using altbeacon library on android 8(oreo), background beacon scan not working

Question

My app using Altbeacon library for beacon scanning.

my code working well to api level 24(android 7) but doesn't not working on oreo(8.0.0)

at first, my gradle setting compileSdkVersion and targetSdkVersion is 26, i thought it was because of this.

so, i reference this**https://developer.android.com/about/versions/oreo/background.html#services**, fix my gradle setting(compileSdkVersion 25, targetSdkVersion 25).

and install this app on device (apilevel 24, 26) on 24 level device working well, but 26 is not.

that's my code.

In Activity.onCreate

    Intent intent = new Intent(this, BeaconService.class);
    startService(intent);

in BeaconService(Altbeacon Library)

@Override
public void onBeaconServiceConnect()
{
    final Handler h = new Handler(getApplicationContext().getMainLooper());
    Beacon[] tempBeacon = new Beacon[2];

    bm.addRangeNotifier(new RangeNotifier() {
        @Override
        public void didRangeBeaconsInRegion(final Collection beacons, final Region region) {

            if (beacons.size() > 0) {

                //call method this context

            }
            Log.d("beacon", "detect");
        }
    });

    try
    {
            bm.startRangingBeaconsInRegion(new Region("test", Identifier.parse("A1200001-EABC-9876-D001-E00000000001"), Identifier.parse("32001"), null));
    } catch (RemoteException e) {
    }
}

EDIT: beacon is detected, but it takes a very long time.

And i saw log below

03-15 18:25:02.639 2419-2419/app.eco.inulibrary D/ScanJobScheduler: Scheduling ScanJob (job:208352940/app.eco.inulibrary/org.altbeacon.beacon.service.ScanJob) to run every 310000 millis 03-15 18:25:02.917 2419-2419/app.eco.inulibrary D/ScanJobScheduler: Scheduling ScanJob (job:208352940/app.eco.inulibrary/org.altbeacon.beacon.service.ScanJob) to run every 300000 millis 03-15 18:36:00.176 2419-2419/app.eco.inulibrary I/ScanJob: Running periodic scan job: instance is org.altbeacon.beacon.service.ScanJob@a6ca148 03-15 18:36:01.751 2419-3951/app.eco.inulibrary D/RangeState: adding id1: a1200001-eabc-9876-d001-e00000000001 id2: 32001 id3: 2001 to existing range for: org.altbeacon.beacon.service.RangedBeacon@bf2cb74 03-15 18:36:01.968 2419-2419/app.eco.inulibrary D/Callback: attempting callback via local broadcast intent: org.altbeacon.beacon.range_notification

how to solve this problem?

Answer 1

Android O introduces new limits on Background services. Services like the BeaconService shown in the code will be killed by the operating system shortly after the app switches to background mode.

The AndroidBeaconLibrary has been updated to account for this by using the Android job scheduler to handle beacon scanning on Android 8+. But for this to work, you must use the BeaconManager or RegionBootsrap classes to start scanning, rather than starting the BeaconService directly with an Intent. This way, the library will know to use the job scheduler on Android 8+ and the BeaconService on earlier versions.

Further, you will need to move your code that starts scanning and initializes ranging out of an Activity and into a custom android.app.Application class. This is because Android 8 will kill your Activity along with the app when it is in the background, and you will need to have your ranging set up in an Android component that is created automatically when the app is re-launched in the background for periodic scanning.

I recommend you rework your setup be as described in Starting an App in the Background in the sample code here. That sample only sets up monitoring, but you can start ranging in the didDetermineStateForRegion callback shown.

Finally, make sure you have library version 2.13+ which has full support for changes in Android 8.1.

To understand more about how background beacon detection has changed in Android 8, see my blog post here.