1 /***
2 * Redistribution and use of this software and associated documentation
3 * ("Software"), with or without modification, are permitted provided
4 * that the following conditions are met:
5 *
6 * 1. Redistributions of source code must retain copyright
7 * statements and notices. Redistributions must also contain a
8 * copy of this document.
9 *
10 * 2. Redistributions in binary form must reproduce the
11 * above copyright notice, this list of conditions and the
12 * following disclaimer in the documentation and/or other
13 * materials provided with the distribution.
14 *
15 * 3. The name "Exolab" must not be used to endorse or promote
16 * products derived from this Software without prior written
17 * permission of Exoffice Technologies. For written permission,
18 * please contact info@exolab.org.
19 *
20 * 4. Products derived from this Software may not be called "Exolab"
21 * nor may "Exolab" appear in their names without prior written
22 * permission of Exoffice Technologies. Exolab is a registered
23 * trademark of Exoffice Technologies.
24 *
25 * 5. Due credit should be given to the Exolab Project
26 * (http://www.exolab.org/).
27 *
28 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
30 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
31 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
32 * EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
33 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
37 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39 * OF THE POSSIBILITY OF SUCH DAMAGE.
40 *
41 * Copyright 2004-2005 (C) Exoffice Technologies Inc. All Rights Reserved.
42 *
43 * $Id: ConnectionContext.java,v 1.5 2005/12/01 13:44:38 tanderson Exp $
44 */
45 package org.exolab.jms.net.connector;
46
47 import java.security.Principal;
48 import java.util.ArrayList;
49 import java.util.List;
50
51 import org.apache.commons.logging.Log;
52 import org.apache.commons.logging.LogFactory;
53
54 import org.exolab.jms.net.uri.URI;
55
56
57 /***
58 * <code>ConnectionContext</code> enables connectors to associate a {@link
59 * Connection} and {@link ConnectionFactory} with th current thread, to enable
60 * deserialized {@link org.exolab.jms.net.proxy.Proxy} instances to resolve a
61 * {@link Connection} back to the server.
62 *
63 * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
64 * @version $Revision: 1.5 $ $Date: 2005/12/01 13:44:38 $
65 */
66 public final class ConnectionContext {
67
68 /***
69 * Maintains a List of {@link Context} instances on a per-thread basis.
70 */
71 private static ThreadLocal _contexts = new ThreadLocal();
72
73 /***
74 * The logger.
75 */
76 private static final Log _log = LogFactory.getLog(ConnectionContext.class);
77
78
79 /***
80 * Prevent construction of helper class.
81 */
82 private ConnectionContext() {
83 }
84
85 /***
86 * Adds the connection context for the current thread.
87 *
88 * @param principal the security principal
89 * @param factory the connection factory
90 */
91 public static void push(Principal principal, ConnectionFactory factory) {
92 List stack = (List) _contexts.get();
93 if (stack == null) {
94 stack = new ArrayList(2);
95 _contexts.set(stack);
96 }
97 stack.add(new Context(principal, factory));
98 }
99
100 /***
101 * Removes the last-pushed context for the current thread.
102 */
103 public static void pop() {
104 List stack = (List) _contexts.get();
105 stack.remove(stack.size() - 1);
106 }
107
108 /***
109 * Returns a connection using the principal and connection factory
110 * associated with the current thread.
111 *
112 * @param uri the URI
113 * @return a new connection, or <code>null</code> if a connection can't
114 * be established
115 */
116 public static Connection getConnection(URI uri) {
117 Connection result = null;
118 Context context = top();
119 if (context != null) {
120 ConnectionFactory factory = context.getConnectionFactory();
121 try {
122 result = factory.getConnection(context.getPrincipal(), uri);
123 } catch (ResourceException exception) {
124 _log.debug(exception, exception);
125 }
126 }
127 return result;
128 }
129
130 /***
131 * Returns the connection factory for the current thread.
132 *
133 * @return the connection factory for the current thread, or
134 * <code>null</code> if no factory is set
135 */
136 public static ConnectionFactory getConnectionFactory() {
137 ConnectionFactory result = null;
138 Context context = top();
139 if (context != null) {
140 result = context.getConnectionFactory();
141 }
142 return result;
143 }
144
145 /***
146 * Returns the context at the top of the local threads stack.
147 *
148 * @return the top context, or <code>null</code> if there are no contexts
149 * associated with this thread.
150 */
151 private static Context top() {
152 Context context = null;
153 List stack = (List) _contexts.get();
154 if (stack != null && !stack.isEmpty()) {
155 context = (Context) stack.get(stack.size() - 1);
156 }
157 return context;
158 }
159
160
161 private static class Context {
162
163 /***
164 * The security principal.
165 */
166 private final Principal _principal;
167
168 /***
169 * The connection factory.
170 */
171 private final ConnectionFactory _factory;
172
173
174 /***
175 * Construct a new <code>Context</code>.
176 *
177 * @param principal the security principal
178 * @param factory the connection factory
179 */
180 public Context(Principal principal, ConnectionFactory factory) {
181 _principal = principal;
182 _factory = factory;
183 }
184
185 /***
186 * Returns the security principal.
187 *
188 * @return the security principal
189 */
190 public Principal getPrincipal() {
191 return _principal;
192 }
193
194 /***
195 * Returns the connection factory.
196 *
197 * @return the connection factory.
198 */
199 public ConnectionFactory getConnectionFactory() {
200 return _factory;
201 }
202
203 }
204 }