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20 package org.apache.mina.util;
21
22 import java.io.IOException;
23 import java.net.DatagramSocket;
24 import java.net.ServerSocket;
25 import java.util.NoSuchElementException;
26 import java.util.Set;
27 import java.util.TreeSet;
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35
36 public class AvailablePortFinder {
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40 public static final int MIN_PORT_NUMBER = 1;
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45 public static final int MAX_PORT_NUMBER = 49151;
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47
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49
50 private AvailablePortFinder() {
51 }
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60 public static Set<Integer> getAvailablePorts() {
61 return getAvailablePorts(MIN_PORT_NUMBER, MAX_PORT_NUMBER);
62 }
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68
69 public static int getNextAvailable() {
70 return getNextAvailable(MIN_PORT_NUMBER);
71 }
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78
79 public static int getNextAvailable(int fromPort) {
80 if (fromPort < MIN_PORT_NUMBER || fromPort > MAX_PORT_NUMBER) {
81 throw new IllegalArgumentException("Invalid start port: "
82 + fromPort);
83 }
84
85 for (int i = fromPort; i <= MAX_PORT_NUMBER; i++) {
86 if (available(i)) {
87 return i;
88 }
89 }
90
91 throw new NoSuchElementException("Could not find an available port "
92 + "above " + fromPort);
93 }
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99
100 public static boolean available(int port) {
101 if (port < MIN_PORT_NUMBER || port > MAX_PORT_NUMBER) {
102 throw new IllegalArgumentException("Invalid start port: " + port);
103 }
104
105 ServerSocket ss = null;
106 DatagramSocket ds = null;
107 try {
108 ss = new ServerSocket(port);
109 ss.setReuseAddress(true);
110 ds = new DatagramSocket(port);
111 ds.setReuseAddress(true);
112 return true;
113 } catch (IOException e) {
114 } finally {
115 if (ds != null) {
116 ds.close();
117 }
118
119 if (ss != null) {
120 try {
121 ss.close();
122 } catch (IOException e) {
123
124 }
125 }
126 }
127
128 return false;
129 }
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139 public static Set<Integer> getAvailablePorts(int fromPort, int toPort) {
140 if (fromPort < MIN_PORT_NUMBER || toPort > MAX_PORT_NUMBER
141 || fromPort > toPort) {
142 throw new IllegalArgumentException("Invalid port range: "
143 + fromPort + " ~ " + toPort);
144 }
145
146 Set<Integer> result = new TreeSet<Integer>();
147
148 for (int i = fromPort; i <= toPort; i++) {
149 ServerSocket s = null;
150
151 try {
152 s = new ServerSocket(i);
153 result.add(new Integer(i));
154 } catch (IOException e) {
155 } finally {
156 if (s != null) {
157 try {
158 s.close();
159 } catch (IOException e) {
160
161 }
162 }
163 }
164 }
165
166 return result;
167 }
168 }