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Can't cancel a notification after updating it

I'm developing a countdown app, and currently trying to show a notification when you exit the app while the countdown is running. Correspondingly, I want the notification to disappear when the user returns to the app.
So far I've managed to make it work for a simple notification with static text, do the following: in MainActivity.java, in onStop(), I create an intent and initiate the service with startService(intent). Symmetrically, in onStart() I run stopService(intent) so that when you return to the app the service gets canceled. This works like a charm, the notification appears and disappears when it must.
The next step has been trying to make the notification show a text that varies (it will say "X minutes remaining"). According to the info out there, to update an existing notification you have to create a new one, give it the same ID as the existing one, and call .notify of a NotificationManager. When I do this the notification indeed gets updated correctly (the text changes as expected), BUT: now, returning to the main activity does not cancel the notification. The icon stays up there and doesn't get interrupted.
I've been trying to solve this for hours and hours. I've also tried hacks like sending signals via shared preferences to tell the service to stop, but for some reason, it seems to completely ignore the command stopself() too.
Does anybody have a suggestion of what could be the cause? Any help would be greatly appreciated. Here is the relevant code:
MainActivity.java:
#Override
protected void onStart() {
super.onStart();
Intent serviceIntent = new Intent(getBaseContext(), CounterService.class);
stopService(serviceIntent);
}
protected void onStop() {
super.onStop();
Intent serviceIntent = new Intent(getBaseContext(), CounterService.class);
startService(serviceIntent);
}
CounterService.java:
public class CounterService extends Service {
Notification notification;
NotificationManager notificator;
Intent intentNoti;
CountDownTimer counter;
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onCreate() {
super.onCreate();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
intentNoti = new Intent(this, MainActivity.class);
final PendingIntent pending = PendingIntent.getActivity(this, 0, intentNoti, 0);
final Bitmap icon = BitmapFactory.decodeResource(getResources(),
R.drawable.common_full_open_on_phone);
//Countdown
counter = new CountDownTimer (30000, 1000) {
public void onTick(long millisUntilFinished) {
String time = String.valueOf(System.currentTimeMillis());
notification = new Notification.Builder(CounterService.this)
.setContentTitle("Name")
.setContentText(time)
.setSmallIcon(R.drawable.icon_start)
.setLargeIcon(Bitmap.createScaledBitmap(icon, 128, 128, false))
.setContentIntent(pending)
.setOngoing(true).build();
notificator = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
notificator.notify(1001, notification);
}
public void onFinish() {
}
}.start();
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
counter.cancel();
}
}

First create a Timer like this
private Timer timer;
private TimerTask timerTask;
public void startTimer() {
timer = new Timer();
timerTask = new TimerTask() {
public void run() {
// Add your code
}
};
timer.schedule(timerTask, 1000, 1000); //
}
Also you need to stop your timer.
So
public void stoptimertask() {
if (timer != null) {
timer.cancel();
timer = null;
}
}
Call StartTimer and StopTimer in OnStartCommand() and onDestroy() respectively. Add these lines in onDestroy()
Intent broadcastIntent = new Intent();
broadcastIntent.setAction("restartservice");
broadcastIntent.setClass(this, Restarter.class);
this.sendBroadcast(broadcastIntent);

it can be handled in multiple ways, you have not stopped your timer
Note:- posting code in Kotlin
1)
override fun onDestroy() {
counter.cancel()
}
in your activity
override fun onResume() {
super.onResume()
val notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
notificationManager.cancelAll()
}

How to pass a variable from activities to start a CountDownTimer service?

This is my first question and I've been trying to find a solution to this for hours but can't get it to work. I'm building an android app that takes an input from the user (number of hours) to fast (not eat). The input is then taken to the service where it does a countdown in the background. Along the way, I'd like the user to access other activities that could you the results from the countdown timer (eg, time_left/total_time = percentage complete). So far, my button that I've created works to make the call for the service. but the service never gets called to update the text view. Thanks
Here is what I have,
public class StartFast extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_start_fast);
startService(new Intent(this, MyService.class));
Log.i("Started service", "hello started service...");
registerReceiver(br, new IntentFilter("COUNTDOWN_UPDATED"));
}
private BroadcastReceiver br = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
intent.getExtras();
long millisUntilFinished = intent.getLongExtra("countdown",0);
String time = Long.toString((millisUntilFinished));
TextView tv = findViewById(R.id.timeView1);
tv.setText(time);
}
};
public void BeginFast(View view){
//Intent intent = new Intent( this, StartFast.class);
// below is how to pass an intent for use in a Service to run in the backgroun
Intent intent =new Intent(this, MyService.class);
startService(intent);
// intent.putExtra() // putExtra longs ...will do after static run succeeds
//intent.putExtra("data", data); //adding the data
Intent intent1 = new Intent(this, Heart.class);
startActivity(intent1);
}
}
and here is the service class,
public class MyService extends Service {
private final static String TAG = "MyService";
public static final String COUNTDOWN_BR = "FastBreak.countdown_br";
Intent bi = new Intent(COUNTDOWN_BR);
CountDownTimer cdt = null;
public void OnCreate(){
super.onCreate();
Log.i(TAG, "starting timer...");
cdt = new CountDownTimer(30000,1000) {
#Override
public void onTick(long millisUntilFinished){
Log.i(TAG, "Countdown seconds remaining: " +millisUntilFinished /1000);
bi.putExtra("countdown", millisUntilFinished);
sendBroadcast(bi);
}
#Override
public void onFinish(){
Log.i(TAG, "Timer finished");
}
};
cdt.start();
}
#Override
public void onDestroy() {
cdt.cancel();
Log.i(TAG, "Timer cancelled");
super.onDestroy();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return super.onStartCommand(intent, flags, startId);
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}

https://github.com/greenrobot/EventBus
Check this out. This library is the best and easiest implementation of broadcasts. You can send any data to any object (StartFast service in your case) from any other object (StartFast activity in your case) and write code to run.

First, you need to start the service and register it in the manifest. After the service is started by an activity, it will keep running in the background.
You can send intents with a service and anybody who has registered a broadcast receiver listening to that intent can hear it.
Let's say FirstActivity started the service and registers receiver listening to intent with the tag BOBBY. The service is the one sending an intent BOBBY to anyone who is interested and has registered for it.
You want to move on to SecondActivity. Before you do that, onPause of FirstActivity you need to unregister that broadcastreceiver.
SecondActivity is interested in the intent with tag BOBBY, so he creates his own broadcast receiver and registers for it.
I hope you can see where this is going.A broadcastreceiver can listen to all sorts of intents that you make up.
Have fun.

Send data to activity from already running sticky service

I created sticky background service, that should be started on boot:
public class AutostartReceiver extends BroadcastReceiver
{
public AutostartReceiver()
{
}
#Override
public void onReceive(Context context, Intent intent)
{
context.startService(new Intent(context, MyService.class));
}
}
My service is intended to do some work in background, it's implemented by creating thread for this. Also there is Messenger class used for sending work status to my main activity:
#Override
public int onStartCommand(Intent intent, int flags, int startId)
{
Log.i(TAG, "Service onStartCommand " + startId);
final int currentId = startId;
Messenger callback = null;
if(intent!=null)
{
callback = intent.getParcelableExtra("messenger");
}
final Messenger finalCallback = callback;
Runnable r = new Runnable()
{
public void run()
{
... do something, then stop
stopSelf();
}
};
if(t == null)
{
t = new Thread(r);
t.start();
}
return Service.START_STICKY;
}
Main activity receives messages sent from background thread running inside my service (some commands, that service is sending periodically:
Handler mHandler = new Handler()
{
#Override
public void handleMessage(Message msg)
{
switch (msg.what)
{
case 0:
Toast.makeText(MainActivity.this,"Service runing", Toast.LENGTH_LONG).show();
break;
}
}
};
This works only if I start my service from activity, with activity's context. Obviously, if service is started on boot, or my app was closed (removed from last app list) and opened again, my activity is unable to get any messages from service any more.
If I invoke start service while service is already running, it will simply run OnStartCommand again, so either new thread will be created (I don't want it) or I need to destroy running thread and run thread again.
Is there any way to get my activity receiving messages from service, without actually touching already running thread inside it? I know about bound services, but it's not clear for me how to use them in my specific case.

As Alternate way You can use LocalBroadcastManager to send Data from Service to Activity.
Broadcast Your message from Service:
private void broadcastMessage(Context context){
Intent intent = new Intent("UI_UPDATE_BROADCAST");
intent.putExtra("MESSAGE", "MyMessage");
LocalBroadcastManager.getInstance(context).sendBroadcast(intent);
}
Register Broadcast Receiver in your activity to receive messages:
#Override
public void onResume() {
super.onResume();
LocalBroadcastManager.getInstance(mContext).registerReceiver(mMessageReceiver, new IntentFilter("UI_UPDATE_BROADCAST"));
}
#Override
public void onPause() {
super.onPause();
LocalBroadcastManager.getInstance(mContext).unregisterReceiver(mMessageReceiver);
}
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
//Do Something With Received Data
String msg = intent.getStringExtra("MESSAGE");
}
};

I would use a broadcast receiver for Service-to-Activity communication.
Code:
public class MyActivity extends Activity {
private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
//Toast here
}
#Override
protected void onCreate(Bundle savedInstanceState) {
LocalBroadcastManager.getInstance(this).registerReceiver(broadcastReceiver, new IntentFilter("message-name"));
}
#Override
public void onDestroy() {
LocalBroadcastManager.getInstance(this).unregisterReceiver(broadcastReceiver);
super.onDestroy();
}
}
Then in your service you would broadcast the message like this:
Intent intent = new Intent("message-name");
intent.putExtra("data", 1);
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);

Creating a background service that launches an app at a specific time.

I just started on android development and I'm trying to write and a service that runs in the background and will launch an app at a specific time.
The program I wrote is based on a tutorial I came across, basically the app has 2 buttons, a start and stop. Once the user presses the start button, it'll start the background service and will check the time and if the time is right, it'll launch the app.
However I noticed that it doesn't always checks the time, it only does it when the user presses the button. How do I make it so that, it'll keep checking the time, once the user presses the button?.
Here is my code.
MyService.java
public class MyService extends Service{
private static final String TAG = "MyService";
#Override
public IBinder onBind(Intent arg0) {
return null;
}
#Override
public void onCreate() {
//Toast.makeText(this, "Congrats! MyService Created", Toast.LENGTH_LONG).show();
Log.d(TAG, "onCreate");
}
#Override
public void onStart(Intent intent, int startId) {
//Toast.makeText(this, "My Service Started", Toast.LENGTH_LONG).show();
startApp("com.example.myApp");
Log.d(TAG, "onStart");
}
#Override
public void onDestroy() {
Toast.makeText(this, "MyService Stopped", Toast.LENGTH_LONG).show();
Log.d(TAG, "onDestroy");
}
public void startApp(String packageName){
Calendar c = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm");
String strDate = sdf.format(c.getTime());
if(strDate == "09:00" || strDate == "15:00" || strDate == "21:00"){
Toast.makeText(this,strDate,Toast.LENGTH_LONG).show();
Toast.makeText(this,"Starting the App",Toast.LENGTH_LONG).show();
Intent intent = getPackageManager().getLaunchIntentForPackage(packageName);
if(intent != null){
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
}
}
}
}
MainActivity.Java
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
//start the service
public void onClickStartServie(View V)
{
//start the service from here
startService(new Intent(this, MyService.class));
}
//Stop the started service
public void onClickStopService(View V)
{
//Stop the running service from here
//Service will only stop if it is already running.
stopService(new Intent(this, MyService.class));
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}

I think using alarm manager will be a better option. Set an alarm for that time and receive broadcast in your receiver at that time like below code:
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, AppConstants.ALARM_ID_TESTING, new Intent(
AppConstants.FILTER_TESTING), PendingIntent.FLAG_UPDATE_CURRENT);
alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + millisAfterCurrent, pendingIntent);
Add receiver in manifest:
<receiver
android:name=“TestReceiver"
<intent-filter>
<action android:name="filter.test.time” />
</intent-filter>
And receiver class as:
class TestReceiver extends BroadcastReceiver
{
#Override
public void onReceive(Context context, Intent intent)
{
if (intent.getAction().equals(AppConstants.FILTER_TESTING))
{
// code here
}
}
}

Why dont you try Time Changed Receiver instead of service, Since using a background service is bad programming approah.A service keeps on running in background and takes a lot of system memory and a burden battery. Moreover system can stop any of extra services running at anytime for adjustment of memory issues.
A time change receiver is the best approach and in that you can compare time and open any app accordingly.

i suggest you this two ways:
Use the "new" ScheduledThreadPoolExecutor as replacement for Timer
Example:
int threadCount = 1;
ScheduledThreadPoolExecutor service = new ScheduledThreadPoolExecutor(threadCount);
long initialDelay = 5;
long period = 10;
ScheduledFuture<?> task = service.scheduleAtFixedRate(new Runnable() {
#Override
public void run() {
// DO IT EVERY 10 SECONDS
}
}, initialDelay, period, TimeUnit.SECONDS);
[...]
//if you want you can cancel the task later
task.cancel(true); // mayInterruptIfRunning = true
Since Activities, Threads and Processes can be terminated anytime by Android OS it is not guaranteed that the job is always executed.
Therefore, it is better to use AlarmManager
Official howto: Scheduling Repeating Alarms
Another nice example: Repeat Alarm Example In Android Using AlarmManager

EventListener for Power Button press in a Service

I want to listen the power key event in the service.
How can in do that ?
Currently I am working with an app, where I need to listen the power button for some events, from a service which is running in a background, even when the app is killed or stopped.
Somehow I can manage to get it.
But when I kill/stop the app, the service is getting stopped.
How can i overcome this ?
Currently the code i am using this :
Service Class:
public class SampleService extends Service
{
SettingContentObserver mSettingsContentObserver;
AudioManager mAudioManager;
private ComponentName mRemoteControlResponder;
private Intent intent;
#Override
public int onStartCommand(Intent intent, int flags, int startId)
{
Log.v("StartServiceAtBoot", "StartAtBootService -- onStartCommand()");
// We want this service to continue running until it is explicitly
// stopped, so return sticky.
return START_STICKY;
}
#Override
public void onStart(Intent intent, int startId) {
boolean screenOn = intent.getBooleanExtra("screen_state", false);
if (!screenOn) {
Toast.makeText(getApplicationContext(), "On", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(), "Off", Toast.LENGTH_SHORT).show();
}
}
public void onCreate()
{
mSettingsContentObserver = new SettingContentObserver(this,new Handler());
getApplicationContext().getContentResolver().registerContentObserver
(android.provider.Settings.System.CONTENT_URI, true, mSettingsContentObserver );
mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
mRemoteControlResponder = new ComponentName(getPackageName(),
StartAtBootServiceReceiver.class.getName());
IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
BroadcastReceiver mReceiver = new StartAtBootServiceReceiver();
registerReceiver(mReceiver, filter);
}
#Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
public void onDestroy()
{
getApplicationContext().getContentResolver().unregisterContentObserver(mSettingsContentObserver);
}
}
BroadcastReceiver Class:
public class StartAtBootServiceReceiver extends BroadcastReceiver
{
static boolean wasScreenOn;
private boolean screenOff;
public void onReceive(Context context, Intent intent)
{
if(intent.getAction().equals(Intent.ACTION_SCREEN_OFF))
{
wasScreenOn = false;
Toast.makeText(context, "Power Off", Toast.LENGTH_SHORT).show();
}
else if(intent.getAction().equals(Intent.ACTION_SCREEN_ON))
{
wasScreenOn = true;
}
Intent i = new Intent(context, SampleService.class);
i.putExtra("screen_state", screenOff);
i.setAction("com.example.antitheft.SampleService");
context.startService(i);
//
if (intent.getAction().equals(Intent.ACTION_BOOT_COMPLETED)) {
Intent i1 = new Intent();
i1.setAction("com.example.sampleonkeylistener.MainActivity");
context.startService(i1);
}
}
}
given above is the sample code and i have created AndroidManifest.xml files also with user's permission but i cannot get the app continue service if it is killed or stopped.
Thanks in Advance.

#Override
public void onDestroy() {
super.onDestroy();
startService(new Intent(this, SampleService.class));
}
This is one way to ensure that service will never stop even user want to destroy it.
This is one Just ONE of ways to achieve what you are trying to achieve.
Secondly, you can try and run service in "foreground" by using startForeground().
Also, make sure that in you return "START_STICKY" (which you are doing in the sample code that you shared and I trust that you are also doing in App's code too :) ) in Services's onStartCommand().
This will ensure that If this service's process is killed while it is started (after returning from onStartCommand(Intent, int, int)), then leave it in the started state but don't retain this delivered intent. Later the system will try to re-create the service.
And you may find some additional pointers/hints to make sure your service is not stopped at below link.
How can we prevent a Service from being killed by OS?
Just pick and choose the approach that best suits YOUR Need/implementation.