Connect phone error wifi hotspot: ENETUNREACH

I have an app, the app connects two phones using hotspot to send / recv file. One phone creates a hotspot (Wifi hotspot), I connect another phone with a hotspot using the code below:

            mSocket = new Socket();

            try {

                mSocket.setReuseAddress(true);
                mSocket.bind(null);
                mSocket.setPerformancePreferences(0, 1, 2);
                mSocket.setTcpNoDelay(true);
                mSocket.setSoLinger(true, 0);
                mSocket.setKeepAlive(true);

                mSocket.connect(new InetSocketAddress(mConnection.getServerAddress(),
                        mConnection.getServerPort()), SOCKET_CONNECT_TIMEOUT);

           //operation here....
            } catch (SocketException e) {
                ((HotSpotConnection)mConnection).getlocalip();
                LogUtils.LOGE(LOG_TAG, "init exception:" + e.toString());
            } catch (IOException e) {
                LogUtils.LOGE(LOG_TAG, "init exception:" + e.toString());
            }

      

        
        
        
      

    

and I got the following error:

E/MyTestWifiThread(18918): init exception:java.net.ConnectException: 
failed to connect to /192.168.43.1 (port 9876) after 30000ms: 
isConnected failed: ENETUNREACH (Network is unreachable)

      

        
        
        
      

    

Why can't I connect to the hotspot phone, I'm sure the default hotspot phone address is 192.168.43.1? because I pinged 192.168.43.1 and the hotspot phone answered.