jnetpcap java 网络抓包

Question

我想实现的功能：

1.开启进程进行网络抓包

2.运行一段程序，截取这段程序产生的数据包

3.停止抓包进程，保存数据包到本地

但我看到jnetpcap上的示例代码只能抓去特定个数的数据包，离我想要的效果有点差距，可能是我自己没有把

文档看透，哪位写过类似代码的请指点一下，谢谢！

jnetpcap网站：http://www.jnetpcap.com

抓取10个数据包的代码行：

pcap.loop(10, dumpHandler, dumper);

import java.io.File;  
import java.nio.ByteBuffer;  
import java.util.ArrayList;  
import java.util.List;  
  
import org.jnetpcap.Pcap;  
import org.jnetpcap.PcapDumper;  
import org.jnetpcap.PcapHandler;  
import org.jnetpcap.PcapIf;  
  
  
public class PcapDumperExample {  
  public static void main(String[] args) {  
    List<PcapIf> alldevs = new ArrayList<PcapIf>(); // Will be filled with NICs  
    StringBuilder errbuf = new StringBuilder();     // For any error msgs  
  
    /*************************************************************************** 
     * First get a list of devices on this system 
     **************************************************************************/  
    int r = Pcap.findAllDevs(alldevs, errbuf);  
    if (r == Pcap.NOT_OK || alldevs.isEmpty()) {  
      System.err.printf("Can't read list of devices, error is %sn",   
        errbuf.toString());  
      return;  
    }  
    PcapIf device = alldevs.get(1); // We know we have atleast 1 device  
  
    /*************************************************************************** 
     * Second we open up the selected device 
     **************************************************************************/  
    int snaplen = 64 * 1024;           // Capture all packets, no trucation  
    int flags = Pcap.MODE_PROMISCUOUS; // capture all packets  
    int timeout = 10 * 1000;           // 10 seconds in millis  
    Pcap pcap = Pcap.openLive(device.getName(), snaplen, flags, timeout, errbuf);  
    if (pcap == null) {  
      System.err.printf("Error while opening device for capture: %sn",   
        errbuf.toString());  
      return;  
    }  
          
    /*************************************************************************** 
     * Third we create a PcapDumper and associate it with the pcap capture 
     ***************************************************************************/  
    String ofile = "tmp-capture-file.cap";  
    PcapDumper dumper = pcap.dumpOpen(ofile); // output file  
  
    /*************************************************************************** 
     * Fouth we create a packet handler which receives packets and tells the  
     * dumper to write those packets to its output file 
     **************************************************************************/  
    PcapHandler<PcapDumper> dumpHandler = new PcapHandler<PcapDumper>() {  
  
      public void nextPacket(PcapDumper dumper, long seconds, int useconds,  
        int caplen, int len, ByteBuffer buffer) {  
  
        dumper.dump(seconds, useconds, caplen, len, buffer);  
      }  
    };  
  
    /*************************************************************************** 
     * Fifth we enter the loop and tell it to capture 10 packets. We pass 
     * in the dumper created in step 3 
     **************************************************************************/  
    pcap.loop(10, dumpHandler, dumper);  
          
    File file = new File(ofile);  
    System.out.printf("%s file has %d bytes in it!n", ofile, file.length());  
          
  
    /*************************************************************************** 
     * Last thing to do is close the dumper and pcap handles 
     **************************************************************************/  
    dumper.close(); // Won't be able to delete without explicit close  
    pcap.close();  
          
    if (file.exists()) {  
      file.delete(); // Cleanup  
    }  
  }  
}

Answer 1

http://www.oschina.net/code/snippet_214658_44034