I've got a Service in my Android application. During onStartCommand, I pass the Service object to another class. Then, from there, there's a thread that after 30 seconds starts another Service. It is something like this:
public class FooService extends Service {
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
MyClass mc = new MyClass(this);
mc.testMethod();
stopSelf();
return START_NOT_STICKY;
}
}
And this is MyClass:
public class MyClass {
private Service service;
public MyClass(Service service) {
this.service = service;
}
public void testMethod() {
new Thread(new Runnable() {
#Override
public void run() {
try {
Thread.sleep(20*1000);
Intent intent = new Intent(service, BarService.class);
service.startService(intent);
}
catch (Exception e) {
// CATCH!
}
}
}).start();
}
}
Now, as you can see, in FooService I call stopSelf() wich destroys that Service object. By the way MyClass has got a copy of that Service that was passed by value. After 20 seconds, we can start BarService from MyClass. I've tested it and it works but I can't understand why! The way I wrote the code is dirty (for me). Is it correct to start another service from one that was destroyed? Thank you for your help.
I've tested it and it works but I can't understand why
It works today on the environments you tested in. It may not work in all environments (e.g., ROM mods) and may not work tomorrow (e.g., Android OS updates). A destroyed Context, such as your stopped service, should not be used for anything. It happens that presently you can still use it to call startService() later, but that behavior is not guaranteed.
Is it correct to start another service from one that was destroyed?
No. In this case, I fail to see why you need two services in the first place.
I've got a copy of that service
No, you do not.
Related
I'm trying to create a service which will run a socket for receiver data when the app is closed.
According to this thread on Github Flutter should provide an abstraction for background execution, flutter doesn't have an abstraction that executes a code in the background, so I'm writing a native code.
The service opens up correctly, but as soon as the app is closed, it gets moved to cache services and after approximately 5 minutes it is ended.
I found this background_service MainActivity.java, but I'm not using the notification example contained in that repository. (The service contained in this repository also gets terminated once the app is closed.
The example plugin for this article as well.
I still don't have a concrete plan to make the socket connection in the service. I actually would like to call the socket_io_client function within the service, sort of like a callback, but I'm not sure if it will work.
So I just want to know if it is possible to keep the service running after the app is closed. If yes, how?
MainActivity.java
public class MainActivity extends FlutterActivity {
private static final String CHANNEL = "com.retroportalstudio.www.background_service";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Intent forService = new Intent(this, MyService.class);
forService.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
new MethodChannel(getFlutterView(), CHANNEL).setMethodCallHandler(new MethodChannel.MethodCallHandler() {
#Override
public void onMethodCall(MethodCall methodCall, MethodChannel.Result result) {
if (methodCall.method.equals("startService")) {
startService(forService);
result.success("Service Started");
}
}
});
}
}
public class MyService extends Service {
// #Override
// public int onStartCommand(Intent intent, int flags, int startId) {
// return START_STICKY;
// }
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
}
Hi all i did research more than a lot but no one give me the right answer .
I am surprised because my question is so simple ,but didn't found a single solution.
I found a lots of question like mine but people making their answer round and round ,i am really sick of this now this is my last and final try
i will appreciate if any of you resolve it
Let me light up mu Question again in Brief:
i just want to make a simple service which hear the power button (really so simple) ,Now i did that easy thing , i mean i made a service with a broadcast receiver ok (Quite Simple) , and it run well , But!!! whenever i kill the app from background task , then the service stopped automatically , what i want here , that killing the task do not effect my service (how simple is this)
(Note: 1. i already used START_STICKY and Service.START_STICKY
2.Also i did a bad thing that is is called service in onDestroy.
But Still got thumbs down.
)
Please give me a fine solution
I will only appreciate after answer
(Because i am really so sick of this )
Here is my Code
MainActivity
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
startService(new Intent(this, MyService.class));
}
MyService:
public class MyService extends Service {
private BroadcastReceiver mReceiver = null;
public MyService() {
}
#Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
throw new UnsupportedOperationException("Not yet implemented");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return Service.START_STICKY;
}
#Override
public void onCreate() {
IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
mReceiver = new ScreenReceiver();
registerReceiver(mReceiver, filter);
}
#Override
public void onDestroy() {
super.onDestroy();
}
}
ScreenReceiver:
public class ScreenReceiver extends BroadcastReceiver {
public static boolean wasScreenOn = true;
#Override
public void onReceive(final Context context, final Intent intent) {
if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
Log.e("LightWriter", "I WORK BRO.");
wasScreenOn = false;
} else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
Log.e("LightWriter", "I WORK BRO.");
wasScreenOn = true;
}
}}
I am felling so dumb about this , hey i got the answer
1. Those who think that its not possible are wrong
i just try with other device and it works well
the issue with my device is i have marshmallow , so if any one have it allow permission from permission manager (works fine ).
Thanks for your time:)
I'm writing an app which should collect some sensor data every 10 seconds or so and write them to disk.
So far, I have an Activity which starts a service. The service has a runnable, which uses a handler to run my task periodically via handler.postDelayed(). See below for the (shortened) code.
So far, this works fine as long as the device is active. As soon as the device goes into idle, it doesn't run my task until it wakes up again.
So, my question is how to run my task ALWAYS.
With setExactAndAllowWhileIdle(), the AlarmManager seems to offer exactly what I need, but...
To reduce abuse, there are restrictions on how frequently these alarms will go off for a particular application. Under normal system operation, it will not dispatch these alarms more than about every minute (at which point every such pending alarm is dispatched); when in low-power idle modes this duration may be significantly longer, such as 15 minutes.
Battery life has just a minor priority, though not being awake the entire time would be fine. (Not sure if android can be awake for just a second or so)
MyActivity
...
public void onStartService(View view) {
Intent i= new Intent(getBaseContext(), MyAppService.class);
getBaseContext().startService(i);
}
public void onStopService(View view) {
stopService(new Intent(getBaseContext(), MyAppService.class));
}
....
MyService
public class MyAppService extends Service {
MyRunnable mr;
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
mr= new MyRunnable(getApplicationContext() );
mr.Start();
return Service.START_NOT_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
mr.Stop();
}
#Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
throw new UnsupportedOperationException("Not yet implemented");
}
}
MyRunnable
public class MyRunnable implements Runnable{
// context is needed for sensorListener (?)
private Context myContext;
private Handler handler;
public MyRunnable(Context c){
myContext=c;
handler= new Handler();
}
public void Start(){
run();
}
public void Stop(){
handler.removeCallbacks(this);
// some clean-up
}
#Override
public void run() {
//acquire and write to file some sensor data
handler.postDelayed(this, 10000);
}
}
i think what you are looking for is STICKY SERVICE.
Officail Docs: If the system kills the service after onStartCommand() returns, recreate the service and call onStartCommand(), but do not redeliver the last intent. Instead, the system calls onStartCommand() with a null intent, unless there were pending intents to start the service, in which case, those intents are delivered. This is suitable for media players (or similar services) that are not executing commands, but running indefinitely and waiting for a job.
you just need to pass a flag at the time of calling the service.
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 have an intentservice that gets qued by the user and by my app automatically. I need to be able to kill all pending intents that are qued when the user logs out of my application, but I cannot seem to get that to work. I have tried stopService() and stopself(), but the intents continue to fire off the intentservice after the user has logged out. I would try to get the id of the intent but that is difficult as everytime the intentservice starts, the variable holding the intent id's is empty. Here is my intentservice code:
public class MainUploadIntentService extends IntentService {
private final String TAG = "MAINUPLOADINTSER";
private GMLHandsetApplication app = null;
private SimpleDateFormat sdf = null;
public boolean recStops = true;
public MainUploadIntentService() {
super("Main Upload Intent Service");
GMLHandsetApplication.writeToLogs(TAG,
"GMLMainUploadIntentService Constructor");
}
#Override
protected void onHandleIntent(Intent intent) {
GMLHandsetApplication.writeToLogs(TAG, "onHandleIntent Started");
if (app == null) {
app = (GMLHandsetApplication) getApplication();
}
uploadData(app);
GMLHandsetApplication.writeToLogs(TAG, "onHandleIntent Finished");
}
#Override
public void onDestroy() {
GMLHandsetApplication.writeToLogs(TAG, "onDestroy Started");
app = null;
stopSelf();
GMLHandsetApplication.writeToLogs(TAG, "onDestroy completed");
}
public void uploadData(GMLHandsetApplication appl) {
//All of my code that needs to be ran
}
Unfortunately, I don't think it's possible to accomplish that with the standard IntentService methods since it doesn't offer a way to interrupt it while it's already going.
There are a few options I can think of that you can try to see if they fit your need.
Copy the IntentService code to make your own modifications to it that would allow you to remove pending messages. Looks like someone had some success with that here: Android: intentservice, how abort or skip a task in the handleintent queue
Instead of copying all the IntentService code, you might also be able to Bind to it like a normal Service (since IntentService extends Service) so you can write your own function to remove pending messages. This one is also mentioned in that link.
Rewrite the IntentService as a regular Service instead. With this option, you'd have more control over adding and removing messages.
I had what sounds like a similar situation where I was using an IntentService, and I eventually just converted it to a Service instead. That let me run the tasks concurrently and also cancel them when I needed to clear them.
Here
When should I free the native (Android NDK) handles? is the HangAroundIntentService class that has the method cancelQueue().
The class also has the method
public static Intent markedAsCancelIntent(Intent intent)
that converts an intent into a cancel intent, and
public static boolean isCancelIntent(Intent intent).
The class is based on the open-sourced Google's code.
Just a thought but inside of your onhandleintent can you have an argument that checks to see if app is running if not then don't run the code? example. In the start of your app you could have a static var
boolean appRunning;
Next in your onhandle of the intent, when you set the appRunning to false, after an onPause or onDestroy of activity, you could wrap the onhandleintent code in a boolean:
protected void onHandleIntent(final Intent intent) {
if(MainActivity.appRunning){
...
}
}
Just a thought