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 2005 (C) Exoffice Technologies Inc. All Rights Reserved.
42 *
43 * $Id: TimedCondition.java,v 1.1 2005/08/30 06:23:11 tanderson Exp $
44 */
45 package org.exolab.jms.messagemgr;
46
47
48 /***
49 * A timed {@link Condition}.
50 *
51 * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
52 * @version $Revision: 1.1 $ $Date: 2005/08/30 06:23:11 $
53 */
54 public class TimedCondition implements Condition {
55
56 /***
57 * The absolute time, in millseconds.
58 */
59 private final long _time;
60
61 /***
62 * Determines if the condition evaluates <code>true</code> while before or
63 * after <code>time</code>.
64 */
65 private final boolean _before;
66
67
68 /***
69 * Construct a new <code>TimedCondition</code>.
70 *
71 * @param time the absolute time, in milliseconds
72 * @param before determines if the condition evaluates <code>true</code>
73 * while before or after <code>time</code>.
74 */
75 private TimedCondition(long time, boolean before) {
76 _time = time;
77 _before = before;
78 }
79
80 /***
81 * Evaluates the condition.
82 *
83 * @return the value of the condition
84 */
85 public boolean get() {
86 final long current = System.currentTimeMillis();
87 if (_before) {
88 return current < _time;
89 }
90 return current >= _time;
91 }
92
93 /***
94 * Create a new <code>TimedCondition</code> that evaluates <code>true</code>
95 * while the current time < Now + time
96 *
97 * @param time the relative time, in milliseconds
98 * @return a condition that evaluates <code>true</code> while the current
99 * time < Now + time
100 */
101 public static Condition before(long time) {
102 return new TimedCondition(getAbsTime(time), true);
103 }
104
105 /***
106 * Create a new <code>TimedCondition</code> that evaluates <code>true</code>
107 * while the current time >= Now + time
108 *
109 * @param time the relative time, in milliseconds
110 * @return a condition that evaluates <code>true</code> while the current
111 * time >= Now + time
112 */
113 public static Condition after(long time) {
114 return new TimedCondition(getAbsTime(time), false);
115 }
116
117 /***
118 * Helper to return an absolute time in milliseconds, relative to now.
119 *
120 * @param time the relative time in milliseconds
121 * @return the absolute time
122 */
123 private static long getAbsTime(long time) {
124 return System.currentTimeMillis() + time;
125 }
126 }