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src/java.base/share/classes/java/time/Year.java

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 104  * <p>
 105  * <b>Note that years in the ISO chronology only align with years in the
 106  * Gregorian-Julian system for modern years. Parts of Russia did not switch to the
 107  * modern Gregorian/ISO rules until 1920.
 108  * As such, historical years must be treated with caution.</b>
 109  * <p>
 110  * This class does not store or represent a month, day, time or time-zone.
 111  * For example, the value "2007" can be stored in a {@code Year}.
 112  * <p>
 113  * Years represented by this class follow the ISO-8601 standard and use
 114  * the proleptic numbering system. Year 1 is preceded by year 0, then by year -1.
 115  * <p>
 116  * The ISO-8601 calendar system is the modern civil calendar system used today
 117  * in most of the world. It is equivalent to the proleptic Gregorian calendar
 118  * system, in which today's rules for leap years are applied for all time.
 119  * For most applications written today, the ISO-8601 rules are entirely suitable.
 120  * However, any application that makes use of historical dates, and requires them
 121  * to be accurate will find the ISO-8601 approach unsuitable.
 122  * <p>
 123  * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
 124  * class; programmers should treat instances that are
 125  * {@linkplain #equals(Object) equal} as interchangeable and should not
 126  * use instances for synchronization, or unpredictable behavior may
 127  * occur. For example, in a future release, synchronization may fail.
 128  * The {@code equals} method should be used for comparisons.







 129  *
 130  * @implSpec
 131  * This class is immutable and thread-safe.
 132  *
 133  * @since 1.8
 134  */
 135 @jdk.internal.ValueBased

 136 public final class Year
 137         implements Temporal, TemporalAdjuster, Comparable<Year>, Serializable {
 138 
 139     /**
 140      * The minimum supported year, '-999,999,999'.
 141      */
 142     public static final int MIN_VALUE = -999_999_999;
 143     /**
 144      * The maximum supported year, '+999,999,999'.
 145      */
 146     public static final int MAX_VALUE = 999_999_999;
 147 
 148     /**
 149      * Serialization version.
 150      */
 151     @java.io.Serial
 152     private static final long serialVersionUID = -23038383694477807L;
 153     /**
 154      * Parser.
 155      */

1099      * @serialData
1100      * <pre>
1101      *  out.writeByte(11);  // identifies a Year
1102      *  out.writeInt(year);
1103      * </pre>
1104      *
1105      * @return the instance of {@code Ser}, not null
1106      */
1107     @java.io.Serial
1108     private Object writeReplace() {
1109         return new Ser(Ser.YEAR_TYPE, this);
1110     }
1111 
1112     /**
1113      * Defend against malicious streams.
1114      *
1115      * @param s the stream to read
1116      * @throws InvalidObjectException always
1117      */
1118     @java.io.Serial

1119     private void readObject(ObjectInputStream s) throws InvalidObjectException {
1120         throw new InvalidObjectException("Deserialization via serialization delegate");
1121     }
1122 
1123     void writeExternal(DataOutput out) throws IOException {
1124         out.writeInt(year);
1125     }
1126 
1127     static Year readExternal(DataInput in) throws IOException {
1128         return Year.of(in.readInt());
1129     }
1130 
1131 }

 104  * <p>
 105  * <b>Note that years in the ISO chronology only align with years in the
 106  * Gregorian-Julian system for modern years. Parts of Russia did not switch to the
 107  * modern Gregorian/ISO rules until 1920.
 108  * As such, historical years must be treated with caution.</b>
 109  * <p>
 110  * This class does not store or represent a month, day, time or time-zone.
 111  * For example, the value "2007" can be stored in a {@code Year}.
 112  * <p>
 113  * Years represented by this class follow the ISO-8601 standard and use
 114  * the proleptic numbering system. Year 1 is preceded by year 0, then by year -1.
 115  * <p>
 116  * The ISO-8601 calendar system is the modern civil calendar system used today
 117  * in most of the world. It is equivalent to the proleptic Gregorian calendar
 118  * system, in which today's rules for leap years are applied for all time.
 119  * For most applications written today, the ISO-8601 rules are entirely suitable.
 120  * However, any application that makes use of historical dates, and requires them
 121  * to be accurate will find the ISO-8601 approach unsuitable.
 122  * <p>
 123  * This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>
 124  * class; programmers should treat instances that are {@linkplain #equals(Object) equal}
 125  * as interchangeable and should not use instances for synchronization, mutexes, or
 126  * with {@linkplain java.lang.ref.Reference object references}.
 127  *
 128  * <div class="preview-block">
 129  *      <div class="preview-comment">
 130  *          When preview features are enabled, {@code Year} is a {@linkplain Class#isValue value class}.
 131  *          Use of value class instances for synchronization, mutexes, or with
 132  *          {@linkplain java.lang.ref.Reference object references} result in
 133  *          {@link IdentityException}.
 134  *      </div>
 135  * </div>
 136  *
 137  * @implSpec
 138  * This class is immutable and thread-safe.
 139  *
 140  * @since 1.8
 141  */
 142 @jdk.internal.ValueBased
 143 @jdk.internal.MigratedValueClass
 144 public final class Year
 145         implements Temporal, TemporalAdjuster, Comparable<Year>, Serializable {
 146 
 147     /**
 148      * The minimum supported year, '-999,999,999'.
 149      */
 150     public static final int MIN_VALUE = -999_999_999;
 151     /**
 152      * The maximum supported year, '+999,999,999'.
 153      */
 154     public static final int MAX_VALUE = 999_999_999;
 155 
 156     /**
 157      * Serialization version.
 158      */
 159     @java.io.Serial
 160     private static final long serialVersionUID = -23038383694477807L;
 161     /**
 162      * Parser.
 163      */

1107      * @serialData
1108      * <pre>
1109      *  out.writeByte(11);  // identifies a Year
1110      *  out.writeInt(year);
1111      * </pre>
1112      *
1113      * @return the instance of {@code Ser}, not null
1114      */
1115     @java.io.Serial
1116     private Object writeReplace() {
1117         return new Ser(Ser.YEAR_TYPE, this);
1118     }
1119 
1120     /**
1121      * Defend against malicious streams.
1122      *
1123      * @param s the stream to read
1124      * @throws InvalidObjectException always
1125      */
1126     @java.io.Serial
1127     @SuppressWarnings("serial") // this method is not invoked for value classes
1128     private void readObject(ObjectInputStream s) throws InvalidObjectException {
1129         throw new InvalidObjectException("Deserialization via serialization delegate");
1130     }
1131 
1132     void writeExternal(DataOutput out) throws IOException {
1133         out.writeInt(year);
1134     }
1135 
1136     static Year readExternal(DataInput in) throws IOException {
1137         return Year.of(in.readInt());
1138     }
1139 
1140 }
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