java使用jpcap抓包工具获得本机发送的所有tcp请求，根据tcp请求的内容可以调试某个应用启动后对外发送的相关http请求或者sql连接请求，这样可以很好的调试我们的程序。很不错的一种应用无侵入性的调试本机发送的http接口，sql连接接口等。

import java.io.UnsupportedEncodingException;  import java.net.InetAddress;    import jpcap.*;  import jpcap.packet.EthernetPacket;  import jpcap.packet.Packet;  import jpcap.packet.TCPPacket;    class Tcpdump implements PacketReceiver {   public void receivePacket(Packet packet) {  //  System.out.println(packet);      if (packet instanceof TCPPacket) {     TCPPacket tcpPacket = (TCPPacket) packet;     if(tcpPacket.src_ip.getHostAddress().equals(getIp())){      EthernetPacket ethernetPacket = (EthernetPacket) packet.datalink;      System.out.print("源IP：" + tcpPacket.src_ip + "  目的IP："        + tcpPacket.dst_ip + "发送端口：" + tcpPacket.src_port        + " 接收端口：" + tcpPacket.dst_port + "\n");      System.out        .print("源MAC：" + ethernetPacket.getSourceAddress()          + " 目的MAC："          + ethernetPacket.getDestinationAddress() + "\n");      System.out.print("协议：" + tcpPacket.protocol + "\n");      System.out.print("数据：\n");      try {       System.out.println(new String(tcpPacket.data,"utf-8"));      } catch (UnsupportedEncodingException e) {       // TODO Auto-generated catch block       e.printStackTrace();      }  //    for (int i = 0; i < tcpPacket.data.length; i++)  //     System.out.print((char) tcpPacket.data[i]);      }    }     }      public static String getIp(){       InetAddress inet = null;    try {     inet = InetAddress.getLocalHost();        String ip = inet.getHostAddress();  //在某些linux机器上取到的ip是host绑定的本机ip，即127.0.0.1        return ip;    }catch(Exception e){         }    return null;   }  } 

我先启动给一个查询数据库的一个应用，然后再启动下面的程序，

输出结果如下：