I need to get the DNS address, for example "http://stackoverflow.com/questions/ask". I used the following code and able to get in the form of 192.X.X.X.
Hashtable env = new Hashtable();
env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.dns.DnsContextFactory");
DirContext ictx = new InitialDirContext(env);
String dnsServers = (String) ictx.getEnvironment().get("java.naming.provider.url");
System.out.println("DNS Servers: " + dnsServers );
InetAddress ia = InetAddress.getByAddress(new byte[] {74,125,127,106});
// or
ia = InetAddress.getByName("74.125.127.106");
System.out.println(ia.getCanonicalHostName());
CodingForums similar question -- see post #5 (DISCLAIMER: Code is not mine, not tested by me)
Code from linked source:
/**
* 25 Nov 2009 REVERSE DNS LOOKUP USING JNDI
* In this example the IP being looked up is 211.21.152.4
* The octets are reversed (4.152.21.211)
* and appended to the in-addr.arpa zone:
* 4.152.21.211.in-addr.arpa
*/
import javax.naming.*;
import javax.naming.directory.*;
import java.util.*;
public class dns {
public static void main(String[] args) {
try {
Hashtable env = new Hashtable();
env.put("java.naming.factory.initial","com.sun.jndi.dns.DnsContextFactory");
DirContext ctx = new InitialDirContext(env);
Attributes attrs = ctx.getAttributes("4.152.21.211.in-addr.arpa",new String[] {"PTR"});
for (NamingEnumeration ae = attrs.getAll();ae.hasMoreElements();) {
Attribute attr = (Attribute)ae.next();
String attrId = attr.getID();
for (Enumeration vals = attr.getAll();vals.hasMoreElements();
System.out.println(attrId + ": " + vals.nextElement()));
}
ctx.close();
}
catch(Exception e) {
System.out.println("NO REVERSE DNS");
}
}
}