01: /*
02: * Copyright (c) 1998-2008 Caucho Technology -- all rights reserved
03: *
04: * This file is part of Resin(R) Open Source
05: *
06: * Each copy or derived work must preserve the copyright notice and this
07: * notice unmodified.
08: *
09: * Resin Open Source is free software; you can redistribute it and/or modify
10: * it under the terms of the GNU General Public License as published by
11: * the Free Software Foundation; either version 2 of the License, or
12: * (at your option) any later version.
13: *
14: * Resin Open Source is distributed in the hope that it will be useful,
15: * but WITHOUT ANY WARRANTY; without even the implied warranty of
16: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17: * of NON-INFRINGEMENT. See the GNU General Public License for more
18: * details.
19: *
20: * You should have received a copy of the GNU General Public License
21: * along with Resin Open Source; if not, write to the
22: *
23: * Free Software Foundation, Inc.
24: * 59 Temple Place, Suite 330
25: * Boston, MA 02111-1307 USA
26: *
27: * @author Scott Ferguson
28: */
29:
30: package com.caucho.jms.queue;
31:
32: import java.util.*;
33: import java.util.logging.*;
34:
35: import javax.jms.*;
36:
37: import com.caucho.jms.message.*;
38: import com.caucho.jms.connection.*;
39:
40: import com.caucho.config.types.Period;
41: import com.caucho.util.*;
42:
43: /**
44: * Implements an queue which polls the data periodically.
45: */
46: abstract public class PollingQueue extends AbstractQueue implements
47: AlarmListener {
48: private static final L10N L = new L10N(PollingQueue.class);
49: private static final Logger log = Logger
50: .getLogger(PollingQueue.class.getName());
51:
52: private long _pollPeriod = 10000;
53:
54: private boolean _isPolling;
55: private WeakAlarm _alarm;
56:
57: protected PollingQueue() {
58: _alarm = new WeakAlarm(this );
59: }
60:
61: public void setPollPeriod(Period period) {
62: _pollPeriod = period.getPeriod();
63: }
64:
65: protected void startPoll() {
66: _isPolling = true;
67: _alarm.queue(_pollPeriod);
68: }
69:
70: protected void stopPoll() {
71: _isPolling = false;
72: _alarm.dequeue();
73: }
74:
75: public void handleAlarm(Alarm alarm) {
76: try {
77: pollImpl();
78: } finally {
79: if (_isPolling)
80: _alarm.queue(_pollPeriod);
81: }
82: }
83:
84: protected void pollImpl() {
85: }
86: }
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