01: /****************************************************************
02: * Licensed to the Apache Software Foundation (ASF) under one *
03: * or more contributor license agreements. See the NOTICE file *
04: * distributed with this work for additional information *
05: * regarding copyright ownership. The ASF licenses this file *
06: * to you under the Apache License, Version 2.0 (the *
07: * "License"); you may not use this file except in compliance *
08: * with the License. You may obtain a copy of the License at *
09: * *
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: ****************************************************************/package org.apache.james.services;
19:
20: import java.util.Collection;
21: import java.util.Iterator;
22:
23: /**
24: * Provides abstraction for DNS resolutions. The interface is Mail specific.
25: * It may be a good idea to make the interface more generic or expose
26: * commonly needed DNS methods.
27: *
28: */
29: public interface DNSServer {
30:
31: /**
32: * The component role used by components implementing this service
33: */
34: String ROLE = "org.apache.james.services.DNSServer";
35:
36: /**
37: * <p>Get a priority-sorted collection of DNS MX records for a given hostname</p>
38: *
39: * <p>TODO: Change this to a list, as not all collections are sortable</p>
40: *
41: * @param hostname the hostname to check
42: * @return collection of strings representing MX record values.
43: */
44: Collection findMXRecords(String hostname);
45:
46: /**
47: * Performs DNS lookups as needed to find servers which should or might
48: * support SMTP. Returns one SMTPHostAddresses for each such host
49: * discovered by DNS. If no host is found for domainName, the Iterator
50: * returned will be empty and the first call to hasNext() will return
51: * false.
52: * @param domainName the String domain for which SMTP host addresses are
53: * sought.
54: * @return an Enumeration in which the Objects returned by next()
55: * are instances of SMTPHostAddresses.
56: */
57: Iterator getSMTPHostAddresses(String domainName);
58:
59: }
|