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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 2000-2004 (C) Exoffice Technologies Inc. All Rights Reserved.
42   *
43   * $Id: MulticastCallerListener.java,v 1.2 2005/05/27 13:58:00 tanderson Exp $
44   */
45  package org.exolab.jms.net.connector;
46  
47  import java.util.ArrayList;
48  import java.util.Collections;
49  import java.util.HashMap;
50  import java.util.List;
51  import java.util.Map;
52  
53  import org.exolab.jms.net.uri.InvalidURIException;
54  import org.exolab.jms.net.uri.URI;
55  import org.exolab.jms.net.uri.URIHelper;
56  
57  
58  /***
59   * A listener for {@link Caller} events, which asynchronously propagates events
60   * to one or more registered listeners.
61   *
62   * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
63   * @version $Revision: 1.2 $ $Date: 2005/05/27 13:58:00 $
64   */
65  public class MulticastCallerListener implements CallerListener {
66  
67      /***
68       * The listeners. A set of <code>List</code> instances, keyed on
69       * URI.
70       */
71      private Map _listeners = Collections.synchronizedMap(new HashMap());
72  
73      /***
74       * Helper for casts.
75       */
76      private static final CallerListener[] EMPTY = new CallerListener[0];
77  
78  
79      /***
80       * Registers an event listener for caller events.
81       *
82       * @param uri      the remote URI to listen for events on
83       * @param listener the event listener
84       * @throws InvalidURIException if <code>uri</code> is invalid
85       */
86      public void addCallerListener(String uri, CallerListener listener)
87          throws InvalidURIException{
88          URI parsed = URIHelper.parse(uri);
89          parsed = URIHelper.convertHostToAddress(parsed);
90          List list = null;
91          synchronized (_listeners) {
92              list = (List) _listeners.get(parsed);
93              if (list == null) {
94                  list = Collections.synchronizedList(new ArrayList());
95                  _listeners.put(parsed, list);
96              }
97          }
98          list.add(listener);
99      }
100 
101     /***
102      * Removes an event listener for caller events.
103      *
104      * @param uri      the remote URI to remove the listener for
105      * @param listener the event listener to remove
106      * @throws InvalidURIException if <code>uri</code> is invalid
107      */
108     public void removeCallerListener(String uri, CallerListener listener)
109         throws InvalidURIException {
110         URI parsed = URIHelper.parse(uri);
111         parsed = URIHelper.convertHostToAddress(parsed);
112         List list = null;
113         synchronized (_listeners) {
114             list = (List) _listeners.get(parsed);
115             if (list != null) {
116                 list.remove(listener);
117             }
118         }
119     }
120 
121     /***
122      * Notifies that a connection has been disconnected.
123      *
124      * @param caller the caller that was disconnected
125      */
126     public void disconnected(Caller caller) {
127         CallerListener[] listeners = getListeners(caller.getRemoteURI());
128         for (int i = 0; i < listeners.length; ++i) {
129             listeners[i].disconnected(caller);
130         }
131     }
132 
133     /***
134      * Returns the registered listeners for a given URI.
135      *
136      * @param uri the URI to return the registered listsners for
137      * @return the registered listeners
138      */
139     private CallerListener[] getListeners(URI uri) {
140         CallerListener[] result = EMPTY;
141         List list = null;
142         synchronized (_listeners) {
143             list = (List) _listeners.get(uri);
144             if (list == null) {
145                 list = (List) _listeners.get(uri);
146             }
147         }
148         if (list != null) {
149             result = (CallerListener[]) list.toArray(EMPTY);
150         }
151         return result;
152     }
153 }