如何使用 SPP 连接多个蓝牙设备？

Question

I am creating an Android APP which could connect the two BT device and do the communication over SPP. To create such application I am following the simple logic.

I got the two mac addressed of the BT Device, so in a for loop I am connecting the BT Devices as below:

private void connect() {
    BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    String[] strDevice = deviceAddress.split(",");
    BluetoothDevice device = null;
    String currentConnection;
    String deviceName = "";
    try {
        disconnect();
        Thread.sleep(500);

        for (String item: strDevice) {
            Log.d(TAG,"item is: " + item + " size is: " + strDevice.length);
            currentConnection = item;
            device = bluetoothAdapter.getRemoteDevice(item);
            deviceName = device.getName() != null ? device.getName() : device.getAddress();
            status("connecting..." + item);
            connected = Connected.Pending;
            socket = new SerialSocket();
            service.connect(this, "Connected to " + deviceName);
            socket.connect(getContext(), service, device);

            Thread.sleep(500);
        }


    } catch (Exception e) {
        onSerialConnectError(e);
    }
}

Using above code, I am able to connect the two BT devices. But the problem is when I close the activity I disconnect them but at that time only one device disconnects. I am calling the disconnect on "OnDestroy" of the fragment:

@Override
public void onDestroy() {
    if (connected != Connected.False) {
        disconnect();
    }
    getActivity().stopService(new Intent(getActivity(), SerialService.class));
    super.onDestroy();
}

void disconnect() {
    listener = null; // ignore remaining data and errors
    connected = false; // run loop will reset connected
    if(socket != null) {
        try {
            socket.close();
        } catch (Exception ignored) {
        }
        socket = null;
    }
    try {
        context.unregisterReceiver(disconnectBroadcastReceiver);
    } catch (Exception ignored) {
    }
}

I need a help to find out why on disconnect, only one device is disconnecting? Do I need to close two sockets because during connection it opened 2 sockets for two devices? If yes, how can I close two sockets?

Thanks in Advance

Answer 1

Here's the solution:

The issue was described above that on socket disconnect only one of the BT device was disconnecting. To resolve the situation, what I did is, I saved the socket in a concurrent list whenever it's created and connected.

So when the disconnect happens, I disconnected all the sockets from the list which are connected. This way it disconnects all the BT device.

Thanks.