Develop Reference

how to start a background service in oreo?

by default all the service starts in Background using startService() before oreo version , but in oreo there is some restriction to start a service in background, Can I start a background service in oreo using startService() ?

You can use startService() as long as your app is in foreground , if your app goes background and you call startService() you will get IllegalStateException
Alternatively you can use startForeground() to start a service
From documentation
While an app is in the foreground, it can create and run both foreground and background services freely. When an app goes into the background, it has a window of several minutes in which it is still allowed to create and use services. At the end of that window, the app is considered to be idle. At this time, the system stops the app's background services, just as if the app had called the services' Service.stopSelf() methods
check Documentation for more info

You can run a service in background service. But if you want to run a background operations regardless if the app is in the foreground is not and you're not binding the service to a server then I'd use a foreground service. So in your main call this:
if(Build.VERSION.SDK_INT >25){
startForegroundService(new Intent(this, Service.class));
}else{
startService(new Intent(this, Service.class));
}
Then when you're in your service you have to document that the foreground service is running. You can call this method to handle documenting it in the foreground (it is a little clumsy):
private void startRunningInForeground() {
//if more than or equal to 26
if (Build.VERSION.SDK_INT >= 26) {
//if more than 26
if(Build.VERSION.SDK_INT > 26){
String CHANNEL_ONE_ID = "Package.Service";
String CHANNEL_ONE_NAME = "Screen service";
NotificationChannel notificationChannel = null;
notificationChannel = new NotificationChannel(CHANNEL_ONE_ID,
CHANNEL_ONE_NAME, NotificationManager.IMPORTANCE_MIN);
notificationChannel.enableLights(true);
notificationChannel.setLightColor(Color.RED);
notificationChannel.setShowBadge(true);
notificationChannel.setLockscreenVisibility(Notification.VISIBILITY_PUBLIC);
NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
if (manager != null) {
manager.createNotificationChannel(notificationChannel);
}
Bitmap icon = BitmapFactory.decodeResource(getResources(), R.drawable.background_running);
Notification notification = new Notification.Builder(getApplicationContext())
.setChannelId(CHANNEL_ONE_ID)
.setContentTitle("Recording data")
.setContentText("App is running background operations")
.setSmallIcon(R.drawable.background_running)
.setLargeIcon(icon)
.build();
Intent notificationIntent = new Intent(getApplicationContext(), MainActivity.class);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
notification.contentIntent = PendingIntent.getActivity(getApplicationContext(), 0, notificationIntent, 0);
startForeground(101, notification);
}
//if version 26
else{
startForeground(101, updateNotification());
}
}
//if less than version 26
else{
Notification notification = new NotificationCompat.Builder(this)
.setContentTitle("App")
.setContentText("App is running background operations")
.setSmallIcon(R.drawable.background_running)
.setOngoing(true).build();
startForeground(101, notification);
}
}
private Notification updateNotification() {
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0,
new Intent(this, MainActivity.class), 0);
return new NotificationCompat.Builder(this)
.setContentTitle("Activity log")
.setTicker("Ticker")
.setContentText("app is running background operations")
.setSmallIcon(R.drawable.background_running)
.setContentIntent(pendingIntent)
.setOngoing(true).build();
}
you'll also have to document the presence of a service in the manifest (in between the activity tags):
<service android:name = ".Service"/>
like and comment if you need help making a notification icon

object not locked by thread before notify() in Foreground Service Notification

From android O you cant create simple background service, it has to be foreground, so I followed a tutorial and built one, but, I got this error:
Unable to start service ...SMSService#302fa17 with Intent
{ cmp=...SMSService (has extras) }: java.lang.IllegalMonitorStateException:
object not locked by thread before notify()
I saw some other topics on this, but those are all for old Notifications
Here is my code:
Intent notificationIntent = new Intent(this, MainActivity.class);
PendingIntent mPendingIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);
Notification mNotification = new NotificationCompat.Builder(this, CHANNEL_ID)
.setContentTitle("Content Title")
.setContentText("Content Text")
.setSmallIcon(R.drawable.ic_check)
.setContentIntent(mPendingIntent)
.build();
startForeground(1, mNotification);
mNotification.notify();

When you try to call notify on specific object it wakes up a single thread that is waiting on this object's monitor.
Since you are not locking any thread, you don't have to use notify(). Remove mNotification.notify();.
As for displaying notification startForeground(1, notification); is enough

android: how to call activity by clicking foreground service notification

I start a foreground service which shows a notification. If my activity is hidden I want it start by clicking on the notification.
A function called in onStartCommand does this:
startForeground(noti_id, mNoti);
The notification appears and works but it doesn't reactivate my MainActivity:
notiIntent = new Intent(this, MainGate.class);
notiPendingIntent = PendingIntent.getActivity(this, 0, notiIntent, PendingIntent.FLAG_UPDATE_CURRENT);
MainGate.class is the activity which starts the foreground service. It should appear when I click on the notification.
EDIT:
Actually, it worked when the notification was built in the man activity (MainGate.class). And it worked when notification was built in the service not being foreground service. Now I had to implement the foreground service and it stopped working.

try this solution
Intent notificationIntent = new Intent(this, MainGate.class);
PendingIntent pendingIntent=PendingIntent.getActivity(this, 0,
notificationIntent, Intent.FLAG_ACTIVITY_NEW_TASK);
Notification notification=new NotificationCompat.Builder(this)
.setSmallIcon(R.drawable.ic_launcher)
.setContentText(getString(R.string.isRecording))
.setContentIntent(pendingIntent).build();
startForeground(NOTIFICATION_ID, notification);

Tap Event for a Service Foreground Notification Android

I have a service with a foreground notification.
How can launch an activity when user tap on the foreground Notification?
I have tried with:
// CREATE NOTIFICATION FOREGROUND
Intent notificationIntent = new Intent(getApplicationContext(), HomeActivity.class);
PendingIntent contentIntent = PendingIntent.getActivity(getApplicationContext(), 0, notificationIntent, 0);
Notification notification = new NotificationCompat.Builder(getApplicationContext())
.setContentTitle("Title")
.setTicker("Test service")
.setContentIntent(contentIntent)
.setContentText("text...").build();
startForeground(1, notification);
//======================================================================================
i need to start HomeActivity when user tap foreground notification.

Notification does not work properly on some devices

In my app I use a service for background work(send data to server) when my app is in the background.So I create a notification which tells to the user that app is running in the background.I want when the user taps on the notification my app to come to the foreground so I use an Intent like this that android use to launch my app
NotificationCompat.Builder mBuilder =
new NotificationCompat.Builder(this)
.setSmallIcon(R.drawable.final_driver_notification_icon)
.setContentTitle("...")
.setContentText("...");
final Intent notintent = new Intent(getApplicationContext(),EntryScreen.class);
notintent.setAction(Intent.ACTION_MAIN);
notintent.addCategory(Intent.CATEGORY_LAUNCHER);
PendingIntent pendint = PendingIntent.getActivity(this, 0, notintent, 0);
mBuilder.setContentIntent(pendint);
int notID = 001;
startForeground(notID, mBuilder.build());
In the emulator and some physical devices works perfect.But in some other it launches the app from the start(It puts Entry screen in the top).
Any idea why is this happening?

You should start your service with startForeground(). this is the way to start a service in foreground and report by a notification. Android - implementing startForeground for a service?
or try something like this:
public void initForeground() {
Intent intentForeground = new Intent(this, Activity.class);
intentForeground.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intentForeground,0);
pendingIntent.cancel();
pendingIntent = PendingIntent.getActivity(this, 0, intentForeground,0);
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getApplicationContext())
.setSmallIcon(R.drawable.icon)
.setContentIntent(pendingIntent)
.setContentTitle(getString(R.string.app_name))
.setContentText(getString(R.string.something))
.setTicker(getString(R.string.something))
.setAutoCancel(false);
Notification notification = mBuilder.build();
startForeground(myID, notification);
}
Hope it helps you!