networking - Get default gateway in java

Question

I want to fetch default gateway for local machine using java. I know how to get it by executing dos or shell commands, but is there any another way to fetch? Also need to fetch primary and secondary dns ip.

Answer 1

My way is:

try(DatagramSocket s=new DatagramSocket())
{
    s.connect(InetAddress.getByAddress(new byte[]{1,1,1,1}), 0);
    return NetworkInterface.getByInetAddress(s.getLocalAddress()).getHardwareAddress();
}

Because of using datagram (UDP), it isn't connecting anywhere, so port number may be meaningless and remote address (1.1.1.1) needn't be reachable, just routable.