Java APIs

Hi,

I am trying to send UDP packets using jpcap, but it always gives this Exception: Exception in thread "main" java.io.IOException:
at jpcap.JpcapSender.nativeSendPacket(Native Method)
at jpcap.JpcapSender.sendPacket(JpcapSender.java:92)

Here is the code.

public static void main(String[] args) throws Exception{
NetworkInterface device=JpcapCaptor.getDeviceList()[1];
JpcapCaptor captor=JpcapCaptor.openDevice(device,2000,false,5000);
InetAddress thisIP=null;
for(NetworkInterfaceAddress addr:device.addresses)
if(addr.address instanceof Inet4Address){
thisIP=addr.address;
break;
}
byte[] gwmac={0,-128,72,48,-89,-79};

UDPPacket udp = new UDPPacket(1000, 161);

udp.setIPv4Parameter (0,false,false,false,0,false,false,false,0,0,0,IPPacket.IPPROTO_UDP,
thisIP,InetAddress.getByName("www.seznam.cz"));

udp.data="data".getBytes();
EthernetPacket ether=new EthernetPacket();
ether.frametype=EthernetPacket.ETHERTYPE_IP;
ether.src_mac=device.mac_address;
ether.dst_mac=gwmac;
udp.datalink = ether;
JpcapSender sender=captor.getJpcapSenderInstance();
sender.sendPacket(udp);


}

I also tried some examples downloaded from the jpcap homepage, but they don't work either. I use Windows XP.

Does anybody know, where the problem is?

If anybody has a source code that works, could you please send it at tomas.klima@atlas.cz

Thanks. Tom