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dns lookup menggunakan JNDI

import javax.naming.*;

import com.sun.jndi.dns.*;

import java.util.Hashtable;



public class TestDNS {

  public static void main(String[] argv) {

     Name cn = null;

     String name = argv[0];

     Hashtable env = new Hashtable();

     env.put(Context.INITIAL_CONTEXT_FACTORY,

		    "com.sun.jndi.dns.DnsContextFactory");

     env.put(Context.PROVIDER_URL, "dns://IP for DNS Server/");



     try {

        // Create the initial context

        Context ctx = new InitialContext(env);

        // print the fully qualified name (.)

        System.out.println("Name in namespace: "+ctx.getNameInNamespace());

        // retrieve the parser associated with the named context

        NameParser np = ctx.getNameParser(ctx.getNameInNamespace());

	 if (argv.length != 1) {

           System.out.println("Usage: java TestDNS ");

           System.exit(-1);

        }

        // parse the name into its components and print them

        cn = np.parse(name);

        System.out.println("Name is: "+cn.toString());

        System.out.println("The parsed name has "+cn.size()+" components:");

        for (int i=0; i lt cn.size(); i++){

           System.out.println(cn.get(i));

        }

        System.out.print("Trying to lookup ");

        // get the prefix (domain) and suffix (hostname)

        Name domain = cn.getPrefix(cn.size()-1);

        Name host = cn.getSuffix(cn.size()-1);

        System.out.println("DNS Host: "+host+" Domain: "+domain);

        // retrieve the named object

        Object obj = ctx.lookup(domain);

        System.out.println(domain.toString()+" is bound to: "+obj);

        // retrieve and print the environment in effect

        System.out.println("Domain properties: "+ ((Context)obj).getEnvironment());

        // retrieve and print the IP address (the DNS A records)

        System.out.println("IP for: "+cn+ " is: "+

                           ((DnsContext)obj).getAttributes(host, new String[]{"A"}));



        // we're done so close the context

        ctx.close();

     } catch (NamingException e) {

        System.err.println("Problem looking up " + cn + ": " + e);

     }

  }

}

Before you run this application, make sure you specify the IP address for the DNS server.

Here is a sample run:

prompt> java TestDNS prep.ai.mit.edu



Name in namespace: .

Name is: prep.ai.mit.edu

The parsed name has 4 components:

edu

mit

ai

prep

Trying to lookup DNS Host: prep Domain: ai.mit.edu

ai.mit.edu is bound to: com.sun.jndi.dns.DnsContext@b89838

Domain properties: {java.naming.provider.url=dns://IP for DNS Server/, java.namin

g.factory.initial=com.sun.jndi.dns.DnsContextFactory}

IP for: prep.ai.mit.edu is: {a=A: 199.232.41.9}

posted by fakirpena @ 6:39 PM