android BluetoothDevice.getName() return null

Question

On sometime, BluetoothDevice.getName() return null. How can i fix it? remoteDeviceName maybe null in following code. And i need distinguish my device and other devices by remoteDeviceName.

BluetoothAdapter.getDefaultAdapter().startLeScan(new LeScanCallback() {
            @Override
            public void onLeScan(final BluetoothDevice device, final int rssi,
                    byte[] scanRecord) {
                    String remoteDeviceName = device.getName();
                  Log.d("Scanning", "scan device " + remoteDeviceName);
            });

Answer 1

Finally, i found out the solution:

1.For device connected:

Read device name from gatt characteristic org.bluetooth.characteristic.gap.device_name of service org.bluetooth.service.generic_access.

2.For device no connected:

    /**
     * Get device name from ble advertised data
     */
    private LeScanCallback mScanCb = new LeScanCallback() {
        @Override
        public void onLeScan(final BluetoothDevice device, final int rssi,
            byte[] scanRecord) {
            final BleAdvertisedData badata = BleUtil.parseAdertisedData(scanRecord);
            String deviceName = device.getName();
            if( deviceName == null ){
                deviceName = badata.getName();
            }
    }


////////////////////// Helper Classes: BleUtil and BleAdvertisedData ///////////////
    final public class BleUtil {        
        private final static String TAG=BleUtil.class.getSimpleName();
        public static BleAdvertisedData parseAdertisedData(byte[] advertisedData) {      
            List<UUID> uuids = new ArrayList<UUID>();
            String name = null;
            if( advertisedData == null ){
                return new BleAdvertisedData(uuids, name);
            }

            ByteBuffer buffer = ByteBuffer.wrap(advertisedData).order(ByteOrder.LITTLE_ENDIAN);
            while (buffer.remaining() > 2) {
                byte length = buffer.get();
                if (length == 0) break;

                byte type = buffer.get();
                switch (type) {
                    case 0x02: // Partial list of 16-bit UUIDs
                    case 0x03: // Complete list of 16-bit UUIDs
                        while (length >= 2) {
                            uuids.add(UUID.fromString(String.format(
                                    "%08x-0000-1000-8000-00805f9b34fb", buffer.getShort())));
                            length -= 2;
                        }
                        break;
                    case 0x06: // Partial list of 128-bit UUIDs
                    case 0x07: // Complete list of 128-bit UUIDs
                        while (length >= 16) {
                            long lsb = buffer.getLong();
                            long msb = buffer.getLong();
                            uuids.add(new UUID(msb, lsb));
                            length -= 16;
                         }
                        break;
                    case 0x09:
                        byte[] nameBytes = new byte[length-1];
                        buffer.get(nameBytes);
                        try {
                            name = new String(nameBytes, "utf-8");
                        } catch (UnsupportedEncodingException e) {
                            e.printStackTrace();
                        }
                        break;
                    default:
                        buffer.position(buffer.position() + length - 1);
                        break;
                    }
                }
            return new BleAdvertisedData(uuids, name);
        }
    }


    public class BleAdvertisedData {
        private List<UUID> mUuids;
        private String mName;
        public BleAdvertisedData(List<UUID> uuids, String name){
            mUuids = uuids;
            mName = name;
        }

        public List<UUID> getUuids(){
            return mUuids;
        }

        public String getName(){
            return mName;
        }
    }

Answer 2

BluetoothDevice.getName() may return null if the name could not be determined. This could be due to any number of factors. Regardless, the name is the friendly name of the device, and shouldn't be used to distinguish it from other devices. Instead, use the hardware address through getAddress().