Develop Reference

My service works with android 7.1.1 but not with android 9

My app uses a background service to listen to GPS position changes. It works on android 7.1.1 (even if my activity is closed or the screen is turn off). When I tried it on android 9 (with the AVD) it only works when the activity is in the foreground, otherwise not. It looks like the service is stopped when the app is closed. minSdkVersion is set to 23. Why app have different behavior on different API? Android does not guarantee the compatibility of apps on newer OS versions?
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/**code to request permission*/
startService(new Intent(this, EventControllerService.class));
}
}
public final class EventControllerService extends Service {
private final static int MIN_TIME_FOR_GPS_UPDATES = 1;
private final static float MIN_METER_FOR_GPS_UPDATES = 10.0f;
private static NotificationManager mNotificationManager;
private final BroadcastReceiver receiverDNDChange = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
//work on receive
}
};
private final EventControllerService self = this;
private final LocationListener locationListener = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
Toast.makeText(self, "DENTRO", Toast.LENGTH_LONG).show();
try {
//work to do on position change
} catch (SecurityException ignored) {
stopSelf();
}
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
}
};
#Override
public void onCreate() {
super.onCreate();
try {
mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
IntentFilter filter = new IntentFilter();
filter.addAction(NotificationManager.ACTION_INTERRUPTION_FILTER_CHANGED);
registerReceiver(receiverDNDChange, filter);
LocationManager mLocationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME_FOR_GPS_UPDATES, MIN_METER_FOR_GPS_UPDATES, locationListener);
} catch (SecurityException ignored) {
stopSelf();
}
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
}
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="marcomantovani.pcd.silentmap">
<uses-permission android:name="android.permission.ACCESS_NOTIFICATION_POLICY" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme"
tools:ignore="AllowBackup,GoogleAppIndexingWarning">
<service android:name=".EventControllerService"/>
<receiver android:name="marcomantovani.pcd.silentmap.AutoStart">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
How can I change code to avoid this problem?

I understand you read this:
https://developer.android.com/about/versions/oreo/background
There are many changes related to background services and especially GPS in Android 9. Note this also (so targeting API23 is not a solution):
By default, these changes only affect apps that target Android 8.0 (API level 26) or higher. However, users can enable these restrictions for any app from the Settings screen, even if the app targets an API level lower than 26. You may need to update your app to comply with the new limitations.
What you can do right now and how we make it work in our apps. Migrate your service to compatible with Android 9. I suggest using:
startForegroundService()
Make your service to run on foreground. It's a small change. Just change one flag nad start your service this way.
Show notification that your app is working (this will keep your app working even when user is leaving the app otherwise - Android OS will limit your service)
Targeting API23 is a bad idea also because of this:
Starting August 1, 2019, Google Play requires that new apps target at least Android 9.0 (API level 28), and that app updates target Android 9.0 from November 1, 2019. Until these dates, new apps and app updates must target at least Android 8.0 (API level 26).
TL;DR
1. Migrate service to foreground
2. Create simple notification that will tell your user that app is working
3. Start service with startForeground()

Android has been steadily moving to restrict the access given to an app in the background. Location services were restricted from Android 8.
Reference:
https://developer.android.com/about/versions/oreo/android-8.0-changes#abll

How to Avoid Killing Background Service Even App is Killed in Marshmallow?

I want to create a android app to track real time location with a android service. But when i kill the app from recent app list, Service also killed in android 6 (Huawei y3 2017). But same code works on android 8. Please help me to solve my problem. Please find below is my code.
I added START_STICKY and START_REDELIVER_INTENT flags in onStartCommand method.
I have tried to restart the service in onTaskRemoved method.
Tried to add android:process attribute to
Manifest.xml
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".Login" />
<activity android:name=".Home" />
<service
android:name=".TrackingService"
android:enabled="true"
android:exported="true" />
</application>
This is how start my service in Home activity
Intent intent = new Intent(Home.this, TrackingService.class);
startService(intent);
TrackingService.java service file
#Override
public void onCreate(){
buildNotification();
requestLocationUpdates();
Toast.makeText(getBaseContext(), "Service Started", Toast.LENGTH_SHORT).show();
super.onCreate();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId){
return START_STICKY;
}
private void buildNotification() {
Random random = new Random();
int m = random.nextInt(9999 - 1000) + 1000;
String stop = "stop";
registerReceiver(stopReceiver, new IntentFilter(stop));
PendingIntent broadcastIntent = PendingIntent.getBroadcast(this, 0, new Intent(stop), PendingIntent.FLAG_UPDATE_CURRENT);
Notification.Builder builder = new Notification.Builder(this)
.setContentTitle(getString(R.string.app_name))
.setContentText(getString(R.string.tracking_enabled_notif))
.setOngoing(true)
.setContentIntent(broadcastIntent);
startForeground(m, builder.build());
}
protected BroadcastReceiver stopReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
unregisterReceiver(stopReceiver);
stopSelf();
}
};
private void requestLocationUpdates() {
LocationRequest request = new LocationRequest();
request.setInterval(15000);
request.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
FusedLocationProviderClient client = LocationServices.getFusedLocationProviderClient(this);
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
final DatabaseReference ref = FirebaseDatabase.getInstance().getReference("connected/"+user.getUid());
int permission = ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION);
if (permission == PackageManager.PERMISSION_GRANTED) {
client.requestLocationUpdates(request, new LocationCallback() {
#Override
public void onLocationResult(LocationResult locationResult) {
android.location.Location location =
locationResult.getLastLocation();
String lat = Double.toString(location.getLatitude());
String lng = Double.toString(location.getLongitude());
Toast.makeText(getBaseContext(), "Lat "+lat, Toast.LENGTH_SHORT).show();
if (location != null) {
ref.setValue(locationObj);
}
enter code here}
}, null);
}
}

The fact your service isn't getting killed on Android 8 sounds like a matter of luck. Probably your Android 8 phone has enough resources and keeps the service alive, but it will be killed sooner or later.
To achieve your goal you need to run your service in foreground. Check out official documentation:
You should only use a foreground service when your app needs to perform a task that is noticeable by the user even when they're not directly interacting with the app. For this reason, foreground services must show a status bar notification with a priority of PRIORITY_LOW or higher, which helps ensure that the user is aware of what your app is doing. If the action is of low enough importance that you want to use a minimum-priority notification, you probably shouldn't be using a service; instead, consider using a scheduled job.
Every app that runs a service places an additional load on the system, consuming system resources. If an app tries to hide its services by using a low-priority notification, this can impair the performance of the app the user is actively interacting with. For this reason, if an app tries to run a service with a minimum-priority notification, the system calls out the app's behavior in the notification drawer's bottom section.

Try to register your broadcast receiver in your main activity along with the intent actions that you want your receiver to do like this
private void RegisteringBroadcastReciever()
{
broadcastReceiver = new XYZIntentReceiver();
var filter = new IntentFilter();
filter.AddAction("hearing.arc.intent.action.action1");
filter.AddAction("hearing.arc.intent.action.action2");
filter.AddAction("hearing.arc.intent.action.action3");
filter.AddAction("hearing.arc.intent.action.action4");
AppInstance.ApplicationContext.RegisterReceiver(broadcastReceiver, filter);
}
Even i had a similar kind of issue. But i had that issue on Oreo devices as well. But this fix has resolved my issue. And Android asks to unregister this receiver in onDestroy() method. But don't do that. It might kill the service again.
Hope this helps.

How to receive the driving start and stop activity with Android in an energy efficient manner which works even offline?

I would like to receive the Android location call backs for Driving Start and Stop. I have tried the Activity Detection API by Google but it doesn't seem to be reliable enough. As well as, I have looked into using Neura's API to detect the location events but it only works when the device is online which is not sufficient in my case.

You could use google's FenceApi in order to declare a driving fence.
Though this approach seems good, i've faced with the fact that this api didn't tell me sometimes when user starts/finishes driving, and sometimes it took a long time after i started driving that the api told me of that event.
a. include dependency to your app's build.gradle file :
compile 'com.google.android.gms:play-services-location:+'
compile 'com.google.android.gms:play-services-contextmanager:+'
b. Manifest definitions :
<uses-permission android:name="com.google.android.gms.permission.ACTIVITY_RECOGNITION" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme" >
<meta-data
android:name="com.google.android.awareness.API_KEY"
android:value="PUT_YOUR_AWARENESS_KEY_HERE" />
<activity android:name=".MainActivity" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
PUT_YOUR_AWARENESS_KEY_HERE : You need to generate a key here.
c. Your MainActivity class - explanations attached to the code :
public class MainActivity extends Activity {
private GoogleApiClient mGoogleApiClient;
private PendingIntent mPendingIntent;
private FenceReceiver mFenceReceiver;
// The intent action which will be fired when your fence is triggered.
private final String FENCE_RECEIVER_ACTION = BuildConfig.APPLICATION_ID + "FENCE_RECEIVER_ACTION";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mGoogleApiClient = new GoogleApiClient.Builder(this).addApi(Awareness.API).build();
mGoogleApiClient.connect();
// Set up the PendingIntent that will be fired when the fence is triggered.
mPendingIntent = PendingIntent.getBroadcast(this, 0, new Intent(FENCE_RECEIVER_ACTION), 0);
// The broadcast receiver that will receive intents when a fence is triggered.
mFenceReceiver = new FenceReceiver();
registerReceiver(mFenceReceiver, new IntentFilter(FENCE_RECEIVER_ACTION));
createFence(DetectedActivityFence.IN_VEHICLE, "InVehicleFence");
}
#Override
public void onDestroy() {
try {
unregisterReceiver(mFenceReceiver); //Don't forget to unregister the receiver
} catch (Exception e) {
e.printStackTrace();
}
super.onDestroy();
}
private void createFence(int detectedActivityFence, final String fenceKey) {
AwarenessFence fence = DetectedActivityFence.during(detectedActivityFence);
// Register the fence to receive callbacks.
Awareness.FenceApi.updateFences(
mGoogleApiClient, new FenceUpdateRequest.Builder().addFence(fenceKey, fence, mPendingIntent)
.build()).setResultCallback(new ResultCallback<Status>() {
#Override
public void onResult(#NonNull Status status) {
if (status.isSuccess()) {
Log.i(getClass().getSimpleName(), "Successfully registered.");
} else {
Log.e(getClass().getSimpleName(), "Could not be registered: " + status);
}
}
});
}
// Handle the callback on the Intent.
public class FenceReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
FenceState fenceState = FenceState.extract(intent);
switch (fenceState.getCurrentState()) {
case FenceState.TRUE:
Log.i(fenceState.getFenceKey(), "Driving");
break;
case FenceState.FALSE:
Log.i(fenceState.getFenceKey(), "Not driving");
break;
}
}
}
}

part-1 persistent foreGround android service that starts by UI, works at sleep mode too, also starts at phone restart

Status:--- I equally accept Karakuri's and Sharad Mhaske's answer, but since Sharad Mhaske answer after the start of bounty, the bounty should go to him.
Part-2 made: part-2 persistent foreGround android service that starts by UI, works at sleep mode too, also starts at phone restart
In stack overflow, only one answer may be accepted. I see both answers as acceptable but one has to be chosen (I chosed at random).
Viewers are invited to up/down vote answers/question to appreciate the effort!. I upvoted Karakuri's answer to compensate reputation.
Scenario:---
I want to make the user click a start/stop button and start/stop a service from UI activity. I have made the UI so dont care about that. But Just the logic of the Button click event.
Do not want the service to be bound to the UI activity. If activity closes, the service should keep running.
Want to make most effort that the service be persistent and does not stops in any case. Will give it most weight and run it as ForGroundSerice as it has a higher hierarchy of importance. (hope that's ok?)
Unless the stop button is clicked by my apps UI, do not want it to be stopped (or should restart itself) Even if android reclaim memory. I and the user of the phone, both are/will be aware of it. The service is most of importance. Even at sleep.
details= my app do some operations, sleep for user provided time (15 minuts usually), wakes and perform operations again. this never ends)
If I need AlarmManager, How to implement that? or any other way? Or just put the operations in a neverending while loop and sleep for 15 minuts at the end?
When the service is started (by clicked on start button). It should make an entry so that it auto starts if phone restarts.
QUESTION:---
Primary Question:
Just can't get an optimal strategy for the scenario... and also stuck on small bits of code, which one to use and how.
Gathered bits and pieces from stackoverflow.com questions, developer.android.com and some google results but cannot implement in integration.
Please read out the Requests Section.
Secondary Question:
The comments in my code are those small questions.
Research and Code:---
Strategy:
want this to happen every time the user opens the UI.
//Start Button:-----
//check if ForGroundService is running or not. if not running, make var/settings/etc "serviceStatus" as false
<-------(how and where to stare this and below stated boolean?)
//start ForGroundService
<-------(how?)
//make "SericeStatus" as true
//check if "ServiceStartOnBoot" is false
//Put ForGroundService to start on boot -------(to make it start when ever the phone reboots/restarts)
<-------(how?)
//make "ServiceStartOnBoot" as true
// the boolean can also be used to check the service status.
//Stop Button:------
//makes SericeStatus and ServiceStartOnBoot as false
//stops service and deletes the on boot entry/strategy
Activity UI class that starts/stops the service:
public class SettingsActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_settings);
//some button here to start / stop and their onClick Listners
Intent mySericeIntent = new Intent(this, TheService.class);
}
private void startMyForGroundService(){
startService(mySericeIntent);
}
private void stopMyForGroundSerice(){
stopService(mySericeIntent);
/////// is this a better approach?. stopService(new Intent(this, TheService.class));
/////// or making Intent mySericeIntent = new Intent(this, TheService.class);
/////// and making start and stop methods use the same?
/////// how to call stopSelf() here? or any where else? whats the best way?
}
}
The Service class:
public class TheService 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) {
startForeground(1, new Notification());
////// will do all my stuff here on in the method onStart() or onCreat()?
return START_STICKY; ///// which return is better to keep the service running untill explicitly killed. contrary to system kill.
///// http://developer.android.com/reference/android/app/Service.html#START_FLAG_REDELIVERY
//notes:-// if you implement onStartCommand() to schedule work to be done asynchronously or in another thread,
//then you may want to use START_FLAG_REDELIVERY to have the system re-deliver an Intent for you so that it does not get lost if your service is killed while processing it
}
#Override
public void onDestroy() {
stop();
}
public void stop(){
//if running
// stop
// make vars as false
// do some stopping stuff
stopForeground(true);
/////// how to call stopSelf() here? or any where else? whats the best way?
}
}
The Menifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="10"
android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:debuggable="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.myapp.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.myapp.SettingsActivity"
android:label="#string/title_activity_settings" >
</activity>
</application>
</manifest>
References:---
Android - implementing startForeground for a service? pointing answer 1, example code.
Trying to start a service on boot on Android
Android: Start Service on boot?
http://developer.android.com/guide/components/services.html
http://developer.android.com/reference/android/app/Service.html
http://developer.android.com/training/run-background-service/create-service.html not preffered by me.
http://developer.android.com/guide/components/processes-and-threads.html my starting point of research
Requests:---
I think this question is a normal practice for most people who are dealing with services.
In that vision, please only answer if you have experience in the scenario and can comprehensively explain the aspects and strategy with maximum sample code as a complete version so it would be a help to the community as well.
Vote up and down (with responsibility) to the answers as it matters to me who shared their views, time and experience and helped me and the community.

Que:Want to make most effort that the service be persistent and does not stops in any case. Will give it most weight and run it as ForGroundSerice as it has a higher hierarchy of importance. (hope that's ok?)
Answer:you need to start service with using START_STICKY Intent flag.
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// We want this service to continue running until it is explicitly
// stopped, so return sticky.
return START_STICKY;
}
Que:If I need AlarmManager, How to implement that? or any other way? Or just put the operations in a neverending while loop and sleep for 15 minuts at the end?
Answer:you need to register alarmmanager within service for the time after to some task.
//register alarm manager within service.
PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 0, new Intent("com.xxxxx.tq.TQServiceManager"), PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
alarmManager.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + 1000 , 30 * 1000 , pendingIntent);
//now have a broadcastreceiver to receive this intent.
class Alarmreceiver extends Broadcastreceiver
{
//u can to task in onreceive method of receiver.
}
//register this class in manifest for alarm receiver action.
Que:When the service is started (by clicked on start button). It should make an entry so that it auto starts if phone restarts.
Answer:use broadcast reciver to listen for onboot completed intent.
public class StartAtBootServiceReceiver extends BroadcastReceiver{
#Override
public void onReceive(Context context, Intent intent) {
try {
if( "android.intent.action.BOOT_COMPLETED".equals(intent.getAction())) {
ComponentName comp = new ComponentName(context.getPackageName(), LicensingService.class.getName());
ComponentName service = context.startService(new Intent().setComponent(comp));
if (null == service){
// something really wrong here
//Log.Write("Could not start service " + comp.toString(),Log._LogLevel.NORAML);
}
}
else {
//Log.Write("Received unexpected intent " + intent.toString(),Log._LogLevel.NORAML);
}
} catch (Exception e) {
//Log.Write("Unexpected error occured in Licensing Server:" + e.toString(),Log._LogLevel.NORAML);
}
}
}
//need to register this receiver for Action_BOOTCOMPLETED intent in manifest.xml file
Hope this helps you clear out things :)

If you start a service with startService(), it will keep running even when the Activity closes. It will only be stopped when you call stopService(), or if it ever calls stopSelf() (or if the system kills your process to reclaim memory).
To start the service on boot, make a BroadcastReceiver that just starts the service:
public class MyReceiver extends BroadcastReceiver {
public void onReceive(Context context, Intent intent) {
Intent service = new Intent(context, MyService.class);
context.startService(service);
}
}
Then add these to your manifest:
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<application ... >
<receiver android:name="MyReceiver"
android:enabled="false" >
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
</application>
Notice that the receiver is not enabled at first. When the user starts your service, use PackageManager to enable the receiver. When the user stops your service, use PackageManager to disable the receiver. In your Activity:
PackageManager pm = getPackageManager();
ComponentName receiver = new ComponentName(this, MyReceiver.class);
pm.setComponentEnabledSetting(receiver, PackageManager.COMPONENT_ENABLED_STATE_ENABLED, PackageManager.DONT_KILL_APP);
Use same method with PackageManager.COMPONENT_ENABLED_STATE_DISABLED to disable it.

I have made something like this myself but I learned a lot while developing it and discovered it is not completely necesary to have the service running all day draining your battery. what I made is the following:
Implement a Service that reacts to events. In my particular I wanted to automate my Wifi and mobile data connection. so i react to events like wifi connecting and disconnecting, screen turning on and off, etc. So this service executes what ever needs to be executed responding to this event and then stops, scheduling any further actions with the AlarmManager if so needed.
now, this events can by timers like you said yourself every 15 minutes it does something and sleeps, that sounds to me that you really dont want the service running 24/7 but just executing something every 15 minutes. that is perfectly achievable with the AlarmManager without keeping your service running forever.
I recommend implementing this service deriving from commonsware's WakefulIntentService.
This class already handles the wakeLock for you so that you can exceute code even if phone is asleep. it will simply wakeup execute and go back to sleep.
Now. About your question regarding the activity starting and stoping the service. you can implement in the button that it starts or cancels the AlarmManager alarm. Also you can use the sharedPreferences to store a simple boolean that tells you if it is enabled or not so the next time your service runs it can read the value and know if it should continue or stop.
If you implement it as a event-reactive service as i said, your button can even react to broadcast intents so that your activity doesn't even have to call the service directly just broadcast an intent and the service can pick it like other events. use a BroadcastReceiver for this.
I'll try to give examples but be wary that what you're asking is a lot of code to put it in one place...
BootReceiver:
public class BootReceiver extends BroadcastReceiver
{
private static final String TAG = BootReceiver.class.getSimpleName();
#Override
public void onReceive(final Context context, final Intent intent)
{
final Intent in = new Intent(context, ActionHandlerService.class);
in.setAction(Actions.BOOT_RECEIVER_ACTION); //start the service with a flag telling the event that triggered
Log.i(TAG, "Boot completed. Starting service.");
WakedIntentService.sendWakefulWork(context, in);
}
}
Service:
public class ActionHandlerService extends WakedIntentService
{
private enum Action
{
WIFI_PULSE_ON, WIFI_PULSE_OFF, DATA_PULSE_ON, DATA_PULSE_OFF, SCREEN_ON, SCREEN_OFF, WIFI_CONNECTS, WIFI_DISCONNECTS, WIFI_CONNECT_TIMEOUT, WIFI_RECONNECT_TIMEOUT, START_UP, BOOT_UP
}
public ActionHandlerService()
{
super(ActionHandlerService.class.getName());
}
#Override
public void run(final Intent intent)
{
mSettings = PreferenceManager.getDefaultSharedPreferences(this);
mSettingsContainer.enabled = mSettings.getBoolean(getString(R.string.EnabledParameter), false);
if (intent != null)
{
final String action = intent.getAction();
if (action != null)
{
Log.i(TAG, "received action: " + action);
if (action.compareTo(Constants.Actions.SOME_EVENT) == 0)
{
//Do what ever you want
}
else
{
Log.w(TAG, "Unexpected action received: " + action);
}
}
else
{
Log.w(TAG, "Received null action!");
}
}
else
{
Log.w(TAG, "Received null intent!");
}
}
}
And your Manifest could go something like this:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.yourcompany.yourapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="7"
android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<application
android:allowBackup="false"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.yourcompany.yourapp.activities.HomeActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name="com.yourcompany.yourapp.services.ActionHandlerService" />
<receiver android:name="com.yourcompany.yourapp.receivers.BootReceiver" >
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
<category android:name="android.intent.category.HOME" />
</intent-filter>
</receiver>
</application>
</manifest>

In Android how do you register to receive headset plug broadcasts?

I am working in Android 2.1, and I want to detect when the headset is plugged in/taken out. I'm pretty new to android.
I think the way to do it is using a Broadcast receiver. I sublcassed this, and I also put the following in my AndroidManifest.xml. But do you have to register the receiver somehwere else, like in the activity? I'm aware there are lots of threads on this, but I don't really understand what they're talking about. Also, what's the difference between registering in AndroidManifest.xml versus registering dynamically in your activity?
<receiver android:enabled="true" android:name="AudioJackReceiver" >
<intent-filter>
<action android:name="android.intent.action.HEADSET_PLUG" >
</action>
</intent-filter>
</receiver>
And this was the implementation of the class (plus imports)
public class AudioJackReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Log.w("DEBUG", "headset state received");
}
}
I was just trying to see if it works, but nothing shows up when I unplug/plug in the headset while running the application.
EDIT: the documentation doesn't say this, but is it possible that this one won't work if registered in the manifest? I was able to get it to respond when I registered the receiver in one of my applications (or do you have to do that anyway?)

Just complementing Greg`s answer, here is the code that you need divided in two parts
Register the Service in the first Activity (here its called MainActivity.java).
Switch over the result of the ACTION_HEADSET_PLUG action in the BroadCastReceiver.
Here it goes:
public class MainActivity extends Activity {
private static final String TAG = "MainActivity";
private MusicIntentReceiver myReceiver;
#Override protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myReceiver = new MusicIntentReceiver();
}
#Override public void onResume() {
IntentFilter filter = new IntentFilter(Intent.ACTION_HEADSET_PLUG);
registerReceiver(myReceiver, filter);
super.onResume();
}
private class MusicIntentReceiver extends BroadcastReceiver {
#Override public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Intent.ACTION_HEADSET_PLUG)) {
int state = intent.getIntExtra("state", -1);
switch (state) {
case 0:
Log.d(TAG, "Headset is unplugged");
break;
case 1:
Log.d(TAG, "Headset is plugged");
break;
default:
Log.d(TAG, "I have no idea what the headset state is");
}
}
}
}

Here are two sites that may help explain it in more detail:
http://www.grokkingandroid.com/android-tutorial-broadcastreceiver/
http://www.vogella.com/articles/AndroidBroadcastReceiver/article.html
You have to define your intent; otherwise it won't access the system function. The broadcast receiver; will alert your application of changes that you'd like to listen for.
Every receiver needs to be subclassed; it must include a onReceive(). To implement the onReceive() you'll need to create a method that will include two items: Context & Intent.
More then likely a service would be ideal; but you'll create a service and define your context through it. In the context; you'll define your intent.
An example:
context.startService
(new Intent(context, YourService.class));
Very basic example. However; your particular goal is to utilize a system-wide broadcast. You want your application to be notified of Intent.ACTION_HEADSET_PLUG.
How to subscribe through manifest:
<receiver
android:name="AudioJackReceiver"
android:enabled="true"
android:exported="true" >
<intent-filter>
<action android:name="android.intent.action.HEADSET_PLUG" />
</intent-filter>
</receiver>
Or you can simply define through your application; but. Your particular request; will require user permissions if you intend to detect Bluetooth MODIFY_AUDIO_SETTINGS.

You need to enable the broadcast receiver and set the exported attribute to true:
<receiver
android:name="AudioJackReceiver"
android:enabled="true"
android:exported="true" >
<intent-filter>
<action android:name="android.intent.action.HEADSET_PLUG" />
</intent-filter>
</receiver>