There are a class of Android applications that enable password protection on certain user-specified apps; for example, Android Protector. I need to approach this problem from a different direction.
Is it possible to create an application that blocks all activity launches unless they are on a predefined whitelist? Will there be unintended consequences with this approach? I am familiar with Android basics and have written a few reasonably simple apps, but I'm still trying to figure out how these "Protector" apps intercept the launch intents correctly. Would someone mind giving me a brief overview on the correct way to do this?
The basic problem is that we have a generic Android phone that needs to be locked down so that our clients (internal only) can access our custom applications without being able to play "Need for Speed", etc. I would like to remove the carrier bloatware, but rooting the device seems like it would be a maintenance headache. We want the setup for each phone to be as simple as installing a few custom applications.
Edited to elaborate on the solution
Overview
My simple solution was to add a new service and activity to my application. The service uses Handler and postDelayed to continuously schedule the monitoring task. The monitoring task checks that the current activity is on the whitelist. Getting the currently running activity involves ActivityManager and a call to getRunningTasks. After finishing the check, the monitoring task schedules itself to run again after X seconds (1, in my case).
If the activity on top is not on the whitelist, we launch the blocking activity which pops up over whatever is currently running. The key part of the blocking activity is that it overrides onBackPressed, preventing the user from simply going back to the "bad" activity. Pressing the Home key is the only way (to my knowledge) to leave this screen.
Tips
Build a backdoor into the lock screen. For example, my solution prompts for a password on a long-press of the back key. After entering the correct password, the monitor service goes to sleep for 5 minutes so I can do my administrative work
Display the name of the blocked activity
Gather a good whitelist before turning this on! Activities you should definitely whitelist: the launcher, package installer, your own app (obviously), the browser, if your app has a web-based component
I don't like that my service is constantly looping in the background; it seems wasteful. I'd like to find some way to be notified when a new task is being launched, but I couldn't find a way to do that. The battery usage for my particular value of the monitor period and my particular phone is acceptable; though you should definitely test before adopting this yourself.
an efective solution,and here is the code from author's opinion
public class MonitorService extends Service {
private Handler handler;
Runnable runnable;
#Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();
handler = new Handler();
runnable = new Runnable() {
#Override
public void run() {
new Thread(new Runnable() {
#Override
public void run() {
ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
List<ActivityManager.RunningTaskInfo> taskInfo = am
.getRunningTasks(1);
ComponentName componentInfo = taskInfo.get(0).topActivity;
String currentActivityName=componentInfo.getClassName();
String packageName=componentInfo.getPackageName();
if(whitelist.contains(currentActivityName)){
Intent launchIntent = new Intent();
launchIntent.setComponent(new ComponentName(blockActivityPackageName,
blockActivityName));
launchIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(launchIntent);
}
}
}).start();
handler.postDelayed(this, 1000);
}
};
handler.postDelayed(runnable, 1000);
}
#Override
public void onStart(Intent intent, int startId) {
super.onStart(intent, startId);
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onDestroy() {
super.onDestroy();
Intent intent = new Intent(this, MonitorService.class);
startService(intent);
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return START_STICKY;
}
As you suggest, writing a custom launcher is probably would be cleaner; check out this open source launcher for reference http://code.google.com/p/adw-launcher-android/
Related
I am starting a service from my main Android activity as follows:
final Context context = base.getApplicationContext();
final Intent intent = new Intent(context, MyService.class);
startService(intent);
When I close the activity page by swiping it out from the recent apps list, the service stops running and restarts after some time. I can't use persistent services with notifications because of my app requirements. How can I make the service NOT restart or shutdown and just keep on running on app exit?
I'm in the same situation, so far I learned when the app is closed the service get closed also because they are in a one thread, so the service should be on another thread in order fot it not to be closed, look into that and look into keeping the service alive with alarm manager here an example http://www.vogella.com/articles/AndroidServices/article.html this way your service won't be shown in notification.
lastly, after all the research I've done I'm coming to realize that the best choice for a long running service is startForeground(), because it is made for that and the system actually deals with your service well.
make you service like this in your Mainifest
<service
android:name=".sys.service.youservice"
android:exported="true"
android:process=":ServiceProcess" />
then your service will run on other process named ServiceProcess
if you want make your service never die :
onStartCommand() return START_STICKY
onDestroy() -> startself
create a Deamon service
jin -> create a Native Deamon process, you can find some open-source projects on github
startForeground() , there is a way to startForeground without Notification ,google it
Services are quite complicated sometimes.
When you start a service from an activity (or your process), the service is essentially on the same process.
quoting from the developer notes
Most confusion about the Service class actually revolves around what it is not:
A Service is not a separate process. The Service object itself does not imply it is running in its own process; unless otherwise specified, it runs in the same process as the application it is part of.
A Service is not a thread. It is not a means itself to do work off of the main thread (to avoid Application Not Responding errors).
So, what this means is, if the user swipes the app away from the recent tasks it will delete your process(this includes all your activities etc).
Now, lets take three scenarios.
First where the service does not have a foreground notification.
In this case your process is killed along with your service.
Second where the service has a foreground notification
In this case the service is not killed and neither is the process
Third scenario
If the service does not have a foreground notification, it can still keep running if the app is closed. We can do this by making the service run in a different process.
(However, I've heard some people say that it may not work. left to you to try it out yourself)
you can create a service in a separate process by including the below attribute
in your manifest.
android:process=":yourService"
or
android:process="yourService" process name must begin with lower case.
quoting from developer notes
If the name assigned to this attribute begins with a colon (':'), a new process, private to the application, is created when it's needed and the service runs in that process. If the process name begins with a lowercase character, the service will run in a global process of that name, provided that it has permission to do so. This allows components in different applications to share a process, reducing resource usage.
this is what I have gathered, if anyone is an expert, please do correct me if I'm wrong :)
This may help you. I may be mistaken but it seems to me that this is related with returning START_STICKY in your onStartCommand() method. You can avoid the service from being called again by returning START_NOT_STICKY instead.
The Main problem is in unable to start the service when app closed, android OS(In Some OS) will kill the service for Resource Optimization, If you are not able to restart the service then call a alarm manger to start the receiver like this,Here is the entire code, This code will keep alive ur service.
Manifest is,
<service
android:name=".BackgroundService"
android:description="#string/app_name"
android:enabled="true"
android:label="Notification" />
<receiver android:name="AlarmReceiver">
<intent-filter>
<action android:name="REFRESH_THIS" />
</intent-filter>
</receiver>
IN Main Activty start alarm manger in this way,
String alarm = Context.ALARM_SERVICE;
AlarmManager am = (AlarmManager) getSystemService(alarm);
Intent intent = new Intent("REFRESH_THIS");
PendingIntent pi = PendingIntent.getBroadcast(this, 123456789, intent, 0);
int type = AlarmManager.RTC_WAKEUP;
long interval = 1000 * 50;
am.setInexactRepeating(type, System.currentTimeMillis(), interval, pi);
this will call reciver and reciver is,
public class AlarmReceiver extends BroadcastReceiver {
Context context;
#Override
public void onReceive(Context context, Intent intent) {
this.context = context;
System.out.println("Alarma Reciver Called");
if (isMyServiceRunning(this.context, BackgroundService.class)) {
System.out.println("alredy running no need to start again");
} else {
Intent background = new Intent(context, BackgroundService.class);
context.startService(background);
}
}
public static boolean isMyServiceRunning(Context context, Class<?> serviceClass) {
ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
List<ActivityManager.RunningServiceInfo> services = activityManager.getRunningServices(Integer.MAX_VALUE);
if (services != null) {
for (int i = 0; i < services.size(); i++) {
if ((serviceClass.getName()).equals(services.get(i).service.getClassName()) && services.get(i).pid != 0) {
return true;
}
}
}
return false;
}
}
And this Alaram reciver calls once when android app is opened and when app is closed.SO the service is like this,
public class BackgroundService extends Service {
private String LOG_TAG = null;
#Override
public void onCreate() {
super.onCreate();
LOG_TAG = "app_name";
Log.i(LOG_TAG, "service created");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i(LOG_TAG, "In onStartCommand");
//ur actual code
return START_STICKY;
}
#Override
public IBinder onBind(Intent intent) {
// Wont be called as service is not bound
Log.i(LOG_TAG, "In onBind");
return null;
}
#TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
#Override
public void onTaskRemoved(Intent rootIntent) {
super.onTaskRemoved(rootIntent);
Log.i(LOG_TAG, "In onTaskRemoved");
}
#Override
public void onDestroy() {
super.onDestroy();
Log.i(LOG_TAG, "In onDestroyed");
}
}
From Android O, you cant use the services for the long running background operations due to this, https://developer.android.com/about/versions/oreo/background . Jobservice will be the better option with Jobscheduler implementation.
try this, it will keep the service running in the background.
BackServices.class
public class BackServices extends Service{
#Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// Let it continue running until it is stopped.
Toast.makeText(this, "Service Started", Toast.LENGTH_LONG).show();
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
Toast.makeText(this, "Service Destroyed", Toast.LENGTH_LONG).show();
}
}
in your MainActivity onCreate drop this line of code
startService(new Intent(getBaseContext(), BackServices.class));
Now the service will stay running in background.
Using the same process for the service and the activity and START_STICKY or START_REDELIVER_INTENT in the service is the only way to be able to restart the service when the application restarts, which happens when the user closes the application for example, but also when the system decides to close it for optimisations reasons. You CAN NOT have a service that will run permanently without any interruption. This is by design, smartphones are not made to run continuous processes for long period of time. This is due to the fact that battery life is the highest priority. You need to design your service so it handles being stopped at any point.
You must add this code in your Service class so that it handles the case when your process is being killed
#Override
public void onTaskRemoved(Intent rootIntent) {
Intent restartServiceIntent = new Intent(getApplicationContext(), this.getClass());
restartServiceIntent.setPackage(getPackageName());
PendingIntent restartServicePendingIntent = PendingIntent.getService(getApplicationContext(), 1, restartServiceIntent, PendingIntent.FLAG_ONE_SHOT);
AlarmManager alarmService = (AlarmManager) getApplicationContext().getSystemService(Context.ALARM_SERVICE);
alarmService.set(
AlarmManager.ELAPSED_REALTIME,
SystemClock.elapsedRealtime() + 1000,
restartServicePendingIntent);
super.onTaskRemoved(rootIntent);
}
Why not use an IntentService?
IntentService opens a new Thread apart from the main Thread and works there, that way closing the app wont effect it
Be advised that IntentService runs the onHandleIntent() and when its done the service closes, see if it fits your needs.
http://developer.android.com/reference/android/app/IntentService.html
Best solution is to use the sync Adapter in android to start the service. Create a Sync Adapter and call start service their.. inside onPerformSync method. to create sync Account please refer this link https://developer.android.com/training/sync-adapters/index.html
Why SyncAdapter? Ans: Because earlier you used to start the service using your App context. so whenever your app process get killed (When u remove it from task manager or OS kill it because of lack of resources ) at that time your service will also be removed. SyncAdapter will not work in application thread.. so if u call inside it.. service will no longer be removed.. unless u write code to remove it.
<service android:name=".Service2"
android:process="#string/app_name"
android:exported="true"
android:isolatedProcess="true"
/>
Declare this in your manifest. Give a custom name to your process and make that process isolated and exported .
Running an intent service will be easier. Service in creating a thread in the application but it's still in the application.
Just override onDestroy method in your first visible activity like after splash you have home page and while redirecting from splash to home page you have already finish splash. so put on destroy in home page. and stop service in that method.
Refered to this library https://github.com/iammert/RadioPlayerService
I have this code for playing/pause radio
if (!mRadioManager.isPlaying())
mRadioManager.startRadio(RADIO_URL[0]);
else
mRadioManager.stopRadio();
and method for doing processes
#Override
public void onRadioStarted() {
runOnUiThread(new Runnable() {
#Override
public void run() {
//TODO Do UI works here.
mTextViewControl.setText("RADIO STATE : PLAYING...");
}
});
}
#Override
public void onRadioStopped() {
runOnUiThread(new Runnable() {
#Override
public void run() {
//TODO Do UI works here
mTextViewControl.setText("RADIO STATE : STOPPED.");
}
});
}
MyBroadcast Class
public class MyBroadcast extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Intent intent1 = new Intent(context, MainActivity.class);
intent1.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent1);
}
But in android 7 when i turn the screen off after 5-8 min radio stops playing music. I have done another example by doing in background and it is still the same thing. Please can anyone suggest me how to build a radio app without being affected by doze
You have to create Foreground Service for that. Usually when any long process is running (like downloading, playing music or vieo etc.) it creates notification in status bar and lock screen.
Note: You should only use a foreground service for tasks the user expects the system to execute immediately or without interruption. Such cases include uploading a photo to social media, or playing music even while the music-player app is not in the foreground. You should not start a foreground service simply to prevent the system from determining that your app is idle.
https://developer.android.com/guide/components/services.html#Foreground
The link below is an extensive example. Keep in mind that this requires another permission level.
https://developer.android.com/training/scheduling/wakelock.html
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();
}
I am starting a service from my main Android activity as follows:
final Context context = base.getApplicationContext();
final Intent intent = new Intent(context, MyService.class);
startService(intent);
When I close the activity page by swiping it out from the recent apps list, the service stops running and restarts after some time. I can't use persistent services with notifications because of my app requirements. How can I make the service NOT restart or shutdown and just keep on running on app exit?
I'm in the same situation, so far I learned when the app is closed the service get closed also because they are in a one thread, so the service should be on another thread in order fot it not to be closed, look into that and look into keeping the service alive with alarm manager here an example http://www.vogella.com/articles/AndroidServices/article.html this way your service won't be shown in notification.
lastly, after all the research I've done I'm coming to realize that the best choice for a long running service is startForeground(), because it is made for that and the system actually deals with your service well.
make you service like this in your Mainifest
<service
android:name=".sys.service.youservice"
android:exported="true"
android:process=":ServiceProcess" />
then your service will run on other process named ServiceProcess
if you want make your service never die :
onStartCommand() return START_STICKY
onDestroy() -> startself
create a Deamon service
jin -> create a Native Deamon process, you can find some open-source projects on github
startForeground() , there is a way to startForeground without Notification ,google it
Services are quite complicated sometimes.
When you start a service from an activity (or your process), the service is essentially on the same process.
quoting from the developer notes
Most confusion about the Service class actually revolves around what it is not:
A Service is not a separate process. The Service object itself does not imply it is running in its own process; unless otherwise specified, it runs in the same process as the application it is part of.
A Service is not a thread. It is not a means itself to do work off of the main thread (to avoid Application Not Responding errors).
So, what this means is, if the user swipes the app away from the recent tasks it will delete your process(this includes all your activities etc).
Now, lets take three scenarios.
First where the service does not have a foreground notification.
In this case your process is killed along with your service.
Second where the service has a foreground notification
In this case the service is not killed and neither is the process
Third scenario
If the service does not have a foreground notification, it can still keep running if the app is closed. We can do this by making the service run in a different process.
(However, I've heard some people say that it may not work. left to you to try it out yourself)
you can create a service in a separate process by including the below attribute
in your manifest.
android:process=":yourService"
or
android:process="yourService" process name must begin with lower case.
quoting from developer notes
If the name assigned to this attribute begins with a colon (':'), a new process, private to the application, is created when it's needed and the service runs in that process. If the process name begins with a lowercase character, the service will run in a global process of that name, provided that it has permission to do so. This allows components in different applications to share a process, reducing resource usage.
this is what I have gathered, if anyone is an expert, please do correct me if I'm wrong :)
This may help you. I may be mistaken but it seems to me that this is related with returning START_STICKY in your onStartCommand() method. You can avoid the service from being called again by returning START_NOT_STICKY instead.
The Main problem is in unable to start the service when app closed, android OS(In Some OS) will kill the service for Resource Optimization, If you are not able to restart the service then call a alarm manger to start the receiver like this,Here is the entire code, This code will keep alive ur service.
Manifest is,
<service
android:name=".BackgroundService"
android:description="#string/app_name"
android:enabled="true"
android:label="Notification" />
<receiver android:name="AlarmReceiver">
<intent-filter>
<action android:name="REFRESH_THIS" />
</intent-filter>
</receiver>
IN Main Activty start alarm manger in this way,
String alarm = Context.ALARM_SERVICE;
AlarmManager am = (AlarmManager) getSystemService(alarm);
Intent intent = new Intent("REFRESH_THIS");
PendingIntent pi = PendingIntent.getBroadcast(this, 123456789, intent, 0);
int type = AlarmManager.RTC_WAKEUP;
long interval = 1000 * 50;
am.setInexactRepeating(type, System.currentTimeMillis(), interval, pi);
this will call reciver and reciver is,
public class AlarmReceiver extends BroadcastReceiver {
Context context;
#Override
public void onReceive(Context context, Intent intent) {
this.context = context;
System.out.println("Alarma Reciver Called");
if (isMyServiceRunning(this.context, BackgroundService.class)) {
System.out.println("alredy running no need to start again");
} else {
Intent background = new Intent(context, BackgroundService.class);
context.startService(background);
}
}
public static boolean isMyServiceRunning(Context context, Class<?> serviceClass) {
ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
List<ActivityManager.RunningServiceInfo> services = activityManager.getRunningServices(Integer.MAX_VALUE);
if (services != null) {
for (int i = 0; i < services.size(); i++) {
if ((serviceClass.getName()).equals(services.get(i).service.getClassName()) && services.get(i).pid != 0) {
return true;
}
}
}
return false;
}
}
And this Alaram reciver calls once when android app is opened and when app is closed.SO the service is like this,
public class BackgroundService extends Service {
private String LOG_TAG = null;
#Override
public void onCreate() {
super.onCreate();
LOG_TAG = "app_name";
Log.i(LOG_TAG, "service created");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i(LOG_TAG, "In onStartCommand");
//ur actual code
return START_STICKY;
}
#Override
public IBinder onBind(Intent intent) {
// Wont be called as service is not bound
Log.i(LOG_TAG, "In onBind");
return null;
}
#TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
#Override
public void onTaskRemoved(Intent rootIntent) {
super.onTaskRemoved(rootIntent);
Log.i(LOG_TAG, "In onTaskRemoved");
}
#Override
public void onDestroy() {
super.onDestroy();
Log.i(LOG_TAG, "In onDestroyed");
}
}
From Android O, you cant use the services for the long running background operations due to this, https://developer.android.com/about/versions/oreo/background . Jobservice will be the better option with Jobscheduler implementation.
try this, it will keep the service running in the background.
BackServices.class
public class BackServices extends Service{
#Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// Let it continue running until it is stopped.
Toast.makeText(this, "Service Started", Toast.LENGTH_LONG).show();
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
Toast.makeText(this, "Service Destroyed", Toast.LENGTH_LONG).show();
}
}
in your MainActivity onCreate drop this line of code
startService(new Intent(getBaseContext(), BackServices.class));
Now the service will stay running in background.
Using the same process for the service and the activity and START_STICKY or START_REDELIVER_INTENT in the service is the only way to be able to restart the service when the application restarts, which happens when the user closes the application for example, but also when the system decides to close it for optimisations reasons. You CAN NOT have a service that will run permanently without any interruption. This is by design, smartphones are not made to run continuous processes for long period of time. This is due to the fact that battery life is the highest priority. You need to design your service so it handles being stopped at any point.
You must add this code in your Service class so that it handles the case when your process is being killed
#Override
public void onTaskRemoved(Intent rootIntent) {
Intent restartServiceIntent = new Intent(getApplicationContext(), this.getClass());
restartServiceIntent.setPackage(getPackageName());
PendingIntent restartServicePendingIntent = PendingIntent.getService(getApplicationContext(), 1, restartServiceIntent, PendingIntent.FLAG_ONE_SHOT);
AlarmManager alarmService = (AlarmManager) getApplicationContext().getSystemService(Context.ALARM_SERVICE);
alarmService.set(
AlarmManager.ELAPSED_REALTIME,
SystemClock.elapsedRealtime() + 1000,
restartServicePendingIntent);
super.onTaskRemoved(rootIntent);
}
Why not use an IntentService?
IntentService opens a new Thread apart from the main Thread and works there, that way closing the app wont effect it
Be advised that IntentService runs the onHandleIntent() and when its done the service closes, see if it fits your needs.
http://developer.android.com/reference/android/app/IntentService.html
Best solution is to use the sync Adapter in android to start the service. Create a Sync Adapter and call start service their.. inside onPerformSync method. to create sync Account please refer this link https://developer.android.com/training/sync-adapters/index.html
Why SyncAdapter? Ans: Because earlier you used to start the service using your App context. so whenever your app process get killed (When u remove it from task manager or OS kill it because of lack of resources ) at that time your service will also be removed. SyncAdapter will not work in application thread.. so if u call inside it.. service will no longer be removed.. unless u write code to remove it.
<service android:name=".Service2"
android:process="#string/app_name"
android:exported="true"
android:isolatedProcess="true"
/>
Declare this in your manifest. Give a custom name to your process and make that process isolated and exported .
Running an intent service will be easier. Service in creating a thread in the application but it's still in the application.
Just override onDestroy method in your first visible activity like after splash you have home page and while redirecting from splash to home page you have already finish splash. so put on destroy in home page. and stop service in that method.
Application thread get close if its killed by task manager. Need to re-invoke application as though its killed by other application or task manager. Any idea?
You have to run background service with START_STICKY command.
Just extends Service and override onCommand like this :
#Override
public int onStartCommand(Intent intent,int flags,int startId) {
super.onStartCommand(intent, flags, startId);
return START_STICKY;
}
Like this your Service is restart when it's close (by system or anything else)
You just have now check on your service (onCreate for example) if application is running or not and launch it again if not. I suppose PackageManager let you check this or simply put a static boolean is_alive to see if your activity is always running.
Regards
Jim
Bug in Android 2.3 with START_STICKY
I needed to keep alive a Service with all my forces. If the service is running anytime you can pop the UI.
onDestroy()
it will re-launch.
Can't be uninstalled the app, because it has a Device Administrator.
It is a kind of parental control, the user knows it is there.
Only way to stop is to remove the Device Admin, and uninstall it, but removing Device Admin will lock the phone as Kaspersky how it does.
There are a loot of braodcast receivers, such as boot finshed, user presen, screen on, screen off... , many other, all starting the service, you can do it with UI too. Or in the service check if your activity alive , visible, if not, than pop it.
I hope you will use with good reason the info!
Edit: Restart service code snippet:
// restart service:
Context context = getApplicationContext();
Intent myService = new Intent(context, MyService.class);
context.startService(myService);
Edit2: add spippet to check if the service is running in ... a load of Broadcasts
public static boolean isMyServiceRunning(Context context) {
ActivityManager manager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
if (MyService.class.getName().equals(service.service.getClassName())) {
Log.d("myTag", "true");
return true;
}
}
Log.d("myTag", "false");
return false;
}
Edit3 other service start:
public static void startTheService(Context context) {
Intent myService = new Intent(context, MyService.class);
context.startService(myService);
}
Dont't forget Android 2.3 bug: do the logic for initialization in
#Override
public void onCreate()
and not in:
#Override
public int onStartCommand(Intent intent, int flags, int startId)
While look at Google IO official product source code I have found the following
((AlarmManager) context.getSystemService(ALARM_SERVICE))
.set(
AlarmManager.RTC,
System.currentTimeMillis() + jitterMillis,
PendingIntent.getBroadcast(
context,
0,
new Intent(context, TriggerSyncReceiver.class),
PendingIntent.FLAG_CANCEL_CURRENT));
URL for code
You can start a sticky service and register an alarm manager that will check again and again that is your application is alive if not then it will run it.
You can also make a receiver and register it for <action android:name="android.intent.action.BOOT_COMPLETED" /> then you can start your service from your receiver. I think there should be some broadcast message when OS or kills some service/application.
Just to give you a rough idea I have done this and its working
1) register receiver
Receiver Code:
#Override
public void onReceive(Context context, Intent intent) {
try {
this.mContext = context;
startService(intent.getAction());
uploadOnWifiConnected(intent);
} catch (Exception ex) {
Logger.logException(ex);
Console.showToastDelegate(mContext, R.string.msg_service_starup_failure, Toast.LENGTH_LONG);
}
}
private void startService(final String action) {
if (action.equalsIgnoreCase(ACTION_BOOT)) {
Util.startServiceSpawnProcessSingelton(mContext, mConnection);
} else if (action.equalsIgnoreCase(ACTION_SHUTDOWN)) {
}
}
Service Code:
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Logger.logInfo("Service Started onStartCommand");
return Service.START_STICKY;
}
I prefer doing nothing in onStartCommand because it will get called each time you start service but onCreate is only called 1st time service is started, so I do most of the code in onCreate, that way I don't really care about weather service is already running or not.
according to #RetoMeyer from Google, the solution is to make the app "sticky".
for this, you must establisH START_STICKY in your intent service management.
check this reference from developer android
Yes, Once memory low issue comes android os starts killing application to compensate the required memory. Using services you can achieve this, your service should run parallely with your application but see, some of the cases even your service will be also killed at the same time. After killing if memory is sufficient android os itself try to restart the application not in all the cases. Finally there is no hard and fast rule to re-invoke your application once killed by os in all the cases it depends on os and internal behaviours.