Question

I want write a small program to get IP Address of some websites by manual send and receive data packet from Google DNS, Open DNS.

How can help me.

I wrote this but not work properly.

public static void main(String args[]) throws Exception
{
    String str="stackoverflow.com";
    DatagramPacket dp=new DatagramPacket(str.getBytes(),str.length());
    DatagramSocket ds=new DatagramSocket();

    dp.setAddress(InetAddress.getByName("8.8.8.8"));
    dp.setPort(53);

    ds.send(dp);
    System.out.println("SENDED");

    byte[] receive=new byte[1024];
    dp.setData(receive);

    System.out.println("PREPARING FOR RECEIVE : ");
    ds.receive(dp);

    System.out.println(new String(receive));
}

Answer 1

you will need to implement the DNS protocol — a starting point could be https://www.rfc-editor.org/rfc/rfc1035