Android 获取本机Ip 和 Mac

public class MainActivity extends Activity {

  private EditText ed1, ed2;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ed1 = (EditText) findViewById(R.id.et1);
    ed2 = (EditText) findViewById(R.id.et2);

    ed1.setText(getIP());
    ed2.setText(getLocalMacAddressFromIp(getIP()));

    new Thread() {

      @Override
      public void run() {

        try {
          sendInfo();
        } catch (Exception e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
        }
      }

    }.start();

  }

  public void sendInfo() throws Exception {//可以通过 DatagramPacket 的getAddress()方法获取ip

    final String GROUP_ADDR = "224.224.224.224";
    final int PORT = 4444;
    MulticastSocket ms = new MulticastSocket(PORT);
    InetAddress addr = InetAddress.getByName(GROUP_ADDR);
    ms.joinGroup(addr);

    String info = "hello";
    byte[] buf = info.getBytes();
    DatagramPacket dp = new DatagramPacket(buf, buf.length, addr, PORT);

    while (true) {
      Thread.sleep(2000);
      ms.send(dp);
    }
  }

  public static String getIP() {
    try {
      for (Enumeration en = NetworkInterface
          .getNetworkInterfaces(); en.hasMoreElements();) {
        NetworkInterface intf = en.nextElement();
        for (Enumeration enumIpAddr = intf
            .getInetAddresses(); enumIpAddr.hasMoreElements();) {
          InetAddress inetAddress = enumIpAddr.nextElement();
          if (!inetAddress.isLoopbackAddress()
              && !inetAddress.isLinkLocalAddress()) {
            return inetAddress.getHostAddress().toString();
          }
        }
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
    return null;
  }

  public static String getLocalMacAddressFromIp(String ipStr)

  {

    String mac_s = "";

    try {

      byte[] mac;

      NetworkInterface ne = NetworkInterface.getByInetAddress(InetAddress
          .getByName(ipStr));

      mac = ne.getHardwareAddress();
      mac_s = byte2hex(mac);

    } catch (Exception e) {

      e.printStackTrace();

    }

    return mac_s;

  }

  public static String byte2hex(byte[] b)

  {

    StringBuffer hs = new StringBuffer(b.length);

    String stmp = "";

    int len = b.length;

    for (int n = 0; n < len; n++)

    {

      stmp = Integer.toHexString(b[n] & 0xFF);

      if (stmp.length() == 1) {

        hs = hs.append("0").append(stmp);

      } else {

        hs = hs.append(stmp);

      }
    }
    return String.valueOf(hs);
  }