Unable to get UUID of a iBeacon on pre-Lollipop devices

Question

I'm unable to get UUID of a iBeacon on pre-Lollipop devices, but below my code is working in Marshmallow Nexus 5x.

I dont want to use any library like AltBeacon or related.

BluetoothManager bm = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
BluetoothAdapter mBluetoothAdapter = bm.getAdapter();
if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()) {
    //Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
    //startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
} else {
    BluetoothLeScanner scanner = mBluetoothAdapter.getBluetoothLeScanner();
    // scan for devices
    scanner.startScan(new ScanCallback() {
        @Override
        public void onScanResult(int callbackType, ScanResult result) {
            // get the discovered device as you wish
            // this will trigger each time a new device is found
            BluetoothDevice device = result.getDevice();
            if (device.getType() == BluetoothDevice.DEVICE_TYPE_LE) { //int the device type DEVICE_TYPE_CLASSIC, DEVICE_TYPE_LE DEVICE_TYPE_DUAL. DEVICE_TYPE_UNKNOWN if it's not available
                if (device.fetchUuidsWithSdp()) {
                    System.out.println(device.getName());
                    List<ParcelUuid> uuids = result.getScanRecord().getServiceUuids();
                    System.out.println(uuids);
                    System.out.println(getMajor(result.getScanRecord().getBytes()));
                    System.out.println(getMinor(result.getScanRecord().getBytes()));
                } else {
                    System.out.println("failed");
                }
            }
        }
    });
}

score 4 · Accepted Answer · edited Feb 22 '16 at 11:50

BluetoothManager bm = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
           BluetoothAdapter mBluetoothAdapter = bm.getAdapter();
           if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()) {
               //Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
               //startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
           } else {

               if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                   BluetoothLeScanner scanner = mBluetoothAdapter.getBluetoothLeScanner();
                   // scan for devices
                   scanner.startScan(new ScanCallback() {
                       @TargetApi(Build.VERSION_CODES.LOLLIPOP)
                       @Override
                       public void onScanResult(int callbackType, ScanResult result) {
                           // get the discovered device as you wish
                           // this will trigger each time a new device is found
                           BluetoothDevice device = result.getDevice();
                           if (device.getType() == BluetoothDevice.DEVICE_TYPE_LE)//int    the device type DEVICE_TYPE_CLASSIC, DEVICE_TYPE_LE DEVICE_TYPE_DUAL. DEVICE_TYPE_UNKNOWN if it's not available
                           {
                               if (device.fetchUuidsWithSdp()) {
                                   System.out.println(device.getName());
                                   List<ParcelUuid> uuids = result.getScanRecord().getServiceUuids();
                                   System.out.println(uuids);
                                   System.out.println(getMajor(result.getScanRecord().getBytes()));
                                   System.out.println(getMinor(result.getScanRecord().getBytes()));

                               } else {
                                   System.out.println("failed");
                               }
                           }
                       }
                   });
               } else {
                   // targetting kitkat or bellow
                   mBluetoothAdapter.startLeScan(new BluetoothAdapter.LeScanCallback() {
                       @Override
                       public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) {
                           // get the discovered device as you wish\

                       }
                   });
               }
           }

score 4 · Answer 2 · answered Feb 23 '16 at 04:07

public void onLeScan(BluetoothDevice device, int rssi, final byte[] scanRecord) {
       int startByte = 2;
       boolean patternFound = false;
       while (startByte <= 5) {
           if (    ((int) scanRecord[startByte + 2] & 0xff) == 0x02 && //Identifies an iBeacon
                   ((int) scanRecord[startByte + 3] & 0xff) == 0x15) { //Identifies correct data length
               patternFound = true;
               break;
           }
           startByte++;
       }

       if (patternFound) {
           //Convert to hex String
           byte[] uuidBytes = new byte[16];
           System.arraycopy(scanRecord, startByte+4, uuidBytes, 0, 16);
           String hexString = bytesToHex(uuidBytes);

           //Here is your UUID
           String uuid =  hexString.substring(0,8) + "-" +
                   hexString.substring(8,12) + "-" +
                   hexString.substring(12,16) + "-" +
                   hexString.substring(16,20) + "-" +
                   hexString.substring(20,32);

           //Here is your Major value
           int major = (scanRecord[startByte+20] & 0xff) * 0x100 + (scanRecord[startByte+21] & 0xff);

           //Here is your Minor value
           int minor = (scanRecord[startByte+22] & 0xff) * 0x100 + (scanRecord[startByte+23] & 0xff);

           System.out.println(String.format("%s\n%s\n%s",uuid,major,minor));
           textView.setText(String.format("%s\n%s\n%s", uuid,major,minor));
       }
   }

   /**
    * bytesToHex method
    * Found on the internet
    * http://stackoverflow.com/a/9855338
    */
   static final char[] hexArray = "0123456789ABCDEF".toCharArray();
   private static String bytesToHex(byte[] bytes) {
       char[] hexChars = new char[bytes.length * 2];
       for ( int j = 0; j < bytes.length; j++ ) {
           int v = bytes[j] & 0xFF;
           hexChars[j * 2] = hexArray[v >>> 4];
           hexChars[j * 2 + 1] = hexArray[v & 0x0F];
       }
       return new String(hexChars);
   }

Call the method like this and Enjoy :) onLeScan(device,result.getRssi(),result.getScanRecord().getBytes());

Unable to get UUID of a iBeacon on pre-Lollipop devices

2 Answers2