001 /*
002 * Copyright 2000-2006 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package javax.print.attribute;
027
028 import java.io.Serializable;
029
030 import java.util.Date;
031
032 /**
033 * Class DateTimeSyntax is an abstract base class providing the common
034 * implementation of all attributes whose value is a date and time.
035 * <P>
036 * Under the hood, a date-time attribute is stored as a value of class <code>
037 * java.util.Date</code>. You can get a date-time attribute's Date value by
038 * calling {@link #getValue() <CODE>getValue()</CODE>}. A date-time attribute's
039 * Date value is established when it is constructed (see {@link
040 * #DateTimeSyntax(Date) <CODE>DateTimeSyntax(Date)</CODE>}). Once
041 * constructed, a date-time attribute's value is immutable.
042 * <P>
043 * To construct a date-time attribute from separate values of the year, month,
044 * day, hour, minute, and so on, use a <code>java.util.Calendar</code>
045 * object to construct a <code>java.util.Date</code> object, then use the
046 * <code>java.util.Date</code> object to construct the date-time attribute.
047 * To convert
048 * a date-time attribute to separate values of the year, month, day, hour,
049 * minute, and so on, create a <code>java.util.Calendar</code> object and
050 * set it to the <code>java.util.Date</code> from the date-time attribute. Class
051 * DateTimeSyntax stores its value in the form of a <code>java.util.Date
052 * </code>
053 * rather than a <code>java.util.Calendar</code> because it typically takes
054 * less memory to store and less time to compare a <code>java.util.Date</code>
055 * than a <code>java.util.Calendar</code>.
056 * <P>
057 *
058 * @author Alan Kaminsky
059 */
060 public abstract class DateTimeSyntax implements Serializable, Cloneable {
061
062 private static final long serialVersionUID = -1400819079791208582L;
063
064 // Hidden data members.
065
066 /**
067 * This date-time attribute's<code>java.util.Date</code> value.
068 * @serial
069 */
070 private Date value;
071
072 // Hidden constructors.
073
074 /**
075 * Construct a new date-time attribute with the given
076 * <code>java.util.Date </code> value.
077 *
078 * @param value <code>java.util.Date</code> value.
079 *
080 * @exception NullPointerException
081 * (unchecked exception) Thrown if <CODE>theValue</CODE> is null.
082 */
083 protected DateTimeSyntax(Date value) {
084 if (value == null) {
085 throw new NullPointerException("value is null");
086 }
087 this .value = value;
088 }
089
090 // Exported operations.
091
092 /**
093 * Returns this date-time attribute's <code>java.util.Date</code>
094 * value.
095 * @return the Date.
096 */
097 public Date getValue() {
098 return new Date(value.getTime());
099 }
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 && object instanceof DateTimeSyntax && value
123 .equals(((DateTimeSyntax) object).value));
124 }
125
126 /**
127 * Returns a hash code value for this date-time attribute. The hashcode is
128 * that of this attribute's <code>java.util.Date</code> value.
129 */
130 public int hashCode() {
131 return value.hashCode();
132 }
133
134 /**
135 * Returns a string value corresponding to this date-time attribute.
136 * The string value is just this attribute's
137 * <code>java.util.Date</code> value
138 * converted to a string.
139 */
140 public String toString() {
141 return "" + value;
142 }
143
144 }
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