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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 2003-2005 (C) Exoffice Technologies Inc. All Rights Reserved.
42   *
43   * $Id: ObjectRef.java,v 1.2 2005/11/16 12:32:49 tanderson Exp $
44   */
45  package org.exolab.jms.net.orb;
46  
47  import java.lang.reflect.Constructor;
48  import java.lang.reflect.InvocationTargetException;
49  import java.rmi.NoSuchObjectException;
50  import java.rmi.server.ExportException;
51  import java.rmi.server.ObjID;
52  import java.util.HashMap;
53  
54  import org.exolab.jms.net.proxy.Delegate;
55  import org.exolab.jms.net.proxy.Proxy;
56  import org.exolab.jms.net.uri.URI;
57  
58  
59  /***
60   * Maintains state information for an exported object.
61   *
62   * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
63   * @version $Revision: 1.2 $ $Date: 2005/11/16 12:32:49 $
64   */
65  class ObjectRef {
66  
67      /***
68       * The identity of the object.
69       */
70      private ObjID _objID;
71  
72      /***
73       * The exported object.
74       */
75      private Object _object;
76  
77      /***
78       * The proxy class of the exported object, implementing the {@link Proxy}
79       * interface.
80       */
81      private Class _proxyClass;
82  
83      /***
84       * The set of {@link UnicastDelegate} instances, keyed on URI.
85       */
86      private HashMap _proxies = new HashMap();
87  
88      /***
89       * Helper for Proxy constructor resolution.
90       */
91      private static final Class[] PROXY_ARGS = new Class[]{Delegate.class};
92  
93      /***
94       * Construct a new <code>ObjectRef</code>.
95       *
96       * @param objID      the object identity
97       * @param object     the exported object
98       * @param proxyClass the proxy class of the exported object, implementing
99       *                   the {@link Proxy} interface
100      */
101     public ObjectRef(ObjID objID, Object object, Class proxyClass) {
102         _objID = objID;
103         _object = object;
104         _proxyClass = proxyClass;
105     }
106 
107     /***
108      * Returns the identity of the exported object.
109      *
110      * @return the object identity
111      */
112     public ObjID getObjID() {
113         return _objID;
114     }
115 
116     /***
117      * Returns the exported object.
118      *
119      * @return the exported object
120      */
121     public Object getObject() {
122         return _object;
123     }
124 
125     /***
126      * Returns the proxy class of the exported object. This implements the
127      * {@link Proxy} interface.
128      *
129      * @return the proxy class
130      */
131     public Class getProxyClass() {
132         return _proxyClass;
133     }
134 
135     /***
136      * Add a proxy for the object.
137      *
138      * @param uri the connection URI
139      * @return a proxy for the object
140      * @throws ExportException if the proxy can't be constructed
141      */
142     public synchronized Proxy addProxy(URI uri) throws ExportException {
143         Proxy proxy;
144         try {
145             Delegate delegate = new UnicastDelegate(_objID, uri.toString());
146             Constructor constructor = _proxyClass.getConstructor(PROXY_ARGS);
147             proxy = (Proxy) constructor.newInstance(new Object[]{delegate});
148         } catch (InvocationTargetException exception) {
149             if (exception.getTargetException() instanceof Exception) {
150                 Exception nested = (Exception) exception.getTargetException();
151                 throw new ExportException(nested.getMessage(), nested);
152             } else {
153                 throw new ExportException(exception.getMessage(), exception);
154             }
155         } catch (Exception exception) {
156             throw new ExportException(exception.getMessage(), exception);
157         }
158         _proxies.put(uri, proxy);
159         return proxy;
160     }
161 
162     /***
163      * Returns the proxy for the specified URI.
164      *
165      * @param uri the connection URI
166      * @return a proxy for the object
167      * @throws NoSuchObjectException if the object isn't exported on the
168      *                               specified URI
169      */
170     public synchronized Proxy getProxy(URI uri)
171             throws NoSuchObjectException {
172 
173         Proxy proxy = (Proxy) _proxies.get(uri);
174         if (proxy == null) {
175             throw new NoSuchObjectException(
176                     "Object not exported on URI=" + uri);
177         }
178         return proxy;
179     }
180 
181     /***
182      * Returns a list of URIs that the object is exported on.
183      *
184      * @return a list of URIs that the object is exported on
185      */
186     public synchronized URI[] getURIs() {
187         return (URI[]) _proxies.keySet().toArray(new URI[0]);
188     }
189 
190     /***
191      * Determines if this equals another object.
192      *
193      * @param object the object to compare
194      * @return <code>true</code> if this is equal, otherwise <code>false</code>
195      */
196     public boolean equals(Object object) {
197         boolean equal = (this == object);
198         if (!equal && (object instanceof ObjectRef)) {
199             equal = _objID.equals(((ObjectRef) object)._objID);
200         }
201         return equal;
202     }
203 
204     /***
205      * Returns the hash code of this.
206      *
207      * @return the hash code of this
208      */
209     public int hashCode() {
210         return _objID.hashCode();
211     }
212 
213 }