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Java > Open Source Codes > org > exolab > jms > selector > SBool


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
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34  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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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 2000-2001,2003 (C) Exoffice Technologies Inc. All Rights Reserved.
42  */
43
44 package org.exolab.jms.selector;
45
46
47 /**
48  * This class is an adapter for the Boolean type.
49  *
50  * @version $Revision: 1.1 $ $Date: 2004/11/26 01:50:44 $
51  * @author <a HREF="mailto:tma@netspace.net.au">Tim Anderson</a>
52  * @see SObject
53  */
54 class SBool extends SObject {
55
56     /**
57      * Boolean true
58      */
59     public static final SBool TRUE = new SBool(Boolean.TRUE);
60
61     /**
62      * Boolean false
63      */
64     public static final SBool FALSE = new SBool(Boolean.FALSE);
65
66     /**
67      * The wrapped value
68      */
69     private Boolean JavaDoc _value;
70
71
72     /**
73      * Construct a new <code>SBool</code>
74      *
75      * @param value the boolean value
76      */
77     public SBool(final Boolean JavaDoc value) {
78         _value = value;
79     }
80
81     /**
82      * Returns the value of this, wrapped in a <code>Boolean</code>
83      *
84      * @return the value of this, wrapped in a <code>Boolean</code>
85      */
86     public final Object JavaDoc getObject() {
87         return _value;
88     }
89
90     /**
91      * Returns the value of this
92      *
93      * @return the value of this
94      */
95     public final boolean value() {
96         return _value.booleanValue();
97     }
98
99     /**
100      * Evaluates <code>this AND rhs</code>
101      *
102      * @param rhs the right hand side of the expression. May be null
103      * @return <code>SBool.TRUE</code> if <code>this</code> and
104      * <code>rhs</code> are <code>true</code>, <code>SBool.FALSE</code>
105      * if one is <code>false</code>, or <code>null</code> if <code>rhs</code>
106      * is <code>null</code>
107      */
108     public final SBool and(final SBool rhs) {
109         SBool result = null;
110         if (rhs != null) {
111             if (value() && rhs.value()) {
112                 result = SBool.TRUE;
113             } else {
114                 result = SBool.FALSE;
115             }
116         } else if (!value()) {
117             result = SBool.FALSE;
118         }
119
120         return result;
121     }
122
123     /**
124      * Evaluates <code>this OR rhs</code>
125      *
126      * @param rhs the right hand side of the expression. May be null
127      * @return <code>SBool.TRUE</code> if <code>this</code> is
128      * <code>true</code>, otherwise <code>rhs</code>
129      */
130     public final SBool or(final SBool rhs) {
131         SBool result = null;
132         if (value()) {
133             result = SBool.TRUE;
134         } else {
135             result = rhs;
136         }
137         return result;
138     }
139
140     /**
141      * Evaluates <code>NOT this</code>
142      *
143      * @return <code>SBool.TRUE</code> if <code>this</code> is
144      * <code>false</code>, otherwise <code>SBool.FALSE</code>
145      */
146     public final SBool not() {
147         SBool result = SBool.TRUE;
148         if (value()) {
149             result = SBool.FALSE;
150         }
151         return result;
152     }
153
154     /**
155      * Returns the type of this
156      *
157      * @return {@link Type#BOOLEAN}
158      */
159     public final Type type() {
160         return Type.BOOLEAN;
161     }
162
163 } //-- SBool
164
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