread
- Create a media player inside a thread (if possible, otherwise on Service creation and pass it to thread)
- Inside a thread - continuously poll media player state
- On song finished send an intent to service that change track
- stop thread/service if needed.
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
I have an Android application where I implement a Service which interacts with some hardware over a Bluetooth serial connection. The setup of this connection is slow, so I decided to keep the service in the foreground, so if/when you want to view another application, the connection is ready to go (pseudocode follows):
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
start();
return (START_STICKY);
}
#Override
public void onDestroy() {
stop();
}
start() and stop() are private methods which start communication with the hardware, and in start's case, creates a Notification for use in startForeground() My Activity will call
#Override
public void onStart() {
super.onStart();
// Start the service
Intent intent = new Intent(getApplicationContext(), MyService.class);
ComponentName theService = startService(intent);
//this is to register the functions I need to handle functions my Activity calls
// to the service
bindService(intent, svcConn, BIND_AUTO_CREATE);
}
#Override
public void onStop() {
super.onStop();
if (theService != null) {
unbindService(svcConn);
theService = null;
if (isFinishing()) {
stopService(new Intent(getApplicationContext(), MyService.class));
}
}
}
I've had to add a "Quit" menu item to make sure that the Service shuts down. Worse, if my app crashes, I have to go in and manually kill the Service. Is there a way to elegantly kill the Service if things go horribly wrong, or am I abusing the purpose of a Service, and should find an alternative method of doing what I'd like to do?
Perhaps you can add a hook for your application's main thread(UI thread) for crash, see below:
Runtime.getRuntime().addShutdownHook(new Thread() {
public void run() {
//Kill the service.
}
});
throw new RuntimeException("Uncaught Exception");
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"/>