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.
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.
I am checking Internet connectivity in my app using BroadcastReceiver and I show an alert dialog if the connection is lost. It works fine. But my problem is that BroadcastReceiver works even if my app is in backgroung. So dialog pops up when internet connection is lost even if user is in some other app. This is totally ruining my app.
Has anyone got any idea how to restrict Broadcast receiver in the app only?
Here is my BroadcastReceiver :
public class ConnectivityChangedReceiver extends BroadcastReceiver{
#Override
public void onReceive( Context context, Intent intent )
{
ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService( Context.CONNECTIVITY_SERVICE );
NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
if (networkInfo != null && networkInfo.isConnected()) {
} else {
try{
Intent i=new Intent(context, InternetDialogActivity.class);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);
} catch(Exception e){
e.printStackTrace();
}
}
}
}
And the activity is:
public class InternetDialogActivity extends Activity implements OnClickListener{
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.internet_dialog_box);
getWindow().setLayout(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
Button retryButton = (Button) findViewById(R.id.retryInternetButton);
retryButton.setOnClickListener(this);
}
public boolean checkConnectivity(){
ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
if (networkInfo!=null && networkInfo.isConnected()) {
finish();
return true;
} else {
Intent intent = getIntent();
finish();
startActivity(intent);
return false;
}
}
#Override
public void onClick(View view) {
switch(view.getId()){
case R.id.retryInternetButton:
try{
checkConnectivity();
} catch(Exception e){
e.printStackTrace();
}
break;
}
}
}
Here is how I declared receiver and activity in manifest:
<receiver android:name="com.lisnx.service.ConnectivityChangedReceiver"
android:label="NetworkConnection">
<intent-filter>
<action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
</intent-filter>
</receiver>
<activity android:name="com.lisnx.activity.InternetDialogActivity"
android:configChanges="orientation|keyboardHidden"
android:theme="#android:style/Theme.Dialog" />
I have read that we can restrict BroadcastReceiver to work within the app by not declaring it in the manifest. But I don't know how will receiver work then? Please help me. I am stuck on it badly. Thanx in advance.
A BroadcastReceiver works when the app is in the background because the event that the receiver picks up are sent globally, and each app is registered to listen in on these, regardless of whether or not it is running.
To deal with this, in your BroadcastReceiver's onReceive code, check if your app is in the foreground.
There is one--and only one that I know of--consistently effective method to do this. You need to keep track of your pause/resume actions for your application. Ensure that you check this in every activity.
There is some sample code in this answer (solution #1). In your case, you would want to check MyApplication.isActivityVisible() == true as a validation before doing anything from your BroadcastReceiver.
Have you tried to remove the Intent filter from the manifest and register/unregister it in activity? So you can try to register Intent filter in onStart() and unregister it on onStop() methods. The code goes somethink like this:
static final String ACTION = "android.net.conn.CONNECTIVITY_CHANGE";
IntentFilter filter = new IntentFilter(ACTION);
this.registerReceiver(ConnectivityChangedReceiver, filter);
unregisterReceiver(ConnectivityChangedReceiver);
You should also learn about Activity Lifecycle, if it's not familiar yet.
You should register/unregister your BroadcastReceiver in onPause() and onResume() of each activity. Then you know that the receiver is only "listening" when your app is in the foreground. You can easily do that by creating your own BaseActivity that extends Activity and overrides onPause() and onResume() and registers/unregisters your receiver. Just have all your activities extend BaseActivity and have them call through to super.onResume() and super.onPause() as usual. Here's example code:
public class BaseActivity extends Activity {
// Create an IntentFilter to listen for connectivity change events
static IntentFilter filter = new IntentFilter("android.net.conn.CONNECTIVITY_CHANGE");
// Create an instance of our BroadcastReceiver
static ConnectivityChangedReceiver receiver = new ConnectivityChangedReceiver();
#Override
protected void onPause() {
super.onPause();
// Stop listening for connectivity change events
unregisterReceiver(receiver);
}
#Override
protected void onResume() {
super.onResume();
// Listen for connectivity change events
registerReceiver(receiver, filter);
}
}
All your activities should extend BaseActivity and if they need to do anything special in onResume() or onPause() just make sure to call through to super.onXXXXX() like this:
public MyActivity extends BaseActivity {
#Override
protected void onResume() {
super.onResume();
// Here you do whatever you need to do in onResume() of your activity
...
}
#Override
protected void onPause() {
super.onPause();
// Here you do whatever you need to do in onPause() of your activity
...
}
}
I didn't run the code through a compiler so I apologize if there's a typo or I missed something.
I think you will have to make sure that you are not using the receiver when app is in background. For that you will have to use every activities onPause() and onResume() methods.
As far as I know, if Broadcast receiver is registered inside manifest.xml then broadcast receiver exists as long as application exists. Also, Dynamically registered receivers (that means, Register your BroadcastReceiver programmatically) are called on the UI thread. This means that your receivers blocks any UI handling and thus the onReceive() method should be as fast as possible.
However, I will try to discuss information about Broadcast Receiver. But, first should know some information. Firstly, Broadcast receiver is a standalone application component which means it will continue running even when other application component are not running. That's why we unregister broadcast receiver in onPause on the activity. Also, Developer should register this in Activity.onResume() implementation.
Secondly, Developer should not unregister in Activity.onSaveInstanceState(), because this won't be called if the user moves back in the history stack. I have put that information from BroadcastReceiver documentation.
Another point is that a BroadcastReceiver object is only valid for the duration of the call to onReceive(). As soon as the onReceive() method is finished, your BroadcastReceiver terminates.
Now, how to register your receiver programmatically:
public abstract Intent registerReceiver (BroadcastReceiver receiver, IntentFilter filter)
Here, BroadcastReceiver- receiver will be call when any broadcast intent match with filter.
And IntentFilter- Intent specifies which event your receiver should listen to.
Register:
YourConnectionListener receiver;
this.reciever = new YourConnectionListener();
IntentFilter filter = new IntentFilter();
filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
registerReceiver(this.reciever, filter);
Sent your Broadcast Info:
Intent intent = new Intent();
intent.putExtra("Message", "Your connectivity info has Changed!!");
this.sendBroadcast(intent);
Receiver:
Now, need to receive the Broadcast. Android calls the onReceive() method on all registered broadcast receivers whenever the event occurs. Say you want to be notified whenever the connection is changed.
public class YourConnectionListener extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent){
// your Code
}
}
onReceive() has two arguments:
context: The Context object you can use to access additional information or to start services or activities.
intent: Intent used to register your receiver. This object contains additional information that you can use in your implementation.
Additionally, Developer should avoid any long-lasting tasks in your BroadcastReceiver. So, In statically and dynamically registered receivers, Developer should do minor tasks in the receiver itself.For any longer tasks you should start a service from within your receiver.
To make a Broadcast Receiver that fires only when you app is running follow the below code.
1. Create your Broadcast Receiver like this:
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
public class InternetStatusNotifier extends BroadcastReceiver{
#Override
public void onReceive(Context context, Intent intent) {
//Recieve notification here
}
}
2. Make an activity or fragment where you want the Broadcast Receiver to work like this:
import android.app.Activity;
import android.content.IntentFilter;
import android.os.Bundle;
public class MainActivity extends Activity {
private InternetStatusNotifier mInternetStatusNotifier;
#Override
protected void onCreate(Bundle savedInstanceState) {
mInternetStatusNotifier = new InternetStatusNotifier();
super.onCreate(savedInstanceState);
}
#Override
protected void onResume() {
registerReceiver(mInternetStatusNotifier, new IntentFilter(
"android.net.conn.CONNECTIVITY_CHANGE"));
super.onResume();
}
#Override
protected void onPause() {
unregisterReceiver(mInternetStatusNotifier);
super.onPause();
}
Note: That is how you use broadcasts receiver in a screen specific manner. Only the screen displaying will receive broadcasts in this way. When you register broadcast using manifest file then they are even received when app is closed
That is the way broadcast receivers work in Android. If you register for a broadcast in the manifest and your app is not running, Android will start a new process to handle the broadcast. It is generally a bad idea to directly show a UI from a broadcast receiver, because this may interrupt other apps. I'm also not convinced that a universal 'connection lost' dialog is a good idea either. This should probably be handled by each activity that uses network access.
As for the original question, you need to disable your receiver when your activity goes in the background (onPause(), etc.) and enable it when you come to the foreground (onResume(), etc). Put enabled=false in your manifest and then use something like this in your code to toggle it as necessary:
public static void toggle(Context context, boolean enable) {
int flag = enable ? PackageManager.COMPONENT_ENABLED_STATE_ENABLED
: PackageManager.COMPONENT_ENABLED_STATE_DISABLED;
ComponentName receiver = new ComponentName(context,
ConnectivityMonitor.class);
context.getPackageManager().setComponentEnabledSetting(receiver, flag,
PackageManager.DONT_KILL_APP);
}
A simple way of finding whether the app is in foreground or not
if((mContext.getPackageName().equalsIgnoreCase(
((ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE))
.getRunningTasks(1).get(0).topActivity.getPackageName())))
{
//app is in foreground;
}
I better suggest you to check the internet setting from the application when someone opens it, here is the piece of code how i do it.
public static boolean isNetworkConnected(Context ctx) {
ConnectivityManager cm = (ConnectivityManager) ctx.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo ni = cm.getActiveNetworkInfo();
if (ni == null) {
return false; // There are no active networks.
} else
return true;
}
I have an IntentService that is started from an Activity and I would like to be able to stop the service immediately from the activity with a "cancel" button in the activity. As soon as that "cancel" button is pressed, I want the service to stop executing lines of code.
I've found a number of questions similar to this (i.e. here, here, here, here), but no good answers. Activity.stopService() and Service.stopSelf() execute the Service.onDestroy() method immediately but then let the code in onHandleIntent() finish all the way through before destroying the service.
Since there is apparently no guaranteed way to terminate the service's thread immediately, the only recommended solution I can find (here) is to have a boolean member variable in the service that can be switched in the onDestroy() method, and then have just about every line of the code in onHandleIntent() wrapped in its own "if" clause looking at that variable. That's an awful way to write code.
Does anybody know of a better way to do this in an IntentService?
Here is the trick, make use of a volatile static variable and check continue condition in some of lines in your service that service continue should be checked:
class MyService extends IntentService {
public static volatile boolean shouldContinue = true;
public MyService() {
super("My Service");
}
#Override
protected void onHandleIntent(Intent intent) {
doStuff();
}
private void doStuff() {
// do something
// check the condition
if (shouldContinue == false) {
stopSelf();
return;
}
// continue doing something
// check the condition
if (shouldContinue == false) {
stopSelf();
return;
}
// put those checks wherever you need
}
}
and in your activity do this to stop your service,
MyService.shouldContinue = false;
Stopping a thread or a process immediately is often a dirty thing. However, it should be fine if your service is stateless.
Declare the service as a separate process in the manifest:
<service
android:process=":service"
...
And when you want to stop its execution, just kill that process:
ActivityManager am = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
List<RunningAppProcessInfo> runningAppProcesses = am.getRunningAppProcesses();
Iterator<RunningAppProcessInfo> iter = runningAppProcesses.iterator();
while(iter.hasNext()){
RunningAppProcessInfo next = iter.next();
String pricessName = getPackageName() + ":service";
if(next.processName.equals(pricessName)){
Process.killProcess(next.pid);
break;
}
}
I've used a BroadcastReceiver inside the service that simply puts a stop boolean to true. Example:
private boolean stop=false;
public class StopReceiver extends BroadcastReceiver {
public static final String ACTION_STOP = "stop";
#Override
public void onReceive(Context context, Intent intent) {
stop = true;
}
}
#Override
protected void onHandleIntent(Intent intent) {
IntentFilter filter = new IntentFilter(StopReceiver.ACTION_STOP);
filter.addCategory(Intent.CATEGORY_DEFAULT);
StopReceiver receiver = new StopReceiver();
registerReceiver(receiver, filter);
// Do stuff ....
//In the work you are doing
if(stop==true){
unregisterReceiver(receiver);
stopSelf();
}
}
Then, from the activity call:
//STOP SERVICE
Intent sIntent = new Intent();
sIntent.setAction(StopReceiver.ACTION_STOP);
sendBroadcast(sIntent);
To stop the service.
PD: I use a boolean because In my case I stop the service while in a loop but you can probably call unregisterReceiver and stopSelf in onReceive.
PD2: Don't forget to call unregisterReceiver if the service finishes it's work normally or you'll get a leaked IntentReceiver error.
#Override
protected void onHandleIntent(Intent intent) {
String action = intent.getAction();
if (action.equals(Action_CANCEL)) {
stopSelf();
} else if (action.equals(Action_START)) {
//handle
}
}
Hope it works.
In case of IntentService it does not stop or takes any other request through some intent action until its onHandleIntent method completes the previous request.
If we try to start IntentService again with some other action, onHandleIntent will be called only when previous intent / task is finished.
Also stopService(intent); or stopSelf(); does not work until the onHandleIntent() method finishes its task.
So I think here better solution is to use normal Service here.
I hope it will help!
If using an IntentService, then I think you are stuck doing something like you describe, where the onHandleIntent() code has to poll for its "stop" signal.
If your background task is potentially long-running, and if you need to be able to stop it, I think you are better off using a plain Service instead. At a high level, write your Service to:
Expose a "start" Intent to start an AsyncTask to perform your background work, saving off a reference to that newly-created AsyncTask.
Expose a "cancel" Intent to invoke AsyncTask.cancel(true), or have onDestroy() invoke AsyncTask.cancel(true).
The Activity can then either send the "cancel" Intent or just call stopService().
In exchange for the ability to cancel the background work, the Service takes on the following responsibilities:
The AsyncTask doInBackground() will have to gracefully handle InterruptedException and/or periodically check for Thread.interrupted(), and return "early".
The Service will have to ensure that stopSelf() is called (maybe in AsyncTask onPostExecute/onCancelled).
As #budius already mentioned in his comment, you should set a boolean on the Service when you click that button:
// your Activity.java
public boolean onClick() {
//...
mService.performTasks = false;
mService.stopSelf();
}
And in your Intent handling, before you do the important task of committing/sending the intent information, just use that boolean:
// your Service.java
public boolean performTasks = true;
protected void onHandleIntent(Intent intent) {
Bundle intentInfo = intent.getBundle();
if (this.performTasks) {
// Then handle the intent...
}
}
Otherwise, the Service will do it's task of processing that Intent. That's how it was meant to be used,
because I can't quite see how you could solve it otherwise if you look at the core code.
Here is some sample code to start/stop Service
To start,
Intent GPSService = new Intent(context, TrackGPS.class);
context.startService(GPSService);
To stop,
context.stopService(GPSService);
context.stopService(GPSService);
I'm using C2DM, my BroadcastReceivers propagate the C2DM events to a local service. the service complete the registration by sending the id to my webserver pus it's responsible for letting the device know about new messages, however if the application (one of the activities) is up we want to send an intent to that activity with the new data so it can be updated, if not than the NotificationManager is used to notify the user.
The issue is, how to know the activity is running ? the Application object is not an option since the Service is part of the application it's obviously going to be present. unregister in the onDesroy of each application is also not an option since it may occur in orientation change...
Any standard way to get it done ?
Solution 1:
You can use ActivityManager for Checking if Activity is Running or not:
public boolean isActivityRunning() {
ActivityManager activityManager = (ActivityManager)Monitor.this.getSystemService (Context.ACTIVITY_SERVICE);
List<RunningTaskInfo> activitys = activityManager.getRunningTasks(Integer.MAX_VALUE);
isActivityFound = false;
for (int i = 0; i < activitys.size(); i++) {
if (activitys.get(i).topActivity.toString().equalsIgnoreCase("ComponentInfo{com.example.testapp/com.example.testapp.Your_Activity_Name}")) {
isActivityFound = true;
}
}
return isActivityFound;
}
need to add the permission to your manifest..
<uses-permission android:name="android.permission.GET_TASKS"/>
Solution 2:
Your can use an static variable in your activity for which you want to check it's running or not and store it some where for access from your service or broadcast receiver as:
static boolean CurrentlyRunning= false;
public void onStart() {
CurrentlyRunning= true; //Store status of Activity somewhere like in shared //preference
}
public void onStop() {
CurrentlyRunning= false;//Store status of Activity somewhere like in shared //preference
}
I hope this was helpful!
The next approach would work well if you want to handle incoming Google Cloud message (C2DM) by your activity (if any is running) or issue a notification if no activities are running.
Register one BroadcastReceiver in the manifest file. This receiver will handle C2D messages whenever application not running. Register another BroadcastReceiver programmatically in your activity. This receiver will handle C2D messages whenever activity is running.
AndoroidManifest.xml
<receiver
android:name=".StaticReceiver"
android:permission="com.google.android.c2dm.permission.SEND" >
<intent-filter>
<action android:name="com.google.android.c2dm.intent.RECEIVE" />
<category android:name="com.mypackage" />
</intent-filter>
</receiver>
MyReceiver.java
public class StaticReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
// TODO Trigger a Notification
}
}
MyActivity.java
public class MyActivity extends ActionBarActivity {
#Override
protected void onResume() {
super.onResume();
final IntentFilter filter = new
IntentFilter("com.google.android.c2dm.intent.RECEIVE");
filter.addCategory("com.mypackage");
filter.setPriority(1);
registerReceiver(dynamicReceiver, filter,
"com.google.android.c2dm.permission.SEND", null);
}
#Override
protected void onPause() {
super.onPause();
unregisterReceiver(dynamicReceiver);
}
private final BroadcastReceiver dynamicReceiver
= new BroadcastReceiver()
{
#Override
public void onReceive(Context context, Intent intent) {
// TODO Handle C2DM
// blocks passing broadcast to StaticReceiver instance
abortBroadcast();
}
};
}
Note! To catch broadcasts first, the priority of dynamicReceiver IntentFilter must be higher than priority of StaticReceiver instance IntentFilter (default priority is '0').
PS. It looks like broadcasts issued by Google Cloud Messaging Service are ordered broadcasts. Original idea author: CommonsWare
Copied from here.
you can use a static variable within the activity.
class MyActivity extends Activity {
static boolean active = false;
public void onStart() {
active = true;
}
public void onStop() {
active = false;
}
}
Easiest way to check that whether an Activity is running or not is:
Context context = MyActivity.this;
if (! ((Activity) context).isFinishing()) {
// Activity is running
} else {
// Activity has been finished
}
Note: If activity is not running you should not perform any UI related operation.