1/**
2 * Copyright 2013 Florian Schmaus
3 *
4 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16package org.jivesoftware.smack.util.dns;
17
18import java.util.ArrayList;
19import java.util.List;
20
21import org.xbill.DNS.Lookup;
22import org.xbill.DNS.Record;
23import org.xbill.DNS.Type;
24
25/**
26 * This implementation uses the <a href="http://www.dnsjava.org/">dnsjava</a> implementation for resolving DNS addresses.
27 *
28 */
29public class DNSJavaResolver implements DNSResolver {
30
31    private static DNSJavaResolver instance = new DNSJavaResolver();
32
33    private DNSJavaResolver() {
34
35    }
36
37    public static DNSResolver getInstance() {
38        return instance;
39    }
40
41    @Override
42    public List<SRVRecord> lookupSRVRecords(String name) {
43        List<SRVRecord> res = new ArrayList<SRVRecord>();
44
45        try {
46            Lookup lookup = new Lookup(name, Type.SRV);
47            Record recs[] = lookup.run();
48            if (recs == null)
49                return res;
50
51            for (Record record : recs) {
52                org.xbill.DNS.SRVRecord srvRecord = (org.xbill.DNS.SRVRecord) record;
53                if (srvRecord != null && srvRecord.getTarget() != null) {
54                    String host = srvRecord.getTarget().toString();
55                    int port = srvRecord.getPort();
56                    int priority = srvRecord.getPriority();
57                    int weight = srvRecord.getWeight();
58
59                    SRVRecord r;
60                    try {
61                        r = new SRVRecord(host, port, priority, weight);
62                    } catch (Exception e) {
63                        continue;
64                    }
65                    res.add(r);
66                }
67            }
68
69        } catch (Exception e) {
70        }
71        return res;
72    }
73}
74