1   /**
2    * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3    *
4    * Permission is hereby granted, free of charge, to any person obtaining a copy
5    * of this software and associated documentation files (the "Software"), to deal
6    * in the Software without restriction, including without limitation the rights
7    * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8    * copies of the Software, and to permit persons to whom the Software is
9    * furnished to do so, subject to the following conditions:
10   *
11   * The above copyright notice and this permission notice shall be included in
12   * all copies or substantial portions of the Software.
13   *
14   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20   * SOFTWARE.
21   */
22  
23  package com.liferay.portal.kernel.messaging;
24  
25  import com.liferay.portal.kernel.log.Log;
26  import com.liferay.portal.kernel.log.LogFactoryUtil;
27  import com.liferay.portal.kernel.util.ListUtil;
28  
29  import java.util.Arrays;
30  import java.util.HashSet;
31  import java.util.List;
32  import java.util.Set;
33  import java.util.concurrent.ThreadPoolExecutor;
34  
35  /**
36   * <a href="ArrayDispatcherDestination.java.html"><b><i>View Source</i></b></a>
37   *
38   * @author Michael C. Han
39   * @author Brian Wing Shun Chan
40   *
41   */
42  public abstract class ArrayDispatcherDestination extends BaseDestination {
43  
44      public ArrayDispatcherDestination(String name) {
45          super(name);
46      }
47  
48      public ArrayDispatcherDestination(
49          String name, int workersCoreSize, int workersMaxSize) {
50  
51          super(name, workersCoreSize, workersMaxSize);
52      }
53  
54      public synchronized void register(MessageListener listener) {
55          listener = new InvokerMessageListener(listener);
56  
57          Set<MessageListener> listeners = new HashSet<MessageListener>(
58              Arrays.asList(_listeners));
59  
60          listeners.add(listener);
61  
62          _listeners = listeners.toArray(
63              new MessageListener[listeners.size()]);
64  
65          setListenersCount(listeners.size());
66      }
67  
68      public void send(Message message) {
69          if (_listeners.length == 0) {
70              if (_log.isDebugEnabled()) {
71                  _log.debug("No listeners for destination " + getName());
72              }
73  
74              return;
75          }
76  
77          ThreadPoolExecutor threadPoolExecutor = getThreadPoolExecutor();
78  
79          if (threadPoolExecutor.isShutdown()) {
80              throw new IllegalStateException(
81                  "Destination " + getName() + " is shutdown and cannot " +
82                      "receive more messages");
83          }
84  
85          dispatch(_listeners, message);
86      }
87  
88      public synchronized boolean unregister(MessageListener listener) {
89          listener = new InvokerMessageListener(listener);
90  
91          List<MessageListener> listeners = ListUtil.fromArray(_listeners);
92  
93          boolean value = listeners.remove(listener);
94  
95          if (value) {
96              _listeners = listeners.toArray(
97                  new MessageListener[listeners.size()]);
98  
99              setListenersCount(listeners.size());
100         }
101 
102         return value;
103     }
104 
105     protected abstract void dispatch(
106         MessageListener[] listeners, Message message);
107 
108     private static Log _log = LogFactoryUtil.getLog(BaseDestination.class);
109 
110     private MessageListener[] _listeners = new MessageListener[0];
111 
112 }