001: /*
002: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
003: *
004: * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
005: *
006: * The contents of this file are subject to the terms of either the GNU
007: * General Public License Version 2 only ("GPL") or the Common
008: * Development and Distribution License("CDDL") (collectively, the
009: * "License"). You may not use this file except in compliance with the
010: * License. You can obtain a copy of the License at
011: * http://www.netbeans.org/cddl-gplv2.html
012: * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
013: * specific language governing permissions and limitations under the
014: * License. When distributing the software, include this License Header
015: * Notice in each file and include the License file at
016: * nbbuild/licenses/CDDL-GPL-2-CP. Sun designates this
017: * particular file as subject to the "Classpath" exception as provided
018: * by Sun in the GPL Version 2 section of the License file that
019: * accompanied this code. If applicable, add the following below the
020: * License Header, with the fields enclosed by brackets [] replaced by
021: * your own identifying information:
022: * "Portions Copyrighted [year] [name of copyright owner]"
023: *
024: * Contributor(s):
025: *
026: * The Original Software is NetBeans. The Initial Developer of the Original
027: * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
028: * Microsystems, Inc. All Rights Reserved.
029: *
030: * If you wish your version of this file to be governed by only the CDDL
031: * or only the GPL Version 2, indicate your decision by adding
032: * "[Contributor] elects to include this software in this distribution
033: * under the [CDDL or GPL Version 2] license." If you do not indicate a
034: * single choice of license, a recipient has the option to distribute
035: * your version of this file under either the CDDL, the GPL Version 2 or
036: * to extend the choice of license to its licensees as provided above.
037: * However, if you add GPL Version 2 code and therefore, elected the GPL
038: * Version 2 license, then the option applies only if the new code is
039: * made subject to such option by the copyright holder.
040: */
041:
042: package org.netbeans.lib.collab.util;
043:
044: import java.util.*;
045: import java.net.*;
046: import java.io.*;
047: import javax.naming.*;
048: import javax.naming.directory.*;
049:
050: /**
051: * Utility class to perform DNS lookups.
052: *
053: * The original version of this code was contributed to the jdev mailing
054: * list by Matt Tucker
055: *
056: * @author Jacques Belissent
057: *
058: */
059: public class SRVLookup {
060:
061: private static DirContext context;
062:
063: static {
064: try {
065: Hashtable env = new Hashtable();
066: env.put("java.naming.factory.initial",
067: "com.sun.jndi.dns.DnsContextFactory");
068: context = new InitialDirContext(env);
069: } catch (Exception e) {
070: //Log.error(e);
071: }
072: }
073:
074: /**
075: * Returns the host name and port of a service specified by prefix
076: * for a given domain.
077: * A DNS SRV lookup for a record in the form <i>prefix</i>domain
078: * is attempted.
079: * If that lookup fails, it's assumed that the service lives at
080: * the host resolved by a DNS Address lookup at the specified
081: * domain on the specified default port.
082: *
083: * As an example, a lookup for "example.com" may return
084: * "im.example.com:5269".
085: *
086: * @param domain the domain to resolve
087: * @param prefix DNS SRV prefix of the form service.protocol.
088: * @param defaultPort port to use if none other is specified.
089: * @return a SocketAddress based on the obtained host and port
090: */
091: public static InetSocketAddress lookup(String domain,
092: String service, String transport, int defaultPort)
093: throws IllegalArgumentException, UnknownHostException,
094: NamingException {
095: if (context == null) {
096: return new InetSocketAddress(domain, defaultPort);
097: }
098:
099: String host = domain;
100: int port = defaultPort;
101:
102: Attributes dnsLookup = context.getAttributes("_" + service
103: + "._" + transport + "." + domain,
104: new String[] { "SRV" });
105: String srvRecord = (String) ((Attribute) dnsLookup.getAll()
106: .next()).get();
107: String[] srvRecordEntries = srvRecord.split(" ");
108: port = Integer
109: .parseInt(srvRecordEntries[srvRecordEntries.length - 2]);
110: host = srvRecordEntries[srvRecordEntries.length - 1];
111:
112: // Host entries in DNS should end with a ".".
113: if (host.endsWith(".")) {
114: host = host.substring(0, host.length() - 1);
115: }
116:
117: return new InetSocketAddress(host, port);
118: }
119:
120: public static InetSocketAddress XMPPServer(String domain) {
121: return XMPPServer(domain, 5269);
122: }
123:
124: public static InetSocketAddress XMPPServer(String domain,
125: int defaultPort) {
126: InetSocketAddress sa = null;
127: try {
128: sa = lookup(domain, "xmpp-server", "tcp", defaultPort);
129: } catch (Exception e) {
130: try {
131: sa = lookup(domain, "jabber", "tcp", defaultPort);
132: } catch (Exception ee) {
133: }
134: }
135:
136: if (sa == null) {
137: return new InetSocketAddress(domain, defaultPort);
138: }
139:
140: return sa;
141: }
142:
143: public static InetSocketAddress XMPPClient(String domain) {
144: return XMPPClient(domain, 5222);
145: }
146:
147: public static InetSocketAddress XMPPClient(String domain,
148: int defaultPort) {
149: InetSocketAddress sa = null;
150: try {
151: sa = lookup(domain, "xmpp-client", "tcp", defaultPort);
152: } catch (Exception e) {
153: try {
154: sa = lookup(domain, "jabber", "tcp", defaultPort);
155: } catch (Exception ee) {
156: }
157: }
158:
159: if (sa == null) {
160: return new InetSocketAddress(domain, defaultPort);
161: }
162:
163: return sa;
164: }
165:
166: /**
167: * Usage:
168: * java org.netbeans.lib.collab.util.SRVLookup domain default-port [service transport]
169: * Examples:
170: * java org.netbeans.lib.collab.util.SRVLookup jabber.org 5269
171: * java org.netbeans.lib.collab.util.SRVLookup jabber.org 5269 xmpp-server tcp
172: * java org.netbeans.lib.collab.util.SRVLookup jabber.org 5222 xmpp-client tcp
173: */
174: public static void main(String[] arg) {
175: try {
176: SocketAddress sa = null;
177: if (arg.length == 2) {
178: sa = SRVLookup.XMPPServer(arg[0], Integer
179: .parseInt(arg[1]));
180: } else if (arg.length == 4) {
181: sa = lookup(arg[0], arg[2], arg[3], Integer
182: .parseInt(arg[1]));
183: } else {
184: System.out
185: .println("Usage:\njava org.netbeans.lib.collab.util.SRVLookup domain default-port [service transport]");
186: System.exit(1);
187: }
188: System.out.println(sa);
189: //return 0;
190: } catch (Exception e) {
191: e.printStackTrace();
192: //return 1;
193: }
194: }
195: }
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