01_Bluetooth.java

BluetoothManager manager = 
    (BluetoothManager) activity.getSystemService(Context.BLUETOOTH_SERVICE);
BluetoothAdapter adapter = manager.getAdapter();

02_Scanning.java

bluetoothAdapter.startLeScan(callback);

// BluetoothAdapter.LeScanCallback 
@Override
public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) {
   // process scan results
}

03_Filter.java

bluetoothAdapter.startLeScan(serviceUUIDs, callback);

04_Stop

bluetoothAdapter.stopLeScan(callback);