Android: Service restarts after app gets started - android

Im trying to achive, that my service downloads information and fills a database with that information in the background.
SOLUTION (Using foreground service, code is now the edited-version)
Thats the service:
public class UnitPullService extends Service {
private final static String name = UnitPullService.class.getSimpleName();
public static Boolean isRunning = false;
private Looper mServiceLooper;
private ServiceHandler mServiceHandler;
private final class ServiceHandler extends Handler {
public ServiceHandler(Looper looper) {
super(looper);
}
#Override
public void handleMessage(Message msg) {
try {
UnitDataSource unitdataSource = new UnitDataSource(getApplicationContext());
unitdataSource.fillTables();
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor spEitor = sharedPreferences.edit();
// disables the button which starts this service
spEitor.putBoolean("isFilled", true);
spEitor.commit();
} catch (JSONException e) {
e.printStackTrace();
}
stopSelf(msg.arg1);
}
}
#Override
public void onCreate() {
HandlerThread thread = new HandlerThread("ServiceStartArguments",
Process.THREAD_PRIORITY_BACKGROUND);
thread.start();
mServiceLooper = thread.getLooper();
mServiceHandler = new ServiceHandler(mServiceLooper);
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// PART OF THE SOLUTION
startForeground(1000, new Notification());
Toast.makeText(this, "service starting",
Toast.LENGTH_SHORT).show();
// to check if the service is currently running
isRunning = true;
Message msg = mServiceHandler.obtainMessage();
msg.arg1 = startId;
mServiceHandler.sendMessage(msg);
return START_REDELIVER_INTENT;
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onDestroy() {
Toast.makeText(this, "service done", Toast.LENGTH_SHORT).show();
}
}
And thats the intent in the activity (actually from a fragment):
Intent i= new Intent(getContext(), UnitPullService.class);
getContext().startService(i);
In the manifest, the service is declared like:
<service
android:name=".UnitPullService"
android:exported="false"/>
The point is, that i want to do the whole "download and database filling"-stuff completly independent from the status of the app which is starting the service (so that the user can use other apps while the service is doing its job).
EDIT (Made false assumptions)
The following behaves weird:
Start application
Start service
Close application (swipe away from running-apps-overview)
Start application before service has finished
"service starting"-toast shows up, handleMessage() gets called and DatabaseErros happening (because of unique constrains, but thats not the point).
the other scenario:
Start application
Start service
Close application (swipe away from running-apps-overview)
fillTables() has finished.
It seems that directly after fillTables() has finished and the service gets restarted (Toast shows up).
Q1: So where is my fault, that the running service is going to restart when I start the application while a running service has not finished yet?
Q1.1: How do i call/create a completly independent service, which does not get restarted in such an anoying way, while doing its job?

Swiping away the app puts it in Force-close state. That kills any services attached to it. It won't allow the service or any other activity in the app to run again until the user has launched it.
Now if the user doesn't swipe away, your service will continue to run no matter what app is in the foreground. And if the service is killed by the OS for resources, you can have it automatically restart when they're available. But nothing will make it run services after being swiped away.

Related

Background Service not working on 7+ android version

I want to show local notification in an Android app that i am working. notification are based on network transaction completed in background.
I have tried service, intent service, jobservice etc but nothing is working when the app is closed.please share some working code for the reference.....
//Here is my service----
public class JobSyncFAQ extends Service {
private Message msg;
private Looper mServiceLooper;
private ServiceHandler mServiceHandler;
public JobSyncFAQ() {
}
private final class ServiceHandler extends Handler {
public ServiceHandler(Looper looper) {
super(looper);
}
#Override
public void handleMessage(Message msg) {
// here is my stuff
stopSelf(msg.arg1);
}
}
public void onCreate() {
super.onCreate();
HandlerThread thread = new HandlerThread("JobSyncFAQ", Process.THREAD_PRIORITY_BACKGROUND);
thread.start();
mServiceLooper = thread.getLooper();
mServiceHandler = new ServiceHandler(mServiceLooper);
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
msg = mServiceHandler.obtainMessage();
msg.arg1 = startId;
mServiceHandler.sendMessage(msg);
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
mServiceHandler.removeCallbacks(mServiceLooper.getThread());
mServiceLooper.quit();
Intent intent = new Intent(getApplicationContext(),JobSyncFAQ.class);
sendBroadcast(intent);
}
//and in my receiver
public void onReceive(Context context, Intent intent) {
context.startService(new Intent(context, JobSyncFAQ.class));
}
please note - i am facing this issue only for N+ version
When you "close" your app (i. e. you swipe it away on the recent apps screen), you don't actually close the app, you only close the underlying activity. In most cases, this corresponds to the app being closed, but if you have a background service running, the service is not terminated. This is for a good reason: YOu still want to receive WhatsApp messages, even when WhatsApp is closed. Hence, WhatsApp starts a background service to check for new messages, even when the app is closed.
For that reason, you need to notify your background service about the fact that it should cancel its task.
I developed a media application that uses a MediaBrowserService which is connected to a MediaController. Therefore, I can do the following in my activities onDestroyMethod:
MediaControllerCompat mediaControllerCompat = MediaControllerCompat.getMediaController(getActivity());
if (mediaControllerCompat != null)
mediaControllerCompat.getTransportControls().stop();
This tells the MediaBrowserService to stop and quit.
Edit: Since you use a generic service, you need to call stopService:
stopService(new Intent(MyActivity.this, JobSyncFAQ.class));

background service for Notification is not working

I tried to use the following code trigger toast as background service but it gets executed for 20 times, it was not working till 100. With thread it is not working gives error.
Felt service get destroyed.
How to trigger notification with 30 minutes difference as a background service, though app is closed,
I need to display Good morning, Good Afternoon, Good Evening and Good night as a Notification.
without any internet support.
Is following procedure not ok? I think so. How to do this?
import android.app.Service;
public class HelloService extends Service {
private static final String TAG = "HelloService";
int i=0;
private boolean isRunning = false;
#Override
public void onCreate() {
Log.i(TAG, "Service onCreate");
Toast.makeText(this, " On create Hello Service Started", Toast.LENGTH_LONG).show();
isRunning = true;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i(TAG, "Service onStartCommand");
for (;i<100; i++) {
try {
// Thread.sleep(1000);
Toast.makeText(getApplicationContext(), "Hello Service On Loop"+i , Toast.LENGTH_LONG).show();
//
} catch (Exception e) {
}
}
//Stop service once it finishes its task
// i++;
stopSelf();
return Service.START_STICKY;
}
#Override
public IBinder onBind(Intent arg0) {
Log.i(TAG, "Service onBind");
return null;
}
#Override
public void onDestroy() {
isRunning = false;
Log.i(TAG, "Service onDestroy");
}
}
onStartCommand() is called on the main (UI) thread. If you execute a loop inside onStartCommand(), Android will kill the process after about 30 seconds with an ANR (Application Not Responding) because you cannot block the main (UI) thread.
You can do what you want either using AlarmManager to set a timer that will start your Service or trigger a BroadcastReceiver at certain times, or you can post a Runnable to a Handler in onStartCommand() with a certain delay and do whatever you want in the Runnable, or you can start a background thread in onStartCommand() and the background thread can loop and sleep or whatever and then do what you want.
In any case, you cannot show a Toast every second. This will flood the UI with toasts and either Android will dump most of them (ignore them) or the UI will be so busy showing them that Android will kill your app due to ANR or the user will just uninstall your app!

Checking for new data in background

What is the recommended approach for checking for new data regardless if the app is in the foreground or background? I am wondering which Android API people are typically using to do this. There seems to be a few ways to achieve my goal, and I want to make sure I'm on the right path.
I have something put together which uses AlarmManager.SetInexactRepeating() to call an IntentService which does the sync and inserts/updates data in the database. This works while the app is in the foreground and background, but if I force stop the app then I keep seeing "Unfortunately, has stopped working" messages when the AlarmManager alarm would've triggered. In this case, I only care about checking for new data only when the app is running in the foreground or background.
My first thought is to detect when the app is force closed, and stop the alarm, but that does not seem possible. So I am asking here, is my approach wrong? If so, which approach is used to perform some periodic task regardless if the phone is in the foreground or background? The problem with the AlarmManager solution I am using is the alarms continue to fire even when the app is closed.
If your idea is to check if your API has new data and perform a background sync to your local database or other data storage, I think you would like to take a look at this:
Creating a Sync Adapter
Running a Sync Adapter
The Sync adapter is the recommended way of achieving this in Android. The pros of using it are multiple:
Optimisations out of the box - the OS bundles calls, uses the most appropriate windows to run the sync adapter at a minimal bandwidth and battery cost
The lifecycle of your background sync component is managed internally by the OS
Observers can be notified when data has been changed so the UI can be updated easily
Multiple ways of running the sync - at intervals, automatically with the OS message to keep TCP/IP connections open or on demand
However, implementing this requires some things, that can cause a bit of a pain at first:
It is mandatory that the adapter works with a ContentProvider
Sync Adapters use Account for authentication. If this is not needed, a Stub has to be provided
For backgrounding on Android usually you use even a Service that can run alone and independently from the App or a Bounded service that takes and returns data from the App. A complete reference on backgrounding can be found here
Using a Service is the right way to go. Have your app start the Service and it will continue running while the app is in the foreground or the background. Then, if you want to kill the Service when your app closes, you could just call stopService(yourServiceIntent); from the onDestroy() override in your app's activity. That should effectively shut down the service when the app closes.
So some sample code of how this works (taken from the Services docs)...
The Service (just Logs a message every 1 second for 60 seconds):
public class MyService extends Service {
private Looper mServiceLooper;
private ServiceHandler mServiceHandler;
// Handler that receives messages from the thread
private final class ServiceHandler extends Handler {
public ServiceHandler(Looper looper) {
super(looper);
}
#Override
public void handleMessage(Message msg) {
long endTime = System.currentTimeMillis() + 60*1000;
while (System.currentTimeMillis() < endTime) {
synchronized (this) {
try {
wait(1000);
Log.d("SERVICE", "The service is still running.");
} catch (Exception e) {
e.printStackTrace();
}
}
}
stopSelf(msg.arg1);
}
}
#Override
public void onCreate() {
HandlerThread thread = new HandlerThread("ServiceStartArguments", Process.THREAD_PRIORITY_BACKGROUND);
thread.start();
mServiceLooper = thread.getLooper();
mServiceHandler = new ServiceHandler(mServiceLooper);
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Message msg = mServiceHandler.obtainMessage();
msg.arg1 = startId;
mServiceHandler.sendMessage(msg);
return START_NOT_STICKY;
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onDestroy() {
}
}
And in your activity you would do something like:
public class MainActivity extends AppCompatActivity {
Intent serviceIntent;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
serviceIntent = new Intent(this, MyService.class);
startService(serviceIntent);
}
#Override
protected void onDestroy() {
stopService(serviceIntent);
super.onDestroy();
}

Stop the Service after the Vibrating the Phone in android?

I am trying to learn service in android.My goal is like that i will pass a LatLng Object to the service then service will do something with that and when the work will be finished then it will buzz the phone for sometime and stop.Finally the service will be finished.Now I have some query on that:
I will call the service from my app and user can close my app though
service is not finished.will service do the job initiated by my app or
it will also finish??
What i studied take me here that service will continue to execute and one thing i don't have to return anything back to activity who has initiated the service.I have written some code.Can anyone help me out??
public class MapService extends Service {
private boolean isRunning = false;
#Override
public void onCreate() {
Log.i(TAG, "Service onCreate");
isRunning = true;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i(TAG, "Service onStartCommand");
//Creating new thread for my service
//Always write your long running tasks in a separate thread, to avoid ANR
new Thread(new Runnable() {
#Override
public void run() {
//here i will do my work
if(isRunning){
Log.i(TAG, "Service running");
}
}
//Stop service once it finishes its task
stopSelf();
}
}).start();
return Service.START_STICKY;
}
#Override
public IBinder onBind(Intent arg0) {
Log.i(TAG, "Service onBind");
return null;
}
#Override
public void onDestroy() {
isRunning = false;
Log.i(TAG, "Service onDestroy");
}
}
Will it work if user closes the app??
Yes this service will run even if user will close app.It is also possible if android system demands memory service will be stopped but it will restart again
as you have set your flag START_STICKY in your onStartCommand.
On Android KitKat and above(4.4+), the service will be stopped if user swipe kills the application and it won't be restarted by the system. See this discussion(1). If the application was stopped by Android system itself (for low resources), the service will be restarted after a while(use START_STICKY flag).
On Android 4.3 and below, service will be restarted irrespective of whether application was stopped by system or user(use START_STICKY flag).
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// We want this service to continue running until it is explicitly stopped, so return sticky.
return START_STICKY;
}

Android: Developing apps that run in the 'background', how?

I am used to developing standalone applications, ones that you click on, it runs, and when you are done, you exit.
I am now interested in tackling a new type (not sure if that's the right word) of app, and was wondering how I should go about it. I am not sure what to research, and would appreciate your advice to help me get the ball rolling. I'll give you an idea about what I have in mind.
My app would need to perform a special action in the dialer. When the user dials a number and is in the middle of a call, I would like the user to be able to press the Menu key, and find an option to scroll through all their contacts (either the stock app, or my own list which I grab from the contacts stored in the phone), and select one. Upon selection, that contact's number is pasted into the dialer (keep in mind, in the middle of a call).
I certainly don't expect an answer telling me how to do this exactly, I just need some guidance as I have never written an app of this nature before. On top of that, is it even possible to do what I want to do?
Thank you.
You need to go through Android Service or IntentService. A Service is an application component that can perform long-running operations in the background and does not provide a user interface(UI).
The following example is taken from android blog which is an implementation of the Service class
public class HelloService extends Service {
private Looper mServiceLooper;
private ServiceHandler mServiceHandler;
// Handler that receives messages from the thread
private final class ServiceHandler extends Handler {
public ServiceHandler(Looper looper) {
super(looper);
}
#Override
public void handleMessage(Message msg) {
// Normally we would do some work here, like download a file.
// For our sample, we just sleep for 5 seconds.
long endTime = System.currentTimeMillis() + 5*1000;
while (System.currentTimeMillis() < endTime) {
synchronized (this) {
try {
wait(endTime - System.currentTimeMillis());
} catch (Exception e) {
}
}
}
// Stop the service using the startId, so that we don't stop
// the service in the middle of handling another job
stopSelf(msg.arg1);
}
}
#Override
public void onCreate() {
// Start up the thread running the service. Note that we create a
// separate thread because the service normally runs in the process's
// main thread, which we don't want to block. We also make it
// background priority so CPU-intensive work will not disrupt our UI.
HandlerThread thread = new HandlerThread("ServiceStartArguments",
Process.THREAD_PRIORITY_BACKGROUND);
thread.start();
// Get the HandlerThread's Looper and use it for our Handler
mServiceLooper = thread.getLooper();
mServiceHandler = new ServiceHandler(mServiceLooper);
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Toast.makeText(this, "service starting", Toast.LENGTH_SHORT).show();
// For each start request, send a message to start a job and deliver the
// start ID so we know which request we're stopping when we finish the job
Message msg = mServiceHandler.obtainMessage();
msg.arg1 = startId;
mServiceHandler.sendMessage(msg);
// If we get killed, after returning from here, restart
return START_STICKY;
}
#Override
public IBinder onBind(Intent intent) {
// We don't provide binding, so return null
return null;
}
#Override
public void onDestroy() {
Toast.makeText(this, "service done", Toast.LENGTH_SHORT).show();
}
}
On the other hand, The same thing can be achieved using IntentService, which is a base class for Services that handle asynchronous requests on demand.
public class HelloIntentService extends IntentService {
/**
* A constructor is required, and must call the super IntentService(String)
* constructor with a name for the worker thread.
*/
public HelloIntentService() {
super("HelloIntentService");
}
/**
* The IntentService calls this method from the default worker thread with
* the intent that started the service. When this method returns, IntentService
* stops the service, as appropriate.
*/
#Override
protected void onHandleIntent(Intent intent) {
// Normally we would do some work here, like download a file.
// For our sample, we just sleep for 5 seconds.
long endTime = System.currentTimeMillis() + 5*1000;
while (System.currentTimeMillis() < endTime) {
synchronized (this) {
try {
wait(endTime - System.currentTimeMillis());
} catch (Exception e) {
}
}
}
}
}
You can also go through SO post https://stackoverflow.com/a/4353653/432903
If your app isn't mainly written in javascript/webview/phonegap, then all you have to do is look at the Service class. That class and the linked documents tell you everything you need to know.
maybe you can use an IntentFilter so you can get a system notify when the user uses a dialer.
and you should learn the Service component which can work in background in android.

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