01: /*
02: * JBoss, Home of Professional Open Source.
03: * Copyright 2006, Red Hat Middleware LLC, and individual contributors
04: * as indicated by the @author tags. See the copyright.txt file in the
05: * distribution for a full listing of individual contributors.
06: *
07: * This is free software; you can redistribute it and/or modify it
08: * under the terms of the GNU Lesser General Public License as
09: * published by the Free Software Foundation; either version 2.1 of
10: * the License, or (at your option) any later version.
11: *
12: * This software is distributed in the hope that it will be useful,
13: * but WITHOUT ANY WARRANTY; without even the implied warranty of
14: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15: * Lesser General Public License for more details.
16: *
17: * You should have received a copy of the GNU Lesser General Public
18: * License along with this software; if not, write to the Free
19: * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20: * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
21: */
22: package org.jboss.messaging.channel.plugins.handler;
23:
24: import org.jboss.messaging.interfaces.*;
25: import org.jboss.messaging.interfaces.Consumer;
26: import org.jboss.messaging.interfaces.MessageReference;
27:
28: /**
29: * A channel handler that has only one consumer
30: *
31: * @author <a href="mailto:adrian@jboss.org">Adrian Brock</a>
32: * @version $Revision: 57195 $
33: */
34: public class ExclusiveChannelHandler extends AbstractChannelHandler {
35: // Constants -----------------------------------------------------
36:
37: // Attributes ----------------------------------------------------
38:
39: /** Set when the consumer is waiting for a message */
40: private Consumer consumer;
41:
42: // Static --------------------------------------------------------
43:
44: // Constructors --------------------------------------------------
45:
46: /**
47: * Create a new ExclusiveChannelHandler.
48: *
49: * @param messages the message set
50: */
51: public ExclusiveChannelHandler(MessageSet messages) {
52: super (messages);
53: }
54:
55: // Public --------------------------------------------------------
56:
57: // AbstractChannelHandler overrides ------------------------------
58:
59: protected void addConsumer(Consumer consumer, long wait) {
60: this .consumer = consumer;
61: }
62:
63: protected Consumer findConsumer(MessageReference reference) {
64: // The messages are checked at addition to the channel
65: if (consumer != null) {
66: Consumer result = consumer;
67: consumer = null;
68: return result;
69: }
70: return null;
71: }
72:
73: protected void removeConsumer(Consumer consumer) {
74: consumer = null;
75: }
76:
77: // Protected -----------------------------------------------------
78:
79: // Package Private -----------------------------------------------
80:
81: // Private -------------------------------------------------------
82:
83: // Inner Classes -------------------------------------------------
84: }
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