多播Android +网络共享＆＃34;网络无法访问＆＃34;

Question

以下选项显示错误

  

Android应用程序+多播+绑定+单元格数据关闭

如果我连接到wifi router，则不会发生错误。我有什么不对或 android + multicast + tethering impossible ？

public class Multicast {
final static String INET_ADDR = "224.0.0.1";
final static int PORT = 8888;

private Context mContext;

public Multicast(Context context) {
    mContext = context;
}

public static NetworkInterface getWlanEth() {
    final String TAG = "NetworkInterface";
    Enumeration<NetworkInterface> enumeration = null;
    try {
        enumeration = NetworkInterface.getNetworkInterfaces();
    } catch (SocketException e) {
        e.printStackTrace();
    }
    NetworkInterface wlan0 = null;
    StringBuilder sb = new StringBuilder();
    while (enumeration.hasMoreElements()) {
        wlan0 = enumeration.nextElement();
        sb.append(wlan0.getName() + " ");
        if (wlan0.getName().equals("wlan0")) {
            return wlan0;
        }
    }

    return null;
}

@TargetApi(Build.VERSION_CODES.KITKAT)
public void startMulticastServer() {
    Thread sendThread = new Thread(new Runnable() {
        DatagramSocket serverSocket;

        @Override
        public void run() {
            try {

                if (serverSocket == null) {
                    serverSocket = new DatagramSocket(null);
                    serverSocket.setReuseAddress(true);
                    serverSocket.setBroadcast(true);
                    serverSocket.bind(new InetSocketAddress(PORT));
                    serverSocket.setSoTimeout(15000);
                }
                for (int i = 0; i < 5; i++) {
                    String msg = "Sent message no " + i;
                    InetAddress group = InetAddress.getByName(INET_ADDR);
                    DatagramPacket msgPacket = new DatagramPacket(msg.getBytes(),
                            msg.getBytes().length, group, PORT);

                    serverSocket.send(msgPacket);
                    String TAG = "Multicast-send";
                    Log.i(TAG, "Socket 1 send msg: " + msg);
                    Thread.sleep(500);
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            try {
                serverSocket.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
    sendThread.start();
}


public void startMulticastClient() {

    Thread getThread = new Thread(new Runnable() {
        byte[] buf = new byte[256];

        @TargetApi(Build.VERSION_CODES.KITKAT)
        @Override
        public void run() {
            //Acquire the MulticastLock
            WifiManager wifi = (WifiManager) mContext.getSystemService(Context.WIFI_SERVICE);
            MulticastLock multicastLock = wifi.createMulticastLock("multicastLock");
            multicastLock.setReferenceCounted(true);
            multicastLock.acquire();
            // Create a new Multicast socket (that will allow other sockets/programs
            // to join it as well.
            try {
                MulticastSocket clientSocket = new MulticastSocket(PORT);
                //Joint the Multicast group.
                clientSocket.joinGroup(new InetSocketAddress(InetAddress.getByName(INET_ADDR), PORT), getWlanEth());
                clientSocket.setLoopbackMode(true);

                while (true) {
                    // Receive the information and print it.
                    DatagramPacket msgPacket = new DatagramPacket(buf, buf.length);
                    clientSocket.receive(msgPacket);
                    String msg = new String(msgPacket.getData());
                    String TAG = "Multicast-get";
                    Log.i(TAG, "Socket 1 received msg: " +msgPacket.getAddress()+" : "+ InetAddress.getByName(INET_ADDR) + " : " +msg);
                }
            } catch (IOException ex) {
                multicastLock.release();
                ex.printStackTrace();
            }
            multicastLock.release();
        }
    });
    getThread.start();
  }
}