1 /*
2 * Copyright (c) 2000, 2014, Oracle and/or its affiliates. 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * 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() getValue()}. A date-time attribute's
40 * Date value is established when it is constructed (see {@link
41 * #DateTimeSyntax(Date) DateTimeSyntax(Date)}). 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 *
58 * @author Alan Kaminsky
59 */
60 public abstract class DateTimeSyntax implements Serializable, Cloneable {
61
62 private static final long serialVersionUID = -1400819079791208582L;
63
64 // Hidden data members.
65
66 /**
67 * This date-time attribute's<code>java.util.Date</code> value.
68 * @serial
69 */
70 private Date value;
71
72 // Hidden constructors.
73
74 /**
75 * Construct a new date-time attribute with the given
76 * <code>java.util.Date </code> value.
77 *
78 * @param value <code>java.util.Date</code> value.
79 *
80 * @exception NullPointerException
81 * (unchecked exception) Thrown if <CODE>theValue</CODE> is null.
82 */
83 protected DateTimeSyntax(Date value) {
84 if (value == null) {
85 throw new NullPointerException("value is null");
86 }
87 this.value = value;
88 }
89
90 // Exported operations.
91
92 /**
93 * Returns this date-time attribute's <code>java.util.Date</code>
94 * value.
95 * @return the Date.
96 */
97 public Date getValue() {
98 return new Date (value.getTime());
99 }
100
101 // Exported operations inherited and overridden from class Object.
102
103 /**
104 * Returns whether this date-time attribute is equivalent to the passed in
105 * object. To be equivalent, all of the following conditions must be true:
106 * <OL TYPE=1>
107 * <LI>
108 * <CODE>object</CODE> is not null.
109 * <LI>
110 * <CODE>object</CODE> is an instance of class DateTimeSyntax.
111 * <LI>
112 * This date-time attribute's <code>java.util.Date</code> value and
113 * <CODE>object</CODE>'s <code>java.util.Date</code> value are
114 * equal. </OL>
115 *
116 * @param object Object to compare to.
117 *
118 * @return True if <CODE>object</CODE> is equivalent to this date-time
119 * attribute, false otherwise.
120 */
121 public boolean equals(Object object) {
122 return (object != null &&
123 object instanceof DateTimeSyntax &&
124 value.equals(((DateTimeSyntax) object).value));
125 }
126
127 /**
128 * Returns a hash code value for this date-time attribute. The hashcode is
129 * that of this attribute's <code>java.util.Date</code> value.
130 */
131 public int hashCode() {
132 return value.hashCode();
133 }
134
135 /**
136 * Returns a string value corresponding to this date-time attribute.
137 * The string value is just this attribute's
138 * <code>java.util.Date</code> value
139 * converted to a string.
140 */
141 public String toString() {
142 return "" + value;
143 }
144
145 }