1 /*
2 * Copyright 2009 Red Hat, Inc.
3 *
4 * Red Hat licenses this file to you under the Apache License, version 2.0
5 * (the "License"); you may not use this file except in compliance with the
6 * License. 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, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package org.jboss.netty.channel.local;
17
18 import java.net.SocketAddress;
19
20 /**
21 * An endpoint in the local transport. Each endpoint is identified by a unique
22 * case-insensitive string, except for the pre-defined value called
23 * {@code "ephemeral"}.
24 *
25 * <h3>Ephemeral Address</h3>
26 *
27 * An ephemeral address is an anonymous address which is assigned temporarily
28 * and is released as soon as the connection is closed. All ephemeral addresses
29 * have the same ID, {@code "ephemeral"}, but they are not equal to each other.
30 *
31 * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
32 * @author Andy Taylor (andy.taylor@jboss.org)
33 * @author <a href="http://gleamynode.net/">Trustin Lee</a>
34 * @version $Rev: 2241 $, $Date: 2010-04-16 13:12:43 +0900 (Fri, 16 Apr 2010) $
35 *
36 * @apiviz.landmark
37 */
38 public final class LocalAddress extends SocketAddress implements Comparable<LocalAddress> {
39
40 private static final long serialVersionUID = -3601961747680808645L;
41
42 public static final String EPHEMERAL = "ephemeral";
43
44 private final String id;
45 private final boolean ephemeral;
46
47 /**
48 * Creates a new instance with the specified ID.
49 */
50 public LocalAddress(int id) {
51 this(String.valueOf(id));
52 }
53
54 /**
55 * Creates a new instance with the specified ID.
56 */
57 public LocalAddress(String id) {
58 if (id == null) {
59 throw new NullPointerException("id");
60 }
61 id = id.trim().toLowerCase();
62 if (id.length() == 0) {
63 throw new IllegalArgumentException("empty id");
64 }
65 this.id = id;
66 ephemeral = id.equals("ephemeral");
67 }
68
69 /**
70 * Returns the ID of this address.
71 */
72 public String getId() {
73 return id;
74 }
75
76 /**
77 * Returns {@code true} if and only if this address is ephemeral.
78 */
79 public boolean isEphemeral() {
80 return ephemeral;
81 }
82
83 @Override
84 public int hashCode() {
85 if (ephemeral) {
86 return System.identityHashCode(this);
87 } else {
88 return id.hashCode();
89 }
90 }
91
92 @Override
93 public boolean equals(Object o) {
94 if (!(o instanceof LocalAddress)) {
95 return false;
96 }
97
98 if (ephemeral) {
99 return this == o;
100 } else {
101 return getId().equals(((LocalAddress) o).getId());
102 }
103 }
104
105 // FIXME: This comparison is broken! Assign distinct port numbers for
106 // ephemeral ports, just like O/S does for port number 0. It will
107 // break backward compatibility though.
108
109 public int compareTo(LocalAddress o) {
110 if (ephemeral) {
111 if (o.ephemeral) {
112 if (this == o){
113 return 0;
114 }
115
116 int a = System.identityHashCode(this);
117 int b = System.identityHashCode(this);
118 if (a < b) {
119 return -1;
120 } else if (a > b) {
121 return 1;
122 } else {
123 throw new Error(
124 "Two different ephemeral addresses have " +
125 "same identityHashCode.");
126 }
127 } else {
128 return 1;
129 }
130 } else {
131 if (o.ephemeral) {
132 return -1;
133 } else {
134 return getId().compareTo(o.getId());
135 }
136 }
137 }
138
139 @Override
140 public String toString() {
141 return "local:" + getId();
142 }
143 }