Android Beacon library dont work as foreground service

Question

I'm try to scan Eddystone TLM beacon using Android Beacon library foreground service or using JobScheduler-based scans. Android version 29. My code is android-beacon-library-reference. I'm add code for Eddystone TLM from documentation and beacon fouded and transmit data good. But when I uncomment code in BeaconReferenceApplication class for start foreground scan (or for JobScheduler-based scans) my beacon newer founded. Can anybody send me sample work example for scanning beacon in foreground? Оr explain me, what i need to do for make code working. Below application code:

public class BeaconMonitoringActivity extends Activity implements BeaconConsumer, RangeNotifier{
    protected static final String TAG = "BeaconMonitoringActivity";
    private BeaconManager mBeaconManager = BeaconManager.getInstanceForApplication(this);
    BackgroundPowerSaver backgroundPowerSaver;


    @RequiresApi(api = Build.VERSION_CODES.M)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_ranging);

        backgroundPowerSaver = new BackgroundPowerSaver(this);
        mBeaconManager.setBackgroundScanPeriod(5000L);
        mBeaconManager.setBackgroundBetweenScanPeriod(6000L);
    }



    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        switch (requestCode) {
            case 1: {
                if(grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    // {beacon code}
                }
            }
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
    }

    @Override
    public void onResume() {
        super.onResume();
        mBeaconManager = BeaconManager.getInstanceForApplication(this.getApplicationContext());
        // Detect the main Eddystone-UID frame:
        mBeaconManager.getBeaconParsers().add(new BeaconParser().
                setBeaconLayout(BeaconParser.EDDYSTONE_UID_LAYOUT));
        // Detect the telemetry Eddystone-TLM frame:
        mBeaconManager.getBeaconParsers().add(new BeaconParser().
                setBeaconLayout(BeaconParser.EDDYSTONE_TLM_LAYOUT));
        mBeaconManager.bind(this);
    }

    public void onBeaconServiceConnect() {
        Region region = new Region("all-beacons-region", null, null, null);
        try {
            mBeaconManager.startRangingBeaconsInRegion(region);
        } catch (RemoteException e) {
            e.printStackTrace();
        }
        mBeaconManager.addRangeNotifier(this);
    }

    @Override
    public void didRangeBeaconsInRegion(Collection<Beacon> beacons, Region region) {
        for (Beacon beacon: beacons) {
            if (beacon.getServiceUuid() == 0xfeaa && beacon.getBeaconTypeCode() == 0x00) {
                // This is a Eddystone-UID frame
                Identifier namespaceId = beacon.getId1();
                Identifier instanceId = beacon.getId2();
//                Log.d(TAG, "I see a beacon transmitting namespace id: "+namespaceId+
//                        " and instance id: "+instanceId+
//                        " approximately "+beacon.getDistance()+" meters away.");

                // Do we have telemetry data?
                int iDataSize = beacon.getExtraDataFields().size();
                if (beacon.getExtraDataFields().size() > 0) {
                    long telemetryVersion = beacon.getExtraDataFields().get(0);
                    long batteryMilliVolts = beacon.getExtraDataFields().get(1);
                    long telemetryTemperature = beacon.getExtraDataFields().get(2);
                    double tempValue= convertTemperature(telemetryTemperature);
                    long pduCount = beacon.getExtraDataFields().get(3);
                    long uptime = beacon.getExtraDataFields().get(4);

//                    Log.d(TAG, "The above beacon is sending telemetry version "+telemetryVersion+
//                            ", has been up for : "+uptime+" seconds"+
//                            ", has a battery level of "+batteryMilliVolts+" mV"+
//                            ", and has transmitted "+pduCount+" advertisements.");

                }
            }
        }
    }

    double convertTemperature(long source) {
        double temp;
        double temperature;
        long unsignedTemp = (source >> 8);
        if(unsignedTemp > 128) {
            temp = unsignedTemp - 256;
        }else{
            temp = unsignedTemp;
        }
        temperature = unsignedTemp + (source & 0xff) / 256.0;
        return temperature;
    }

    @Override
    public void onPause() {
        super.onPause();
        mBeaconManager.unbind(this);
    }

}

public class MonitoringActivity extends Activity  {
    protected static final String TAG = "MonitoringActivity";
    private static final int PERMISSION_REQUEST_FINE_LOCATION = 1;
    private static final int PERMISSION_REQUEST_BACKGROUND_LOCATION = 2;
    private static final int PERMISSION_REQUEST_COARSE_LOCATION = 3;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Log.d(TAG, "onCreate");
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_monitoring);
        verifyBluetooth();


        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (this.checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION)
                    == PackageManager.PERMISSION_GRANTED) {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
                    if (this.checkSelfPermission(Manifest.permission.ACCESS_BACKGROUND_LOCATION)
                            != PackageManager.PERMISSION_GRANTED) {
                        if (!this.shouldShowRequestPermissionRationale(Manifest.permission.ACCESS_BACKGROUND_LOCATION)) {
                            final AlertDialog.Builder builder = new AlertDialog.Builder(this);
                            builder.setTitle("This app needs background location access");
                            builder.setMessage("Please grant location access so this app can detect beacons in the background.");
                            builder.setPositiveButton(android.R.string.ok, null);
                            builder.setOnDismissListener(new DialogInterface.OnDismissListener() {

                                @TargetApi(23)
                                @Override
                                public void onDismiss(DialogInterface dialog) {
                                    requestPermissions(new String[]{Manifest.permission.ACCESS_BACKGROUND_LOCATION},
                                            PERMISSION_REQUEST_BACKGROUND_LOCATION);
                                }

                            });
                            builder.show();
                        }
                        else {
                            final AlertDialog.Builder builder = new AlertDialog.Builder(this);
                            builder.setTitle("Functionality limited");
                            builder.setMessage("Since background location access has not been granted, this app will not be able to discover beacons in the background.  Please go to Settings -> Applications -> Permissions and grant background location access to this app.");
                            builder.setPositiveButton(android.R.string.ok, null);
                            builder.setOnDismissListener(new DialogInterface.OnDismissListener() {

                                @Override
                                public void onDismiss(DialogInterface dialog) {
                                }

                            });
                            builder.show();
                        }
                    }
                }
            } else {
                if (!this.shouldShowRequestPermissionRationale(Manifest.permission.ACCESS_FINE_LOCATION)) {
                    requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION,
                                    Manifest.permission.ACCESS_BACKGROUND_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION},
                            PERMISSION_REQUEST_FINE_LOCATION);
                    requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
                            PERMISSION_REQUEST_COARSE_LOCATION);
                }
                else {
                    final AlertDialog.Builder builder = new AlertDialog.Builder(this);
                    builder.setTitle("Functionality limited");
                    builder.setMessage("Since location access has not been granted, this app will not be able to discover beacons.  Please go to Settings -> Applications -> Permissions and grant location access to this app.");
                    builder.setPositiveButton(android.R.string.ok, null);
                    builder.setOnDismissListener(new DialogInterface.OnDismissListener() {

                        @Override
                        public void onDismiss(DialogInterface dialog) {
                        }

                    });
                    builder.show();
                }

            }

        }

    }

    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           String permissions[], int[] grantResults) {
        switch (requestCode) {
            case PERMISSION_REQUEST_FINE_LOCATION: {
                if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    Log.d(TAG, "fine location permission granted");
                } else {
                    final AlertDialog.Builder builder = new AlertDialog.Builder(this);
                    builder.setTitle("Functionality limited");
                    builder.setMessage("Since location access has not been granted, this app will not be able to discover beacons.");
                    builder.setPositiveButton(android.R.string.ok, null);
                    builder.setOnDismissListener(new DialogInterface.OnDismissListener() {

                        @Override
                        public void onDismiss(DialogInterface dialog) {
                        }

                    });
                    builder.show();
                }
                return;
            }
            case PERMISSION_REQUEST_BACKGROUND_LOCATION: {
                if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    Log.d(TAG, "background location permission granted");
                } else {
                    final AlertDialog.Builder builder = new AlertDialog.Builder(this);
                    builder.setTitle("Functionality limited");
                    builder.setMessage("Since background location access has not been granted, this app will not be able to discover beacons when in the background.");
                    builder.setPositiveButton(android.R.string.ok, null);
                    builder.setOnDismissListener(new DialogInterface.OnDismissListener() {

                        @Override
                        public void onDismiss(DialogInterface dialog) {
                        }

                    });
                    builder.show();
                }
                return;
            }
        }
    }

    public void onRangingClicked(View view) {
//      Intent myIntent = new Intent(this, RangingActivity.class);
        Intent myIntent = new Intent(this, BeaconMonitoringActivity.class);
        this.startActivity(myIntent);
    }


    public void onEnableClicked(View view) {
        BeaconReferenceApplication application = ((BeaconReferenceApplication) this.getApplicationContext());
        if (BeaconManager.getInstanceForApplication(this).getMonitoredRegions().size() > 0) {
            application.disableMonitoring();
            ((Button)findViewById(R.id.enableButton)).setText("Re-Enable Monitoring");
        }
        else {
            ((Button)findViewById(R.id.enableButton)).setText("Disable Monitoring");
            application.enableMonitoring();
        }

    }

    @Override
    public void onResume() {
        super.onResume();
        BeaconReferenceApplication application = ((BeaconReferenceApplication) this.getApplicationContext());
       // application.setMonitoringActivity(this);
        updateLog(application.getLog());
    }

    @Override
    public void onPause() {
        super.onPause();
        ((BeaconReferenceApplication) this.getApplicationContext()).setMonitoringActivity(null);
    }

    private void verifyBluetooth() {

        try {
            if (!BeaconManager.getInstanceForApplication(this).checkAvailability()) {
                final AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setTitle("Bluetooth not enabled");
                builder.setMessage("Please enable bluetooth in settings and restart this application.");
                builder.setPositiveButton(android.R.string.ok, null);
                builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
                    @Override
                    public void onDismiss(DialogInterface dialog) {
                        //finish();
                        //System.exit(0);
                    }
                });
                builder.show();
            }
        }
        catch (RuntimeException e) {
            final AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setTitle("Bluetooth LE not available");
            builder.setMessage("Sorry, this device does not support Bluetooth LE.");
            builder.setPositiveButton(android.R.string.ok, null);
            builder.setOnDismissListener(new DialogInterface.OnDismissListener() {

                @Override
                public void onDismiss(DialogInterface dialog) {
                    //finish();
                    //System.exit(0);
                }

            });
            builder.show();

        }

    }

    public void updateLog(final String log) {
        runOnUiThread(new Runnable() {
            public void run() {
                EditText editText = (EditText)MonitoringActivity.this
                        .findViewById(R.id.monitoringText);
                editText.setText(log);
            }
        });
    }

}

public class BeaconReferenceApplication extends Application implements BootstrapNotifier {
    private static final String TAG = "BeaconReferenceApp";
    private RegionBootstrap regionBootstrap;
    private BackgroundPowerSaver backgroundPowerSaver;
    private BeaconMonitoringActivity monitoringActivity = null;
    private String cumulativeLog = "";

    public void onCreate() {
        super.onCreate();
        BeaconManager beaconManager = org.altbeacon.beacon.BeaconManager.getInstanceForApplication(this);

        // By default the AndroidBeaconLibrary will only find AltBeacons.  If you wish to make it
        // find a different type of beacon, you must specify the byte layout for that beacon's
        // advertisement with a line like below.  The example shows how to find a beacon with the
        // same byte layout as AltBeacon but with a beaconTypeCode of 0xaabb.  To find the proper
        // layout expression for other beacon types, do a web search for "setBeaconLayout"
        // including the quotes.
        //
        //beaconManager.getBeaconParsers().clear();
        //beaconManager.getBeaconParsers().add(new BeaconParser().
        //        setBeaconLayout("m:2-3=beac,i:4-19,i:20-21,i:22-23,p:24-24,d:25-25"));

        beaconManager.setDebug(true);


        // Uncomment the code below to use a foreground service to scan for beacons. This unlocks
        // the ability to continually scan for long periods of time in the background on Andorid 8+
        // in exchange for showing an icon at the top of the screen and a always-on notification to
        // communicate to users that your app is using resources in the background.
        //


        Notification.Builder builder = new Notification.Builder(this);
        builder.setSmallIcon(R.drawable.ic_launcher);
        builder.setContentTitle("Scanning for Beacons");
        Intent intent = new Intent(this, BeaconMonitoringActivity.class);
        PendingIntent pendingIntent = PendingIntent.getActivity(
                this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT
        );
        builder.setContentIntent(pendingIntent);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel("My Notification Channel ID",
                    "My Notification Name", NotificationManager.IMPORTANCE_DEFAULT);
            channel.setDescription("My Notification Channel Description");
            NotificationManager notificationManager = (NotificationManager) getSystemService(
                    Context.NOTIFICATION_SERVICE);
            notificationManager.createNotificationChannel(channel);
            builder.setChannelId(channel.getId());
        }
        beaconManager.enableForegroundServiceScanning(builder.build(), 456);

        beaconManager.setForegroundBetweenScanPeriod(0);
        beaconManager.setForegroundScanPeriod(60000);

        // For the above foreground scanning service to be useful, you need to disable
        // JobScheduler-based scans (used on Android 8+) and set a fast background scan
        // cycle that would otherwise be disallowed by the operating system.
        //
        beaconManager.setEnableScheduledScanJobs(false);
        beaconManager.setBackgroundBetweenScanPeriod(0);
        beaconManager.setBackgroundScanPeriod(11000);


        Log.d(TAG, "setting up background monitoring for beacons and power saving");
        // wake up the app when a beacon is seen
        Region region = new Region("backgroundRegion",
                null, null, null);
        regionBootstrap = new RegionBootstrap(this, region);

        // simply constructing this class and holding a reference to it in your custom Application
        // class will automatically cause the BeaconLibrary to save battery whenever the application
        // is not visible.  This reduces bluetooth power usage by about 60%
        backgroundPowerSaver = new BackgroundPowerSaver(this);

        // If you wish to test beacon detection in the Android Emulator, you can use code like this:
        // BeaconManager.setBeaconSimulator(new TimedBeaconSimulator() );
        // ((TimedBeaconSimulator) BeaconManager.getBeaconSimulator()).createTimedSimulatedBeacons();
    }

    public void disableMonitoring() {
        if (regionBootstrap != null) {
            regionBootstrap.disable();
            regionBootstrap = null;
        }
    }
    public void enableMonitoring() {
        Region region = new Region("backgroundRegion",
                null, null, null);
        regionBootstrap = new RegionBootstrap(this, region);
    }


    @Override
    public void didEnterRegion(Region arg0) {
        Log.d(TAG, "did enter region.");
        // Send a notification to the user whenever a Beacon
        // matching a Region (defined above) are first seen.
        Log.d(TAG, "Sending notification.");
        sendNotification();
        if (monitoringActivity != null) {
            // If the Monitoring Activity is visible, we log info about the beacons we have
            // seen on its display
            logToDisplay("I see a beacon again" );
        }
    }

    @Override
    public void didExitRegion(Region region) {
        logToDisplay("I no longer see a beacon.");
    }

    @Override
    public void didDetermineStateForRegion(int state, Region region) {
        logToDisplay("Current region state is: " + (state == 1 ? "INSIDE" : "OUTSIDE ("+state+")"));
    }

    private void sendNotification() {
        NotificationManager notificationManager =
                (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE);
        Notification.Builder builder;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel("Beacon Reference Notifications",
                    "Beacon Reference Notifications", NotificationManager.IMPORTANCE_HIGH);
            channel.enableLights(true);
            channel.enableVibration(true);
            channel.setLockscreenVisibility(Notification.VISIBILITY_PUBLIC);
            notificationManager.createNotificationChannel(channel);
            builder = new Notification.Builder(this, channel.getId());
        }
        else {
            builder = new Notification.Builder(this);
            builder.setPriority(Notification.PRIORITY_HIGH);
        }

        TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
        stackBuilder.addNextIntent(new Intent(this, BeaconMonitoringActivity.class));
        PendingIntent resultPendingIntent =
                stackBuilder.getPendingIntent(
                        0,
                        PendingIntent.FLAG_UPDATE_CURRENT
                );
        builder.setSmallIcon(R.drawable.ic_launcher);
        builder.setContentTitle("I detect a beacon");
        builder.setContentText("Tap here to see details in the reference app");
        builder.setContentIntent(resultPendingIntent);
        notificationManager.notify(1, builder.build());
    }

    public void setMonitoringActivity(BeaconMonitoringActivity activity) {
        this.monitoringActivity = activity;
    }

    private void logToDisplay(String line) {
        cumulativeLog += (line + "\n");
        if (this.monitoringActivity != null) {
            //this.monitoringActivity.updateLog(cumulativeLog);
        }
    }

    public String getLog() {
        return cumulativeLog;
    }

}

Thanks

Answer 1

A few issues:

1. BackgroundPower saver should be set up once. Right now it is set up in the BeaconMonitoringActivity and BeaconScannerApplication. I suggest you remove it from BeaconMonitoringActivity.

2. Similarly, the Eddystone parser should be set up once. I suggest you move it from the onResume method of BeaconMonitoringActivity to BeaconScannerApplication right where the comment says // By default the AndroidBeaconLibrary will only find AltBeacons. If you wish to make it find a different type of beacon, you must specify the byte layout for that beacon's...

3. The scan period configured (beaconManager.setForegroundScanPeriod(60000);) will case the library to scan for beacons for a full 60 seconds before reporting them to your application. What you perceive as a failure to detect may just be that it is taking 60 seconds to get each callback. Try setting this to a lower number like 1100ms.