-
Notifications
You must be signed in to change notification settings - Fork 628
/
SocketUtils.java
395 lines (364 loc) · 11.9 KB
/
SocketUtils.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
/*
* Copyright (c) 2011-2022 VMware, Inc. or its affiliates, All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package reactor.netty;
import java.net.DatagramSocket;
import java.net.ServerSocket;
import java.util.Random;
import java.util.SortedSet;
import java.util.TreeSet;
import javax.net.ServerSocketFactory;
/**
* NOTE: This code is a copy of that available in the Spring Framework.
*
* <p>Simple utility methods for working with network sockets — for example,
* for finding available ports on {@code localhost}.</p>
*
* <p>Within this class, a TCP port refers to a port for a {@link ServerSocket};
* whereas, a UDP port refers to a port for a {@link DatagramSocket}.</p>
*
* @author Sam Brannen
* @author Ben Hale
* @author Arjen Poutsma
* @author Gunnar Hillert
* @see <a href="https://spring.io">Borrowed from the Spring Framework</a>
* */
public final class SocketUtils {
/**
* The default minimum value for port ranges used when finding an available
* socket port.
*/
public static final int PORT_RANGE_MIN = 1024;
/**
* The default maximum value for port ranges used when finding an available
* socket port.
*/
public static final int PORT_RANGE_MAX = 65535;
private static final Random random = new Random(System.currentTimeMillis());
/**
* Although {@code SocketUtils} consists solely of static utility methods,
* this constructor is intentionally {@code public}.
*
* <h4>Rationale</h4>
*
* <p>Static methods from this class may be invoked from within XML
* configuration files using the Spring Expression Language (SpEL) and the
* following syntax.
*
* <pre><code><bean id="bean1" ... p:port="#{T(org.springframework.util.SocketUtils).findAvailableTcpPort(12000)}"
* /></code></pre>
*
* If this constructor were {@code private}, you would be required to supply
* the fully qualified class name to SpEL's {@code T()} function for each usage.
* Thus, the fact that this constructor is {@code public} allows you to reduce
* boilerplate configuration with SpEL as can be seen in the following example.
*
* <pre><code><bean id="socketUtils" class="org.springframework.util.SocketUtils" />
*
* <bean id="bean1" ... p:port="#{socketUtils.findAvailableTcpPort(12000)}" />
*
* <bean id="bean2" ... p:port="#{socketUtils.findAvailableTcpPort(30000)}" /></code></pre>
*/
public SocketUtils() {
/* no-op */
}
/**
* Find an available TCP port randomly selected from the range
* [{@value #PORT_RANGE_MIN}, {@value #PORT_RANGE_MAX}].
*
* @return an available TCP port number
*
* @throws IllegalStateException
* if no available port could be found
*/
public static int findAvailableTcpPort() {
return findAvailableTcpPort(PORT_RANGE_MIN);
}
/**
* Find an available TCP port randomly selected from the range
* [{@code minPort}, {@value #PORT_RANGE_MAX}].
*
* @param minPort
* the minimum port number
*
* @return an available TCP port number
*
* @throws IllegalStateException
* if no available port could be found
*/
public static int findAvailableTcpPort(int minPort) {
return findAvailableTcpPort(minPort, PORT_RANGE_MAX);
}
/**
* Find an available TCP port randomly selected from the range
* [{@code minPort}, {@code maxPort}].
*
* @param minPort
* the minimum port number
* @param maxPort
* the maximum port number
*
* @return an available TCP port number
*
* @throws IllegalStateException
* if no available port could be found
*/
public static int findAvailableTcpPort(int minPort, int maxPort) {
return SocketType.TCP.findAvailablePort(minPort, maxPort);
}
/**
* Find the requested number of available TCP ports, each randomly selected
* from the range [{@value #PORT_RANGE_MIN}, {@value #PORT_RANGE_MAX}].
*
* @param numRequested
* the number of available ports to find
*
* @return a sorted set of available TCP port numbers
*
* @throws IllegalStateException
* if the requested number of available ports could not be found
*/
public static SortedSet<Integer> findAvailableTcpPorts(int numRequested) {
return findAvailableTcpPorts(numRequested, PORT_RANGE_MIN, PORT_RANGE_MAX);
}
/**
* Find the requested number of available TCP ports, each randomly selected
* from the range [{@code minPort}, {@code maxPort}].
*
* @param numRequested
* the number of available ports to find
* @param minPort
* the minimum port number
* @param maxPort
* the maximum port number
*
* @return a sorted set of available TCP port numbers
*
* @throws IllegalStateException
* if the requested number of available ports could not be found
*/
public static SortedSet<Integer> findAvailableTcpPorts(int numRequested, int minPort, int maxPort) {
return SocketType.TCP.findAvailablePorts(numRequested, minPort, maxPort);
}
/**
* Find an available UDP port randomly selected from the range
* [{@value #PORT_RANGE_MIN}, {@value #PORT_RANGE_MAX}].
*
* @return an available UDP port number
*
* @throws IllegalStateException
* if no available port could be found
*/
public static int findAvailableUdpPort() {
return findAvailableUdpPort(PORT_RANGE_MIN);
}
/**
* Find an available UDP port randomly selected from the range
* [{@code minPort}, {@value #PORT_RANGE_MAX}].
*
* @param minPort
* the minimum port number
*
* @return an available UDP port number
*
* @throws IllegalStateException
* if no available port could be found
*/
public static int findAvailableUdpPort(int minPort) {
return findAvailableUdpPort(minPort, PORT_RANGE_MAX);
}
/**
* Find an available UDP port randomly selected from the range
* [{@code minPort}, {@code maxPort}].
*
* @param minPort
* the minimum port number
* @param maxPort
* the maximum port number
*
* @return an available UDP port number
*
* @throws IllegalStateException
* if no available port could be found
*/
public static int findAvailableUdpPort(int minPort, int maxPort) {
return SocketType.UDP.findAvailablePort(minPort, maxPort);
}
/**
* Find the requested number of available UDP ports, each randomly selected
* from the range [{@value #PORT_RANGE_MIN}, {@value #PORT_RANGE_MAX}].
*
* @param numRequested
* the number of available ports to find
*
* @return a sorted set of available UDP port numbers
*
* @throws IllegalStateException
* if the requested number of available ports could not be found
*/
public static SortedSet<Integer> findAvailableUdpPorts(int numRequested) {
return findAvailableUdpPorts(numRequested, PORT_RANGE_MIN, PORT_RANGE_MAX);
}
/**
* Find the requested number of available UDP ports, each randomly selected
* from the range [{@code minPort}, {@code maxPort}].
*
* @param numRequested
* the number of available ports to find
* @param minPort
* the minimum port number
* @param maxPort
* the maximum port number
*
* @return a sorted set of available UDP port numbers
*
* @throws IllegalStateException
* if the requested number of available ports could not be found
*/
public static SortedSet<Integer> findAvailableUdpPorts(int numRequested, int minPort, int maxPort) {
return SocketType.UDP.findAvailablePorts(numRequested, minPort, maxPort);
}
private enum SocketType {
TCP {
@Override
protected boolean isPortAvailable(int port) {
try {
ServerSocket serverSocket = ServerSocketFactory.getDefault().createServerSocket(port);
serverSocket.close();
return true;
}
catch (Exception ex) {
return false;
}
}
},
UDP {
@Override
protected boolean isPortAvailable(int port) {
try {
DatagramSocket socket = new DatagramSocket(port);
socket.close();
return true;
}
catch (Exception ex) {
return false;
}
}
};
/**
* Determine if the specified port for this {@code SocketType} is
* currently available on {@code localhost}.
*/
protected abstract boolean isPortAvailable(int port);
/**
* Find a pseudo-random port number within the range
* [{@code minPort}, {@code maxPort}].
*
* @param minPort
* the minimum port number
* @param maxPort
* the maximum port number
*
* @return a random port number within the specified range
*/
private int findRandomPort(int minPort, int maxPort) {
int portRange = maxPort - minPort;
return minPort + random.nextInt(portRange);
}
/**
* Find an available port for this {@code SocketType}, randomly selected
* from the range [{@code minPort}, {@code maxPort}].
*
* @param minPort
* the minimum port number
* @param maxPort
* the maximum port number
*
* @return an available port number for this socket type
*
* @throws IllegalStateException
* if no available port could be found
*/
int findAvailablePort(int minPort, int maxPort) {
if (minPort <= 0) {
throw new IllegalArgumentException("'minPort' must be greater than 0");
}
else if (minPort > maxPort) {
throw new IllegalArgumentException("'maxPort' must be greater than 'minPort'");
}
else if (maxPort > PORT_RANGE_MAX) {
throw new IllegalArgumentException("'maxPort' must be less than or equal to " + PORT_RANGE_MAX);
}
int portRange = maxPort - minPort;
int candidatePort;
int searchCounter = 0;
do {
if (++searchCounter > portRange) {
throw new IllegalStateException(String.format(
"Could not find an available %s port in the range [%d, %d] after %d attempts", name(), minPort,
maxPort, searchCounter));
}
candidatePort = findRandomPort(minPort, maxPort);
} while (!isPortAvailable(candidatePort));
return candidatePort;
}
/**
* Find the requested number of available ports for this {@code SocketType},
* each randomly selected from the range [{@code minPort}, {@code maxPort}].
*
* @param numRequested
* the number of available ports to find
* @param minPort
* the minimum port number
* @param maxPort
* the maximum port number
*
* @return a sorted set of available port numbers for this socket type
*
* @throws IllegalStateException
* if the requested number of available ports could not be found
*/
SortedSet<Integer> findAvailablePorts(int numRequested, int minPort, int maxPort) {
if (minPort <= 0) {
throw new IllegalArgumentException("'minPort' must be greater than 0");
}
else if (minPort > maxPort) {
throw new IllegalArgumentException("'maxPort' must be greater than 'minPort'");
}
else if (maxPort > PORT_RANGE_MAX) {
throw new IllegalArgumentException("'maxPort' must be less than or equal to " + PORT_RANGE_MAX);
}
else if (numRequested <= 0) {
throw new IllegalArgumentException("'numRequested' must be greater than 0");
}
else if ((maxPort - minPort) < numRequested) {
throw new IllegalArgumentException("'numRequested' must not be greater than 'maxPort' - 'minPort'");
}
final TreeSet<Integer> availablePorts = new TreeSet<>();
int attemptCount = 0;
//CHECKSTYLE:OFF
// "Unnecessary parentheses around expression"
while ((++attemptCount <= numRequested + 100) && (availablePorts.size() < numRequested)) { //CHECKSTYLE:ON
availablePorts.add(findAvailablePort(minPort, maxPort));
}
if (availablePorts.size() != numRequested) {
throw new IllegalStateException(String.format(
"Could not find %d available %s ports in the range [%d, %d]", numRequested, name(), minPort,
maxPort));
}
return availablePorts;
}
}
}