View Javadoc

1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *  
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *  
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License. 
18   *  
19   */
20  
21  package org.apache.directory.server.dns.io.decoder;
22  
23  
24  import java.io.IOException;
25  import java.util.HashMap;
26  import java.util.Map;
27  
28  import org.apache.directory.server.dns.store.DnsAttribute;
29  import org.apache.mina.common.ByteBuffer;
30  
31  
32  /**
33   * A decoder for MX records.  MX records are encoded as per RFC-1035:
34   * 
35   * <pre>
36   *   3.3.9. MX RDATA format
37   *
38   *     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
39   *     |                  PREFERENCE                   |
40   *     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
41   *     /                   EXCHANGE                    /
42   *     /                                               /
43   *     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
44   *
45   *   where:
46   *
47   *   PREFERENCE
48   *     A 16 bit integer which specifies the preference given to this RR among 
49   *     others at the same owner. Lower values are preferred. 
50   *     
51   *   EXCHANGE
52   *     A <domain-name> which specifies a host willing to act as a mail exchange
53   *     for the owner name.
54   * </pre>
55   * 
56   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
57   * @version $Rev$, $Date$
58   */
59  public class MailExchangeRecordDecoder implements RecordDecoder
60  {
61      public Map<String, Object> decode( ByteBuffer byteBuffer, short length ) throws IOException
62      {
63          Map<String, Object> attributes = new HashMap<String, Object>();
64          attributes.put( DnsAttribute.MX_PREFERENCE, byteBuffer.getShort() );
65          attributes.put( DnsAttribute.DOMAIN_NAME, DnsMessageDecoder.getDomainName( byteBuffer ) );
66          return attributes;
67      }
68  }