1 /*
2 * Copyright 2000-2006 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26
27 package javax.print.attribute;
28
29 import java.io.Serializable;
30
31 import java.util.Date;
32
33 /**
34 * Class DateTimeSyntax is an abstract base class providing the common
35 * implementation of all attributes whose value is a date and time.
36 * <P>
37 * Under the hood, a date-time attribute is stored as a value of class <code>
38 * java.util.Date</code>. You can get a date-time attribute's Date value by
39 * calling {@link #getValue() <CODE>getValue()</CODE>}. A date-time attribute's
40 * Date value is established when it is constructed (see {@link
41 * #DateTimeSyntax(Date) <CODE>DateTimeSyntax(Date)</CODE>}). Once
42 * constructed, a date-time attribute's value is immutable.
43 * <P>
44 * To construct a date-time attribute from separate values of the year, month,
45 * day, hour, minute, and so on, use a <code>java.util.Calendar</code>
46 * object to construct a <code>java.util.Date</code> object, then use the
47 * <code>java.util.Date</code> object to construct the date-time attribute.
48 * To convert
49 * a date-time attribute to separate values of the year, month, day, hour,
50 * minute, and so on, create a <code>java.util.Calendar</code> object and
51 * set it to the <code>java.util.Date</code> from the date-time attribute. Class
52 * DateTimeSyntax stores its value in the form of a <code>java.util.Date
53 * </code>
54 * rather than a <code>java.util.Calendar</code> because it typically takes
55 * less memory to store and less time to compare a <code>java.util.Date</code>
56 * than a <code>java.util.Calendar</code>.
57 * <P>
58 *
59 * @author Alan Kaminsky
60 */
61 public abstract class DateTimeSyntax implements Serializable, Cloneable {
62
63 private static final long serialVersionUID = -1400819079791208582L;
64
65 // Hidden data members.
66
67 /**
68 * This date-time attribute's<code>java.util.Date</code> value.
69 * @serial
70 */
71 private Date value;
72
73 // Hidden constructors.
74
75 /**
76 * Construct a new date-time attribute with the given
77 * <code>java.util.Date </code> value.
78 *
79 * @param value <code>java.util.Date</code> value.
80 *
81 * @exception NullPointerException
82 * (unchecked exception) Thrown if <CODE>theValue</CODE> is null.
83 */
84 protected DateTimeSyntax(Date value) {
85 if (value == null) {
86 throw new NullPointerException("value is null");
87 }
88 this.value = value;
89 }
90
91 // Exported operations.
92
93 /**
94 * Returns this date-time attribute's <code>java.util.Date</code>
95 * value.
96 * @return the Date.
97 */
98 public Date getValue() {
99 return new Date (value.getTime());
100 }
101
102 // Exported operations inherited and overridden from class Object.
103
104 /**
105 * Returns whether this date-time attribute is equivalent to the passed in
106 * object. To be equivalent, all of the following conditions must be true:
107 * <OL TYPE=1>
108 * <LI>
109 * <CODE>object</CODE> is not null.
110 * <LI>
111 * <CODE>object</CODE> is an instance of class DateTimeSyntax.
112 * <LI>
113 * This date-time attribute's <code>java.util.Date</code> value and
114 * <CODE>object</CODE>'s <code>java.util.Date</code> value are
115 * equal. </OL>
116 *
117 * @param object Object to compare to.
118 *
119 * @return True if <CODE>object</CODE> is equivalent to this date-time
120 * attribute, false otherwise.
121 */
122 public boolean equals(Object object) {
123 return (object != null &&
124 object instanceof DateTimeSyntax &&
125 value.equals(((DateTimeSyntax) object).value));
126 }
127
128 /**
129 * Returns a hash code value for this date-time attribute. The hashcode is
130 * that of this attribute's <code>java.util.Date</code> value.
131 */
132 public int hashCode() {
133 return value.hashCode();
134 }
135
136 /**
137 * Returns a string value corresponding to this date-time attribute.
138 * The string value is just this attribute's
139 * <code>java.util.Date</code> value
140 * converted to a string.
141 */
142 public String toString() {
143 return "" + value;
144 }
145
146 }
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