正在从pcap数据包读取标头信息

Question

我使用以下代码从存储在pcap文件中的数据包中读取源和目标IP。public void nextPacket（PcapPacket数据包，字符串用户）｛

        Ip4 ip = new Ip4();
                    Ethernet eth=new Ethernet();
                    String sIP;
                    String dIP;
                    int totalLength=0;
                    if (packet.hasHeader(ip) == false){
                        return;
                    }
                     totalLength = totalLength+ ip.getPayloadLength();
                     sIP = org.jnetpcap.packet.format.FormatUtils.ip(ip.source());
                     dIP = org.jnetpcap.packet.format.FormatUtils.ip(ip.destination());
                     System.out.println("SIP = "+sIP+"  "+"destIP = "+dIP+" "+"Payload Length = "+ip.getPayloadLength());
                     System.out.println("Total Length = "+totalLength);
            }   

但它什么也没显示，有带头的数据包。请帮帮我。

Answer 1

PcapPacketHandler<String> jpacketHandler = new PcapPacketHandler<String>() {
        final Ip4 ip = new Ip4();
        public void nextPacket(PcapPacket packet, String user) {
            if(packet.hasHeader(Ip4.ID)){
                packet.getHeader(ip);
                byte[] dIP = new byte[4], sIP = new byte[4];
                dIP = packet.getHeader(ip).destination();
                sIP = packet.getHeader(ip).source();
                String sourceIP = FormatUtils.ip(sIP);
                String destinationIP = FormatUtils.ip(dIP);
                System.out.printf("tcp.ip_src=%s%n",sourceIP);
                System.out.printf("tcp.ip_dest=%s%n",destinationIP);
            }
        }
    };

Answer 2

什么意思？它只是因为数据包没有标题而返回，还是在你端的代码中打印null？我不得不用这些小信息猜测，要么数据包没有ip报头。