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1 package org.sapia.ubik.net;
2
3 import java.io.*;
4
5 import java.rmi.server.RMIClientSocketFactory  ;
6
7 import java.util.*;
8
9
10
16 public class ConnectionPool {
17 public static final long DEFAULT_ACQUIRE_TIME_OUT = 2000;
18 private Vector _conns = new Vector(50);
19 protected ConnectionFactory _fac;
20 protected String _host;
21 protected int _port;
22 protected int _maxSize;
23 protected int _currentCount;
24 protected long _lastUsageTime = System.currentTimeMillis();
25 protected RMIClientSocketFactory _socketFactory;
26
27 public ConnectionPool(String host, int port, ConnectionFactory fac,
28 RMIClientSocketFactory socketFactory) {
29 _fac = fac;
30 _host = host;
31 _port = port;
32 _socketFactory = socketFactory;
33 }
34
35 public ConnectionPool(String host, int port, ConnectionFactory fac,
36 RMIClientSocketFactory socketFactory, int maxSize) {
37 this(host, port, fac, socketFactory);
38 _maxSize = maxSize;
39 }
40
41 public ConnectionPool(String host, int port,
42 RMIClientSocketFactory socketFactory) {
43 this(host, port, new SocketConnectionFactory(), socketFactory);
44 }
45
46 public ConnectionPool(String host, int port, int maxSize,
47 RMIClientSocketFactory socketFactory) {
48 this(host, port, new SocketConnectionFactory(), socketFactory, maxSize);
49 }
50
51 public synchronized Connection acquire() throws IOException {
52 return acquire(DEFAULT_ACQUIRE_TIME_OUT);
53 }
54
55 public synchronized Connection acquire(long timeout)
56 throws IOException {
57 Connection conn;
58
59 if (_conns.size() == 0) {
60 if (_maxSize <= 0) {
61 conn = newConnection();
62 } else {
63 if (_conns.size() == 0) {
64 try {
65 if (timeout > 0) {
66 wait(timeout);
67 }
68 } catch (InterruptedException e) {
69 throw new IOException("thread interrupted");
70 }
71
72 if (_currentCount >= _maxSize) {
73 throw new IOException("maximum connection pool size reached");
74 } else {
75 conn = newConnection();
76 }
77 } else {
78 conn = (Connection) _conns.remove(0);
79 }
80 }
81 } else {
82 conn = (Connection) _conns.remove(0);
83 }
84
85 return conn;
86 }
87
88 public synchronized void release(Connection conn) {
89 _lastUsageTime = System.currentTimeMillis();
90 _conns.add(conn);
91 notify();
92 }
93
94 public synchronized int getCount() {
95 return _currentCount;
96 }
97
98
102 public long getLastUsageTime() {
103 return _lastUsageTime;
104 }
105
106
112 public synchronized void shrinkTo(int size) {
113 while ((_conns.size() > size) && (_conns.size() > 0)) {
114 _currentCount--;
115
116 if (_currentCount < 0) {
117 _currentCount = 0;
118 }
119
120 Connection conn = (Connection) _conns.remove(0);
121 conn.close();
122 }
123 }
124
125 protected Connection newConnection() throws IOException {
126 _currentCount++;
127
128 return _fac.newConnection(_host, _port);
129 }
130 }
131 |
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