src/org/ibex/mail/DNSUtil.java

   1 package org.ibex.mail;
   2 import java.io.*;
   3 import java.util.*;
   4 import java.net.*;
   5 import org.xbill.DNS.*;
   6 import org.xbill.DNS.Message;
   7
   8 public class DNSUtil {
   9
  10     public static String reverseLookup(InetAddress ip) throws IOException {
  11         Resolver res = new ExtendedResolver();
  12         Message response =
  13             res.send(Message.newQuery(Record.newRecord(ReverseMap.fromAddress(ip), Type.PTR, DClass.IN)));
  14         Record[] answers = response.getSectionArray(Section.ANSWER);
  15         return answers.length==0 ? null : answers[0].rdataToString();
  16     }
  17
  18 }