1 /*

     2  * Copyright 2002-2004 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  */

    23 

    24 import java.net.InetAddress;

    25 import java.util.*;

    26 import javax.naming.*;

    27 import javax.naming.directory.*;

    28 

    29 /*

    30  * Tests if a canonical name (CNAME) record exists for a

    31  * specified host - throws exception if DNS isn't configured

    32  * or there isn't a CNAME record.

    33  */

    34 

    35 public class CanonicalName {

    36 

    37     public static void main(String args[]) throws Exception {

    38         final Hashtable<String,String> env = new Hashtable<String,String>();

    39         env.put("java.naming.factory.initial",

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

    41         DirContext ctx = new InitialDirContext(env);

    42 

    43         String ids[] = { "CNAME" };

    44         Attributes attrs = ctx.getAttributes(args[0], ids);

    45 

    46         NamingEnumeration ne = attrs.getAll();

    47         if (!ne.hasMoreElements()) {

    48             throw new Exception("no CNAME record");

    49         }

    50 

    51         // print out the CNAME records

    52 

    53         while (ne.hasMoreElements()) {

    54             Attribute attr = (Attribute)ne.next();

    55             for (NamingEnumeration e = attr.getAll(); e.hasMoreElements();) {

    56                 System.out.println(args[0] + " -> " + e.next());

    57             }

    58         }

    59 

    60     }

    61 }