通过蓝牙将数据从Android（客户端）发送到Python（服务器）

Question

I am trying to send data from Android Client (Nexus 4) to Python Server (Linux Machine) over Bluetooth using Python-bluez. Whenever the client writes some bytes to the OutputStream it throws an IO exception "Broken Pipe". The server also seems that it does not accept any connections although the Android client did not throw any exceptions after "socket_name.connect()"

Android Client:

public class MainActivity extends Activity {
    private BluetoothSocket ClientSocket;
    private BluetoothDevice Client;
    private ConnectedThread Writer;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    public BluetoothAdapter mblue;
    public void connect(View sender)
    {
        mblue = BluetoothAdapter.getDefaultAdapter();
        int REQUEST_ENABLE_BT = 1;
        final TextView er = (TextView)findViewById(R.id.Error);
        if(mblue == null)
             er.setText("No Bluetooth!");
        else if (mblue.isEnabled()) {
            er.setText(mblue.getAddress() + " " + mblue.getName());
        }
        else{
            Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
        }
    }

    public void disov(View sender)
    {

        final TextView er = (TextView)findViewById(R.id.Error);
        boolean tr = mblue.startDiscovery();
        if(tr == true)
        {
            er.setText("Disovering !!");
        }
        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        registerReceiver(mReceiver, filter);

    }
    public void start(View sender)
    {
        final TextView er = (TextView)findViewById(R.id.Error);
        final TextView lol = (TextView)findViewById(R.id.editText1);
        Writer.write(lol.getText().toString().getBytes());
        lol.setText("");

    }
    public void send(View sender)
    {
        ConnectThread con = new ConnectThread(Client);
        con.start();
    }
    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent)
        {
            String action = intent.getAction();
            // When discovery finds a device
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                // Get the BluetoothDevice object from the Intent
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                // Add the name and address to an array adapter to show in a ListView
                //mArrayAdapter.add(device.getName() + "\n" + device.getAddress());

                final TextView er = (TextView)findViewById(R.id.Error);
                if(device.getAddress().equals("9C:2A:70:49:61:B0") == true)
                {
                    Client = device;
                    er.setText("Connected with the target device!");
                }
            }
        }
    };
    private class ConnectThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final BluetoothDevice mmDevice;

        public ConnectThread(BluetoothDevice device) {
            // Use a temporary object that is later assigned to mmSocket,
            // because mmSocket is final
            BluetoothSocket tmp = null;
            mmDevice = device;
            UUID myuuid = UUID.fromString("94f39d29-7d6d-437d-973b-fba39e49d4ee");
            final TextView er = (TextView)findViewById(R.id.Error);
            // Get a BluetoothSocket to connect with the given BluetoothDevice
            try {
                // MY_UUID is the app's UUID string, also used by the server code
                tmp = device.createRfcommSocketToServiceRecord(myuuid);

            } catch (IOException e) {}
            ClientSocket = mmSocket = tmp;
            Writer = new ConnectedThread(ClientSocket);
        }

        public void run() {
            // Cancel discovery because it will slow down the connection
            mblue.cancelDiscovery();
            final TextView er = (TextView)findViewById(R.id.Error);
            try {
                // Connect the device through the socket. This will block
                // until it succeeds or throws an exception
                mmSocket.connect();
            } catch (IOException connectException) {
                // Unable to connect; close the socket and get out
                try {
                    mmSocket.close();
                } catch (IOException closeException) {}
                return;
            }

            // Do work to manage the connection (in a separate thread)
            //manageConnectedSocket(mmSocket);
        }

        /** Will cancel an in-progress connection, and close the socket */
        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {}
        }
    }



    public class ConnectedThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final InputStream mmInStream;
        private final OutputStream mmOutStream;

        public ConnectedThread(BluetoothSocket socket) {
            mmSocket = socket;
            InputStream tmpIn = null;
            OutputStream tmpOut = null;

            final TextView er = (TextView)findViewById(R.id.Error);
            // Get the input and output streams, using temp objects because
            // member streams are final
            try {
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) {}

            mmInStream = tmpIn;
            mmOutStream = tmpOut;

            er.setText(er.getText() + "\n" + socket.toString());
        }

        public void run() {
            byte[] buffer = new byte[1024];  // buffer store for the stream
            int bytes; // bytes returned from read()

            // Keep listening to the InputStream until an exception occurs
            while (true) {
                try {
                    // Read from the InputStream
                    bytes = mmInStream.read(buffer);
                    // Send the obtained bytes to the UI activity
                   // mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
                   //         .sendToTarget();
                } catch (IOException e) {
                    break;
                }
            }
        }

        /* Call this from the main activity to send data to the remote device */

        public void write(byte[] bytes) {
            final TextView er = (TextView)findViewById(R.id.Error);
            try {
                mmOutStream.write(bytes);

                //mmOutStream.
            } catch (IOException e) 
                {
                    er.setText(e.toString());
                }
        }

        /* Call this from the main activity to shutdown the connection */
        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) { }
        }
    }
}

Python Server:

from bluetooth import *

server_sock=BluetoothSocket( RFCOMM )
server_sock.bind(("",PORT_ANY))
server_sock.listen(1)

port = server_sock.getsockname()[1]

uuid = "94f39d29-7d6d-437d-973b-fba39e49d4ee"

advertise_service( server_sock, "SampleServer",
                   service_id = uuid,
                   service_classes = [ uuid, SERIAL_PORT_CLASS ],
                   profiles = [ SERIAL_PORT_PROFILE ], 
#                   protocols = [ OBEX_UUID ] 
                    )

print("Waiting for connection on RFCOMM channel %d" % port)

client_sock, client_info = server_sock.accept()
print("Accepted connection from ", client_info)

try:
    while True:
        data = client_sock.recv(1024)
        if len(data) == 0: break
        print("received [%s]" % data)
except IOError:
    pass

print("disconnected")

client_sock.close()
server_sock.close()
print("all done")

Any help is appreciated.

Answer 1

You have used two public classes ie public class MainActivity extends Activity{} and public class ConnectedThread extends Thread {} . But in Java there should be one public class and any number of other classes in one JavaClass file. So remove public class ConnectedThread extends Thread {} from that file and create a new Java class: public class ConnectedThread extends Thread {} in the same package.