Develop Reference

What kind of services should I use for accessing sensors data in background?

I successfully used a service to do a certain task in the foreground. Now, to do it in the background, I'd remove the handler.removeCallbacks method in onDestroy().
But this would also prevents me from stopping the service using stopService(intent).
I saw on the official docs that I should maybe use JobScheduler (as I target API 28).
Here is a more precise indication of my code :
public class MainActivity {
private Intent intent;
onCreate() {
if (intent == null) {
intent = new Intent(this, MyService.class);
}
}
startService(intent);
... // Then is some code to stop the service if needed with stopService(intent)
}
--------------------------------------------------------------
public class myService {
private Handler handler = null;
private static Runnable runnable = null;
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onCreate() {
handler = new Handler();
runnable = new Runnable() {
#Override
public void run() {
System.out.println("Running service times " + i);
i++;
handler.postDelayed(runnable, 1000);
}
};
handler.post(runnable);
}
#Override
public void onDestroy() {
handler.removeCallbacks(runnable);
super.onDestroy();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return super.onStartCommand(intent, flags, startId);
}
I would like it to run in the background (even if the device is locked) but still being able to disable the service (or JobScheduler?).
What are your suggestions?

you can use work manager
or job dispatcher
and there is a lot of options like
SyncAdapter, Bound services, Intent Service
you can use one of these options according to your need

Android: Service is killed and restarted after a while

I know that is a well known subject, but I have tried lot of things. I have an simple application, dedicated to a specific user, application has an mainActivity which is displaying some status on screen and it's starting two services, one is making request from a server (at every 5 minutes) and one which is sending sms and replay to server (at every ten minutes).
The application is running on a Samsung pocket 2 with Android 4.4.2, this device is used only for this application. While the device is connected to ADB the services are working just fine, but if I disconnect the phone and let it running normally, the services are killed repeatable and restarted after a while. The messaged are send with very much delay. I would be thankful for any suggestions.
Here is my code:
Main activity:
public class MainActivity extends Activity {
private TextView _internet;
private TextView _signal;
private TextView _server;
private BroadcastReceiver receiver;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
IntentFilter intentFilter = new IntentFilter(Constants.SS);
receiverWorker();
registerReceiver(receiver, intentFilter);
startService(new Intent(this, RefreshDBService.class));
startService(new Intent(this, SmsService.class));
}
private void receiverWorker() {
receiver = new BroadcastReceiver() {
public void onReceive(Context arg0, Intent arg1) {
checkState();
}};
}
public void refreshButonClicked(View v) {
checkState();
}`
Here is my first service:
public class RefreshDBService extends Service {
private Thread _backgroundWork;
private ScheduledExecutorService scheduleTaskExecutor = Executors.newScheduledThreadPool(1);
private DataBaseOperations _dataSource;
#Override
public void onCreate() {
super.onCreate();
_dataSource = new DataBaseOperations(this);
_backgroundWork = new Thread(new Runnable() {
#Override
public void run() {
if(Checks.checkInternetConnection(getApplicationContext())){
if(ServerOperations.isServerAvailable(getApplicationContext())){
String inputData = ServerOperations.makeRequest(Constants.GET_DATA_ROUTE, ServerOperations.getMessagesFromServer(getApplicationContext()));
ArrayList<DataSmsObj> dataFromServer=null;
if(inputData!=null && !inputData.isEmpty()){
dataFromServer = ServerOperations.fromJsonToObjects(inputData);
if(dataFromServer.size()>0){
_dataSource.open();
_dataSource.insertDataFromServer(dataFromServer);
_dataSource.close();
}
}
System.out.println("check server for messages in pending status, received -> "+ dataFromServer.size());
}else{
System.out.println("no server");
sentErrorToUI(Constants.NO_SERVER);
}
}else{
System.out.println("no internet");
sentErrorToUI(Constants.NO_INTERNET);
}
}
});
}
public int onStartCommand(Intent intent, int flags, int startId) {
scheduleTaskExecutor.scheduleWithFixedDelay(_backgroundWork, 0, Constants.NEXT_CYCLE/2, TimeUnit.MINUTES);
return START_REDELIVER_INTENT;
}
#Override
public void onDestroy() {
super.onDestroy();
scheduleTaskExecutor.shutdownNow();
}
public IBinder onBind(Intent intent) {
return null;
}
private void sentErrorToUI(String message){
Intent intent = new Intent(Constants.SS);
intent.putExtra(Constants.SS, message);
System.out.println("trimit" +message);
sendBroadcast(intent);
}
}
And this is the second one:
public class SmsService extends Service {
private Thread _backgroundWork;
private ScheduledExecutorService scheduleTaskExecutor = Executors.newScheduledThreadPool(1);
private DataBaseOperations _dataSource;
#Override
public void onCreate() {
super.onCreate();
_dataSource = new DataBaseOperations(this);
_backgroundWork = new Thread(new Runnable() {
#Override
public void run() {
sendFeedbackToServer();
List<DataSmsObj> dataToSent = new ArrayList<DataSmsObj>();
_dataSource.open();
dataToSent = _dataSource.getDataToSent();
_dataSource.close();
System.out.println("messages to sent: "+ dataToSent.size());
for (int i = 0; i < dataToSent.size(); i++) {
//here the messages are send, the code is to long to put it here, but if is need i can do it afterwards
}
}
});
}
public int onStartCommand(Intent intent, int flags, int startId) {
scheduleTaskExecutor.scheduleWithFixedDelay(_backgroundWork, 0, Constants.NEXT_CYCLE, TimeUnit.MINUTES);
return START_REDELIVER_INTENT;
}
#Override
public void onDestroy() {
super.onDestroy();
scheduleTaskExecutor.shutdownNow();
public IBinder onBind(Intent intent) {
return null;
}

If you are using a background Service with a scheduled task, it could be killed by the system. The only way to prevent the killing is a foreground Service. Quoting the documentation:
A foreground service is a service that the user is actively aware of and is not a candidate for the system to kill when low on memory.
You have to call the method startForeground() inside your Service using a Notification to show it. For further information you can check: https://developer.android.com/guide/components/services.html#Foreground
By the way, I recommend you to use the new JobScheduler api above api 21.
https://developer.android.com/reference/android/app/job/JobScheduler.html

Android kills service based on priority stack.
Android: keeping a background service alive (preventing process death)
What is START_STICKY,START_NOT_STICKY and START_REDELIVER_INTENT Service
Above links might help you.

Your devices will sleeps if it is unplugged from computer . So, the solutions :
Use startForeground method to prevent service to be killed and/or use AlarmManager in order to charge event.
It is possible to use start_stiky flag but it just restarts the process if it killed by system.

How do I stop my thread and will my service stop too if I do?

I'm currently working on my first android app and I've run into a problem.
My app is supposed to be counting in the background using a Service and I'm creating a new thread to handle that. If I don't stop the thread in my Service's onDestroy() method, my phone gives me the message "Unfortunately, (my app) has stopped." every time I close the app. I need to stop it somehow, and I tried to do it using :
while(!Thread.currentThread().isInterrupted()){
**my code**
}:
And then interrupting it in the onDestroy() method.
It works, but it makes my app count extremely fast, so I would like to know if it can be done any other way that does not change the functionaliy of my code.
Also, since my thread gets stopped in the onDestroy method, I guess my service stops as well. Is there any way to keep my service running even when my app has been closed?
Here's my code:
public class CounterService extends Service {
private Handler handler;
private int time = -1;
private boolean isActive;
private Intent timeBroadcaster;
private Runnable counter;
private Thread serviceCounter;
#Override
public void onCreate(){
super.onCreate();
handler = new Handler();
timeBroadcaster = new Intent();
timeBroadcaster.setAction("EXAMPLE_BROADCAST");
counter = new Runnable() {
#Override
public void run() {
isActive = ((PowerManager) getSystemService(Context.POWER_SERVICE)).isInteractive();
if (isActive) {
handler.postDelayed(this, 1000);
time += 1;
} else {
if (time > 5) {
//log
}
time = 0;
handler.postDelayed(this, 1000);
}
timeBroadcaster.putExtra("counter", time);
sendBroadcast(timeBroadcaster);
}
};
serviceCounter = new Thread(counter);
serviceCounter.start();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return super.onStartCommand(intent, flags, startId);
}
#Override
public void onDestroy(){
//serviceCounter.interrupt();
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
}

Is there any way to keep my service running even when my app has been closed?
you can use sync adapter which runs in background even app is stoped.
https://developer.android.com/training/sync-adapters/creating-sync-adapter.html

Service with Async Task isn't starting

I'm using the below code to start a service. this service should start Async task that checks mysql and provide notifications. the service isn't starting and I can't find why? I receive no Log from the service.
(when I call the Async task from main activity directly without service it works fine).
Main Activity code:
Intent startIntent = new Intent(MainActivity.this, ForegroundService.class);
MainActivity.this.startService(startIntent);
Service Class Code:
public class ForegroundService extends Service {
private static final String LOG_TAG = "ForegroundService";
#Override
public void onCreate() {
Log.i(LOG_TAG, "On Create");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i(LOG_TAG, "On Start");
new Thread(new Runnable() {
#Override
public void run() {
String newoperator = "Go";
TimeSync ReportCheck= new TimeSync(getApplicationContext());
ReportCheck.execute(newoperator);
}
}).start();
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
Log.i(LOG_TAG, "In onDestroy");
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
}
I also found some solutions adding the below command in main activity but the command isn't applicable in my android studio.
startIntent.setAction(Constants.ACTION.STARTFOREGROUND_ACTION);

What version of android studio do you use? Have you tried to updated to the latest version?
Download Android Studio 2.1

Android - how to run a task via "handler" periodically within a service-intent (worker-thread)

My question is Android related:
How do I run a task every 20 seconds within an intentservice ?
Problem is, I have to init some classes which will be used in the Handler "run" process.
It works one time - but then the service stops & the application crashes when the handler-loop starts again after 20 seconds (probably because of the classes that got eliminated when the service stopped?). So maybe the solution is to get the service to stay running as long as the Handler runs or to throw away the code and do it right ?
Hope, someone can help me.
public class Fadenzieher extends IntentService{
private Handler handler = new Handler();
private Runnable timedTask = new Runnable(){
#Override
public void run() {
// My functions get called here...
// class1member.getDBWorkdone();
handler.postDelayed(timedTask, 20000);
handler.obtainMessage();
}};
public Fadenzieher() {
super("Fadenzieher");
}
#Override
protected void onHandleIntent(Intent intent) {
// SOME INITIALISING
// I have to init some vars & functions here that
// will also be used inside the handler loop
// Class1 class1member = new Class1();
// class1member.startUpDB();
handler.post(timedTask); }
Thank you very much in advance!!!
---- So this is the updated code now (14. nov. 2011)
public class Fadenzieher extends Service{
private static final long UPDATE_INTERVAL = 60000;
Context context = this;
private Timer timer = new Timer();
DbHelper dbHelper;
public void onCreate(){
dbHelper = new DbHelper(context);
runTheLoop();
}
protected void runTheLoop() {
timer.scheduleAtFixedRate(new TimerTask(){
#Override
public void run() {
dbHelper.dosomethings();
Toast.makeText(context, "CALL", Toast.LENGTH_LONG).show();
}}, 0, UPDATE_INTERVAL);
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Toast.makeText(this, "Starte Service“, Toast.LENGTH_SHORT).show();
return super.onStartCommand(intent,flags,startId);
}
public void onDestroy() {
super.onDestroy();
dbHelper.close();
Toast.makeText(this, "Stoppe Service“, Toast.LENGTH_LONG).show();
}
// We return the binder class upon a call of bindService
#Override
public IBinder onBind(Intent arg0) {
return mBinder;
}
public class MyBinder extends Binder {
Fadenzieher getService() {
return Fadenzieher.this;
}
}
}
The whole application crashes immediately.

How do I run a task every 20 seconds within an intentservice ?
That is not an appropriate use of IntentService. Use a regular Service, please.
It works one time - but then the service stops & the application crashes when the handler-loop starts again after 20 seconds
IntentService shuts down when onHandleIntent() returns, which is why this is breaking for you. Use a regular Service, please.
Also:
Please allow the user to configure the polling period
Make sure that this service will shut down when the user no longer wants it to be running