Kontakt beacon uniqueId sometimes null

Question

Recently I started playing with a few Kontakt beacons and my Android phone (LG L30).

I added a default region to detect all beacons:

private static final Region ALL_BEACONS_REGION = Region.EVERYWHERE;

And I initialized a new monitoringListener. The relevant code:

    @Override
    public void onBeaconsUpdated(Region region, List<BeaconDevice> list) {
       List<BeaconDevice> beacons = new ArrayList<BeaconDevice>();
       Iterator i = list.iterator();
       while (i.hasNext()){
           BeaconDevice beacon = (BeaconDevice)i.next();
           if(beacon.getUniqueId() != null) {
               beacons.add(beacon);
           }
        }    
  }

While debugging I noticed, that sometimes the uniqueId is null. That's why I am checking if it is null, but I still find it very strange. Is that common or is there a mistake in my code? And how can I uniquely identify a beacon if the name is null?

Answer 1

Hmm to check why getUniqueId() return NULL, we must see how you set this value.

An object you can identify uniquely by using his hashCode(). Override this method in the object to generate something uniquely.
see: overriding equals and hashCode in Java

Or if you want only prevent multiple-entries in the list, you could us a Set, which not add duplicates (compared to the your ArrayList). see: Java - Set