1 /*
2 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package java.net;
26
27 import java.io.IOException;
28 import java.io.InvalidObjectException;
29 import java.io.ObjectInputStream;
30 import java.io.ObjectOutputStream;
31 import java.io.ObjectStreamException;
32 import java.io.ObjectStreamField;
33
34 /**
35 *
36 * This class implements an IP Socket Address (IP address + port number)
37 * It can also be a pair (hostname + port number), in which case an attempt
38 * will be made to resolve the hostname. If resolution fails then the address
39 * is said to be <I>unresolved</I> but can still be used on some circumstances
40 * like connecting through a proxy.
41 * <p>
42 * It provides an immutable object used by sockets for binding, connecting, or
43 * as returned values.
44 * <p>
45 * The <i>wildcard</i> is a special local IP address. It usually means "any"
46 * and can only be used for {@code bind} operations.
47 *
48 * @see java.net.Socket
49 * @see java.net.ServerSocket
50 * @since 1.4
51 */
52 public class InetSocketAddress
53 extends SocketAddress
54 {
55 // Private implementation class pointed to by all public methods.
56 private static class InetSocketAddressHolder {
57 // The hostname of the Socket Address
58 private String hostname;
59 // The IP address of the Socket Address
60 private InetAddress addr;
61 // The port number of the Socket Address
62 private int port;
63
64 private InetSocketAddressHolder(String hostname, InetAddress addr, int port) {
65 this.hostname = hostname;
66 this.addr = addr;
67 this.port = port;
68 }
69
70 private int getPort() {
71 return port;
72 }
73
74 private InetAddress getAddress() {
75 return addr;
76 }
77
78 private String getHostName() {
79 if (hostname != null)
80 return hostname;
81 if (addr != null)
82 return addr.getHostName();
83 return null;
84 }
85
86 private String getHostString() {
87 if (hostname != null)
88 return hostname;
89 if (addr != null) {
90 if (addr.holder().getHostName() != null)
91 return addr.holder().getHostName();
92 else
93 return addr.getHostAddress();
94 }
95 return null;
96 }
97
98 private boolean isUnresolved() {
99 return addr == null;
100 }
101
102 @Override
103 public String toString() {
104 if (isUnresolved()) {
105 return hostname + ":" + port;
106 } else {
107 return addr.toString() + ":" + port;
108 }
109 }
110
111 @Override
112 public final boolean equals(Object obj) {
113 if (obj == null || !(obj instanceof InetSocketAddressHolder))
114 return false;
115 InetSocketAddressHolder that = (InetSocketAddressHolder)obj;
116 boolean sameIP;
117 if (addr != null)
118 sameIP = addr.equals(that.addr);
119 else if (hostname != null)
120 sameIP = (that.addr == null) &&
121 hostname.equalsIgnoreCase(that.hostname);
122 else
123 sameIP = (that.addr == null) && (that.hostname == null);
124 return sameIP && (port == that.port);
125 }
126
127 @Override
128 public final int hashCode() {
129 if (addr != null)
130 return addr.hashCode() + port;
131 if (hostname != null)
132 return hostname.toLowerCase().hashCode() + port;
133 return port;
134 }
135 }
136
137 private final transient InetSocketAddressHolder holder;
138
139 private static final long serialVersionUID = 5076001401234631237L;
140
141 private static int checkPort(int port) {
142 if (port < 0 || port > 0xFFFF)
143 throw new IllegalArgumentException("port out of range:" + port);
144 return port;
145 }
146
147 private static String checkHost(String hostname) {
148 if (hostname == null)
149 throw new IllegalArgumentException("hostname can't be null");
150 return hostname;
151 }
152
153 /**
154 * Creates a socket address where the IP address is the wildcard address
155 * and the port number a specified value.
156 * <p>
157 * A valid port value is between 0 and 65535.
158 * A port number of {@code zero} will let the system pick up an
159 * ephemeral port in a {@code bind} operation.
160 *
161 * @param port The port number
162 * @throws IllegalArgumentException if the port parameter is outside the specified
163 * range of valid port values.
164 */
165 public InetSocketAddress(int port) {
166 this(InetAddress.anyLocalAddress(), port);
167 }
168
169 /**
170 *
171 * Creates a socket address from an IP address and a port number.
172 * <p>
173 * A valid port value is between 0 and 65535.
174 * A port number of {@code zero} will let the system pick up an
175 * ephemeral port in a {@code bind} operation.
176 * <P>
177 * A {@code null} address will assign the <i>wildcard</i> address.
178 *
179 * @param addr The IP address
180 * @param port The port number
181 * @throws IllegalArgumentException if the port parameter is outside the specified
182 * range of valid port values.
183 */
184 public InetSocketAddress(InetAddress addr, int port) {
185 holder = new InetSocketAddressHolder(
186 null,
187 addr == null ? InetAddress.anyLocalAddress() : addr,
188 checkPort(port));
189 }
190
191 /**
192 *
193 * Creates a socket address from a hostname and a port number.
194 * <p>
195 * An attempt will be made to resolve the hostname into an InetAddress.
196 * If that attempt fails, the address will be flagged as <I>unresolved</I>.
197 * <p>
198 * If there is a security manager, its {@code checkConnect} method
199 * is called with the host name as its argument to check the permission
200 * to resolve it. This could result in a SecurityException.
201 * <P>
202 * A valid port value is between 0 and 65535.
203 * A port number of {@code zero} will let the system pick up an
204 * ephemeral port in a {@code bind} operation.
205 *
206 * @param hostname the Host name
207 * @param port The port number
208 * @throws IllegalArgumentException if the port parameter is outside the range
209 * of valid port values, or if the hostname parameter is {@code null}.
210 * @throws SecurityException if a security manager is present and
211 * permission to resolve the host name is
212 * denied.
213 * @see #isUnresolved()
214 */
215 public InetSocketAddress(String hostname, int port) {
216 checkHost(hostname);
217 InetAddress addr = null;
218 String host = null;
219 try {
220 addr = InetAddress.getByName(hostname);
221 } catch(UnknownHostException e) {
222 host = hostname;
223 }
224 holder = new InetSocketAddressHolder(host, addr, checkPort(port));
225 }
226
227 // private constructor for creating unresolved instances
228 private InetSocketAddress(int port, String hostname) {
229 holder = new InetSocketAddressHolder(hostname, null, port);
230 }
231
232 /**
233 *
234 * Creates an unresolved socket address from a hostname and a port number.
235 * <p>
236 * No attempt will be made to resolve the hostname into an InetAddress.
237 * The address will be flagged as <I>unresolved</I>.
238 * <p>
239 * A valid port value is between 0 and 65535.
240 * A port number of {@code zero} will let the system pick up an
241 * ephemeral port in a {@code bind} operation.
242 *
243 * @param host the Host name
244 * @param port The port number
245 * @throws IllegalArgumentException if the port parameter is outside
246 * the range of valid port values, or if the hostname
247 * parameter is {@code null}.
248 * @see #isUnresolved()
249 * @return an {@code InetSocketAddress} representing the unresolved
250 * socket address
251 * @since 1.5
252 */
253 public static InetSocketAddress createUnresolved(String host, int port) {
254 return new InetSocketAddress(checkPort(port), checkHost(host));
255 }
256
257 /**
258 * @serialField hostname String
259 * @serialField addr InetAddress
260 * @serialField port int
261 */
262 private static final ObjectStreamField[] serialPersistentFields = {
263 new ObjectStreamField("hostname", String.class),
264 new ObjectStreamField("addr", InetAddress.class),
265 new ObjectStreamField("port", int.class)};
266
267 private void writeObject(ObjectOutputStream out)
268 throws IOException
269 {
270 // Don't call defaultWriteObject()
271 ObjectOutputStream.PutField pfields = out.putFields();
272 pfields.put("hostname", holder.hostname);
273 pfields.put("addr", holder.addr);
274 pfields.put("port", holder.port);
275 out.writeFields();
276 }
277
278 private void readObject(ObjectInputStream in)
279 throws IOException, ClassNotFoundException
280 {
281 // Don't call defaultReadObject()
282 ObjectInputStream.GetField oisFields = in.readFields();
283 final String oisHostname = (String)oisFields.get("hostname", null);
284 final InetAddress oisAddr = (InetAddress)oisFields.get("addr", null);
285 final int oisPort = oisFields.get("port", -1);
286
287 // Check that our invariants are satisfied
288 checkPort(oisPort);
289 if (oisHostname == null && oisAddr == null)
290 throw new InvalidObjectException("hostname and addr " +
291 "can't both be null");
292
293 InetSocketAddressHolder h = new InetSocketAddressHolder(oisHostname,
294 oisAddr,
295 oisPort);
296 UNSAFE.putObject(this, FIELDS_OFFSET, h);
297 }
298
299 private void readObjectNoData()
300 throws ObjectStreamException
301 {
302 throw new InvalidObjectException("Stream data required");
303 }
304
305 private static final long FIELDS_OFFSET;
306 private static final jdk.internal.misc.Unsafe UNSAFE;
307 static {
308 jdk.internal.misc.Unsafe unsafe = jdk.internal.misc.Unsafe.getUnsafe();
309 FIELDS_OFFSET = unsafe.objectFieldOffset(InetSocketAddress.class, "holder");
310 UNSAFE = unsafe;
311 }
312
313 /**
314 * Gets the port number.
315 *
316 * @return the port number.
317 */
318 public final int getPort() {
319 return holder.getPort();
320 }
321
322 /**
323 *
324 * Gets the {@code InetAddress}.
325 *
326 * @return the InetAdress or {@code null} if it is unresolved.
327 */
328 public final InetAddress getAddress() {
329 return holder.getAddress();
330 }
331
332 /**
333 * Gets the {@code hostname}.
334 * Note: This method may trigger a name service reverse lookup if the
335 * address was created with a literal IP address.
336 *
337 * @return the hostname part of the address.
338 */
339 public final String getHostName() {
340 return holder.getHostName();
341 }
342
343 /**
344 * Returns the hostname, or the String form of the address if it
345 * doesn't have a hostname (it was created using a literal).
346 * This has the benefit of <b>not</b> attempting a reverse lookup.
347 *
348 * @return the hostname, or String representation of the address.
349 * @since 1.7
350 */
351 public final String getHostString() {
352 return holder.getHostString();
353 }
354
355 /**
356 * Checks whether the address has been resolved or not.
357 *
358 * @return {@code true} if the hostname couldn't be resolved into
359 * an {@code InetAddress}.
360 */
361 public final boolean isUnresolved() {
362 return holder.isUnresolved();
363 }
364
365 /**
366 * Constructs a string representation of this InetSocketAddress.
367 * This String is constructed by calling toString() on the InetAddress
368 * and concatenating the port number (with a colon). If the address
369 * is unresolved then the part before the colon will only contain the hostname.
370 *
371 * @return a string representation of this object.
372 */
373 @Override
374 public String toString() {
375 return holder.toString();
376 }
377
378 /**
379 * Compares this object against the specified object.
380 * The result is {@code true} if and only if the argument is
381 * not {@code null} and it represents the same address as
382 * this object.
383 * <p>
384 * Two instances of {@code InetSocketAddress} represent the same
385 * address if both the InetAddresses (or hostnames if it is unresolved) and port
386 * numbers are equal.
387 * If both addresses are unresolved, then the hostname and the port number
388 * are compared.
389 *
390 * Note: Hostnames are case insensitive. e.g. "FooBar" and "foobar" are
391 * considered equal.
392 *
393 * @param obj the object to compare against.
394 * @return {@code true} if the objects are the same;
395 * {@code false} otherwise.
396 * @see java.net.InetAddress#equals(java.lang.Object)
397 */
398 @Override
399 public final boolean equals(Object obj) {
400 if (obj == null || !(obj instanceof InetSocketAddress))
401 return false;
402 return holder.equals(((InetSocketAddress) obj).holder);
403 }
404
405 /**
406 * Returns a hashcode for this socket address.
407 *
408 * @return a hash code value for this socket address.
409 */
410 @Override
411 public final int hashCode() {
412 return holder.hashCode();
413 }
414 }