ForegroundService.java

public class ForegroundService extends Service {

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        String input = intent.getStringExtra("inputExtra");
        createNotificationChannel();
        
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, YourActivity.class), 0);
        
        Notification notification = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setContentTitle("Foreground Service")
                .setContentText(input)
                .setSmallIcon(R.drawable.ic_stat_name)
                .setContentIntent(pendingIntent)
                .build();
        
        startForeground(1, notification);
        
        // here is the code you wanna run in background
        
        return START_NOT_STICKY;
    }

    private void createNotificationChannel() {
        NotificationChannel serviceChannel = new NotificationChannel(
                CHANNEL_ID,
                "Foreground Service Channel",
                NotificationManager.IMPORTANCE_DEFAULT);
      
        getSystemService(NotificationManager.class).createNotificationChannel(serviceChannel);
    }
}