oreo need a foreground notification (it can be hidden by user)

app/src/main/java/eu/droogers/smsmatrix/MatrixService.java

@@ -1,14 +1,22 @@
 package eu.droogers.smsmatrix;
 
+import android.app.Notification;
+import android.app.NotificationChannel;
+import android.app.NotificationManager;
 import android.app.Service;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
+import android.graphics.Color;
+import android.os.Build;
 import android.os.IBinder;
 import android.util.Log;
 import android.widget.Toast;
 
+import androidx.annotation.RequiresApi;
+import androidx.core.app.NotificationCompat;
+
 /**
  * Created by gerben on 7-10-17.
  */
@@ -24,6 +32,7 @@ public class MatrixService extends Service {
     private String syncDelay;
     private String syncTimeout;
     private MMSMonitor mms;
+    private String mChannelId = "";
 
     @Override
     public void onCreate() {
@@ -32,6 +41,21 @@ public class MatrixService extends Service {
 
     @Override
     public int onStartCommand(Intent intent, int flags, int startId) {
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
+            if (mChannelId.isEmpty()) {
+                mChannelId = createNotificationChannel("sync", "Sync Service");
+            }
+            NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, mChannelId);
+            Notification notification = notificationBuilder.setOngoing(true)
+                    .setSmallIcon(R.mipmap.ic_launcher)
+                    .setContentText(getApplicationInfo().loadLabel(getPackageManager()))
+                    .setPriority(NotificationCompat.PRIORITY_MIN)
+                    .setCategory(Notification.CATEGORY_SERVICE)
+                    .build();
+            startForeground(1, notification);
+        }
+
         SharedPreferences sp = getSharedPreferences("settings", Context.MODE_PRIVATE);
         botUsername = sp.getString("botUsername", "");
         botPassword = sp.getString("botPassword", "");
@@ -76,6 +100,17 @@ public class MatrixService extends Service {
 
     }
 
+    @RequiresApi(api = Build.VERSION_CODES.O)
+    private String createNotificationChannel(String channelId, String channelName){
+        NotificationChannel chan = new NotificationChannel(channelId,
+                channelName, NotificationManager.IMPORTANCE_NONE);
+        chan.setLightColor(Color.BLUE);
+        chan.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);
+        NotificationManager service = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
+        service.createNotificationChannel(chan);
+        return channelId;
+    }
+
     @Override
     public void onDestroy() {
         mx.destroy();

app/src/main/java/eu/droogers/smsmatrix/ReceiverListener.java

@@ -6,7 +6,9 @@ import android.content.Intent;
 import android.os.Bundle;
 import android.telephony.SmsMessage;
 import android.telephony.TelephonyManager;
-import android.util.Log;
+
+import androidx.core.content.ContextCompat;
+
 import java.util.HashMap;
 import java.util.Map;
 
@@ -26,7 +28,7 @@ public class ReceiverListener extends BroadcastReceiver {
         }
         else if (intent.getAction().equals("android.intent.action.BOOT_COMPLETED")) {
             Intent intentServ = new Intent(context, MatrixService.class);
-            context.startService(intent);
+            ContextCompat.startForegroundService(context, intentServ);
         }
     }