以太网发送自定义协议数据包java

        //1枚举网卡并打开设备

  jpcap.NetworkInterface[] devices = JpcapCaptor.getDeviceList();

  NetworkInterface device = devices[2];

  JpcapSender sender = null;

  //2.原始类型数据包，这种包没有首部字节。UDPPacket、IPPacket有首部字节

        //需要设置udp.setIPv4Parameter(0,false,false,false,0,false,false,false,0,0,255,

        //   230,//230未定义协议

        //   InetAddress.getByName("192.168.1.100"), 

        //   InetAddress.getByName("192.168.1.102"));

  Packet udp = new Packet();

  try {

      sender = JpcapSender.openDevice(device);

  } catch (IOException e) {

   e.printStackTrace();

  }

  EthernetPacket ether = new EthernetPacket();

  //设置自定义协议类型

  int type = Integer.decode("0x7799");

  ether.frametype = (short)type;

  byte[] desmac = stomac(macAddress);//目标mac地址

  byte[] srcmac = null;

  try {

   srcmac = stomac(getLocalMac(InetAddress.getLocalHost()));

  } catch (SocketException e) {

   e.printStackTrace();

  } catch (UnknownHostException e) {

   e.printStackTrace();

  } // 本机MAC数组

  ether.src_mac = srcmac;

  ether.dst_mac = desmac;

  udp.datalink = ether;

  //设置字节的数据以及长度

   byte[] data = new byte[54];

      String typeStr = "hello";

         byte[] types = ByteUtil.ToByte(typeStr);

         for (int i = 0; i < 2; i++) {

         data[i] = types[i];

         }

   udp.data = data;

   sender.sendPacket(udp);