使用后应关闭套接字:

public boolean openBT(Context context) throws IOException {
try {
    // Standard SerialPortService ID
    UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");
    mmSocket = mmDevice.createRfcommSocketToServiceRecord(uuid);
    mBluetoothAdapter.cancelDiscovery();

    mmSocket.connect();

    mmOutputStream = new DataOutputStream(mmSocket.getOutputStream());
    mmInputStream = new DataInputStream(mmSocket.getInputStream());

    mmSocket.close(); //Socket closed
} catch (NullPointerException e) {
    e.printStackTrace();
    return false;
} catch (Exception e) { 
     e.printStackTrace();
    return false;

}

return true;}