100 * This class does not store or represent a year, time or time-zone.
101 * For example, the value "December 3rd" can be stored in a {@code MonthDay}.
102 * <p>
103 * Since a {@code MonthDay} does not possess a year, the leap day of
104 * February 29th is considered valid.
105 * <p>
106 * This class implements {@link TemporalAccessor} rather than {@link Temporal}.
107 * This is because it is not possible to define whether February 29th is valid or not
108 * without external information, preventing the implementation of plus/minus.
109 * Related to this, {@code MonthDay} only provides access to query and set the fields
110 * {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH}.
111 * <p>
112 * The ISO-8601 calendar system is the modern civil calendar system used today
113 * in most of the world. It is equivalent to the proleptic Gregorian calendar
114 * system, in which today's rules for leap years are applied for all time.
115 * For most applications written today, the ISO-8601 rules are entirely suitable.
116 * However, any application that makes use of historical dates, and requires them
117 * to be accurate will find the ISO-8601 approach unsuitable.
118 * <p>
119 * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
120 * class; programmers should treat instances that are
121 * {@linkplain #equals(Object) equal} as interchangeable and should not
122 * use instances for synchronization, or unpredictable behavior may
123 * occur. For example, in a future release, synchronization may fail.
124 * The {@code equals} method should be used for comparisons.
125 *
126 * @implSpec
127 * This class is immutable and thread-safe.
128 *
129 * @since 1.8
130 */
131 @jdk.internal.ValueBased
132 public final class MonthDay
133 implements TemporalAccessor, TemporalAdjuster, Comparable<MonthDay>, Serializable {
134
135 /**
136 * Serialization version.
137 */
138 @java.io.Serial
139 private static final long serialVersionUID = -939150713474957432L;
140
141 /**
142 * For backward compatibility of the serialized {@code MonthDay.class} object,
143 * explicitly declare the types of the serialized fields as defined in Java SE 8.
144 * Instances of {@code MonthDay} are serialized using the dedicated
145 * serialized form by {@code writeReplace}.
146 * @serialField month int The month-of-year.
147 * @serialField day int The day-of-month.
148 */
149 @Serial
150 private static final ObjectStreamField[] serialPersistentFields = {
151 new ObjectStreamField("month", int.class),
|
100 * This class does not store or represent a year, time or time-zone.
101 * For example, the value "December 3rd" can be stored in a {@code MonthDay}.
102 * <p>
103 * Since a {@code MonthDay} does not possess a year, the leap day of
104 * February 29th is considered valid.
105 * <p>
106 * This class implements {@link TemporalAccessor} rather than {@link Temporal}.
107 * This is because it is not possible to define whether February 29th is valid or not
108 * without external information, preventing the implementation of plus/minus.
109 * Related to this, {@code MonthDay} only provides access to query and set the fields
110 * {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH}.
111 * <p>
112 * The ISO-8601 calendar system is the modern civil calendar system used today
113 * in most of the world. It is equivalent to the proleptic Gregorian calendar
114 * system, in which today's rules for leap years are applied for all time.
115 * For most applications written today, the ISO-8601 rules are entirely suitable.
116 * However, any application that makes use of historical dates, and requires them
117 * to be accurate will find the ISO-8601 approach unsuitable.
118 * <p>
119 * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
120 * class; programmers should treat instances that are {@linkplain #equals(Object) equal}
121 * as interchangeable and should not use instances for synchronization, mutexes, or
122 * with {@linkplain java.lang.ref.Reference object references}.
123 *
124 * <div class="preview-block">
125 * <div class="preview-comment">
126 * When preview features are enabled, {@code MonthDay} is a {@linkplain Class#isValue value class}.
127 * Use of value class instances for synchronization, mutexes, or with
128 * {@linkplain java.lang.ref.Reference object references} result in
129 * {@link IdentityException}.
130 * </div>
131 * </div>
132 *
133 * @implSpec
134 * This class is immutable and thread-safe.
135 *
136 * @since 1.8
137 */
138 @jdk.internal.ValueBased
139 @jdk.internal.MigratedValueClass
140 public final class MonthDay
141 implements TemporalAccessor, TemporalAdjuster, Comparable<MonthDay>, Serializable {
142
143 /**
144 * Serialization version.
145 */
146 @java.io.Serial
147 private static final long serialVersionUID = -939150713474957432L;
148
149 /**
150 * For backward compatibility of the serialized {@code MonthDay.class} object,
151 * explicitly declare the types of the serialized fields as defined in Java SE 8.
152 * Instances of {@code MonthDay} are serialized using the dedicated
153 * serialized form by {@code writeReplace}.
154 * @serialField month int The month-of-year.
155 * @serialField day int The day-of-month.
156 */
157 @Serial
158 private static final ObjectStreamField[] serialPersistentFields = {
159 new ObjectStreamField("month", int.class),
|