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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 2003-2004 (C) Exoffice Technologies Inc. All Rights Reserved.
42   *
43   * $Id: RegistryImpl.java,v 1.1 2004/11/26 01:51:04 tanderson Exp $
44   */
45  package org.exolab.jms.net.orb;
46  
47  import java.rmi.AccessException;
48  import java.rmi.AlreadyBoundException;
49  import java.rmi.NotBoundException;
50  import java.util.HashMap;
51  
52  import org.exolab.jms.net.proxy.Proxy;
53  import org.exolab.jms.net.registry.Registry;
54  
55  
56  /***
57   * The <code>RegistryImpl</code> provides a simple interface for binding and
58   * retrieving remote object references by name.
59   *
60   * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
61   * @version $Revision: 1.1 $ $Date: 2004/11/26 01:51:04 $
62   */
63  class RegistryImpl implements Registry {
64  
65      /***
66       * The registry service proxy class name
67       */
68      public static final String PROXY =
69              RegistryImpl.class.getName() + "__Proxy";
70  
71      /***
72       * A map of bindings to proxies
73       */
74      private HashMap _registry = new HashMap();
75  
76      /***
77       * Determines if the registry is read-only for remote users
78       */
79      private boolean _readOnly = false;
80  
81  
82      /***
83       * Construct a new <code>RegistryImpl</code>
84       */
85      public RegistryImpl() {
86      }
87  
88      /***
89       * Returns a proxy for the remote object associated with the specified name
90       *
91       * @param name the name the proxy is bound under
92       * @return proxy the proxy for the remote object
93       * @throws NotBoundException if <code>name<code> is not bound
94       */
95      public synchronized Proxy lookup(String name) throws NotBoundException {
96          Proxy proxy = (Proxy) _registry.get(name);
97          if (proxy == null) {
98              throw new NotBoundException(name);
99          }
100         return proxy;
101     }
102 
103     /***
104      * Binds the specified name to a remote object.
105      *
106      * @param name  the name of the binding
107      * @param proxy the proxy for the remote object
108      * @throws AccessException       if the caller doesn't have permission to
109      *                               bind the object
110      * @throws AlreadyBoundException if <code>name</code> is already bound
111      */
112     public synchronized void bind(String name, Proxy proxy)
113             throws AccessException, AlreadyBoundException {
114         checkReadOnly();
115         doBind(name, proxy);
116     }
117 
118     /***
119      * Removes the binding for the specified name
120      *
121      * @param name the name of the binding
122      * @throws AccessException   if the caller doesn't have permission to unbind
123      *                           the object
124      * @throws NotBoundException if <code>name<code> is not bound
125      */
126     public synchronized void unbind(String name)
127             throws AccessException, NotBoundException {
128         checkReadOnly();
129         doUnbind(name);
130     }
131 
132     /***
133      * Binds the specified name to a remote object.
134      *
135      * @param name  the name of the binding
136      * @param proxy the proxy for the remote object
137      * @throws AlreadyBoundException if <code>name</code> is already bound
138      */
139     protected synchronized void doBind(String name, Proxy proxy)
140             throws AlreadyBoundException {
141         if (_registry.containsKey(name)) {
142             throw new AlreadyBoundException(name);
143         }
144         _registry.put(name, proxy);
145     }
146 
147     /***
148      * Removes the binding for the specified name
149      *
150      * @param name the name of the binding
151      * @throws NotBoundException if <code>name<code> is not bound
152      */
153     protected synchronized void doUnbind(String name)
154             throws NotBoundException {
155         Object proxy = _registry.remove(name);
156         if (proxy == null) {
157             throw new NotBoundException(name);
158         }
159     }
160 
161     /***
162      * Set if the registry is read-only
163      *
164      * @param readOnly if <code>true</code>, prevent remote users from modifying
165      *                 bindings
166      */
167     protected synchronized void setReadOnly(boolean readOnly) {
168         _readOnly = readOnly;
169     }
170 
171     /***
172      * Determines if the registry is read-only
173      *
174      * @return <code>true</code> if the registry is read-only
175      */
176     protected synchronized boolean getReadOnly() {
177         return _readOnly;
178     }
179 
180     /***
181      * Checks if the registry is read-only
182      *
183      * @throws AccessException if the registry is read-only
184      */
185     private void checkReadOnly() throws AccessException {
186         if (_readOnly) {
187             throw new AccessException("Registry is read-only");
188         }
189     }
190 
191 }