001/**
002 *
003 * Copyright 2013-2014 Florian Schmaus
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smack.util.dns.dnsjava;
018
019import java.util.ArrayList;
020import java.util.List;
021
022import org.jivesoftware.smack.initializer.SmackInitializer;
023import org.jivesoftware.smack.util.DNSUtil;
024import org.jivesoftware.smack.util.dns.DNSResolver;
025import org.jivesoftware.smack.util.dns.SRVRecord;
026import org.xbill.DNS.Lookup;
027import org.xbill.DNS.Record;
028import org.xbill.DNS.TextParseException;
029import org.xbill.DNS.Type;
030
031/**
032 * This implementation uses the <a href="http://www.dnsjava.org/">dnsjava</a> implementation for resolving DNS addresses.
033 *
034 */
035public class DNSJavaResolver implements SmackInitializer, DNSResolver {
036    
037    private static DNSJavaResolver instance = new DNSJavaResolver();
038
039    public static DNSResolver getInstance() {
040        return instance;
041    }
042
043    @Override
044    public List<SRVRecord> lookupSRVRecords(String name) throws TextParseException {
045        List<SRVRecord> res = new ArrayList<SRVRecord>();
046
047        Lookup lookup = new Lookup(name, Type.SRV);
048        Record[] recs = lookup.run();
049        if (recs == null)
050            return res;
051
052        for (Record record : recs) {
053            org.xbill.DNS.SRVRecord srvRecord = (org.xbill.DNS.SRVRecord) record;
054            if (srvRecord != null && srvRecord.getTarget() != null) {
055                String host = srvRecord.getTarget().toString();
056                int port = srvRecord.getPort();
057                int priority = srvRecord.getPriority();
058                int weight = srvRecord.getWeight();
059
060                SRVRecord r = new SRVRecord(host, port, priority, weight);
061                res.add(r);
062            }
063        }
064
065        return res;
066    }
067
068    public static void setup() {
069        DNSUtil.setDNSResolver(getInstance());
070    }
071
072    @Override
073    public List<Exception> initialize() {
074        setup();
075        return null;
076    }
077
078}