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      1 /*
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      3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
      4  *
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      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.
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     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).
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     17  * You should have received a copy of the GNU General Public License version
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     19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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     25 
     26 /*
     27  * This file is available under and governed by the GNU General Public
     28  * License version 2 only, as published by the Free Software Foundation.
     29  * However, the following notice accompanied the original version of this
     30  * file:
     31  *
     32  * Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
     33  *
     34  * All rights reserved.
     35  *
     36  * Redistribution and use in source and binary forms, with or without
     37  * modification, are permitted provided that the following conditions are met:
     38  *
     39  *  * Redistributions of source code must retain the above copyright notice,
     40  *    this list of conditions and the following disclaimer.
     41  *
     42  *  * Redistributions in binary form must reproduce the above copyright notice,
     43  *    this list of conditions and the following disclaimer in the documentation
     44  *    and/or other materials provided with the distribution.
     45  *
     46  *  * Neither the name of JSR-310 nor the names of its contributors
     47  *    may be used to endorse or promote products derived from this software
     48  *    without specific prior written permission.
     49  *
     50  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     51  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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     60  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     61  */
     62 package java.time.chrono;
     63 
     64 import static java.time.temporal.ChronoField.ERA;
     65 
     66 import java.time.DateTimeException;
     67 import java.time.temporal.ChronoField;
     68 import java.time.temporal.TemporalField;
     69 import java.time.temporal.UnsupportedTemporalTypeException;
     70 import java.time.temporal.ValueRange;
     71 
     72 /**
     73  * An era in the Hijrah calendar system.
     74  * <p>
     75  * The Hijrah calendar system has only one era covering the
     76  * proleptic years greater than zero.
     77  * <p>
     78  * <b>Do not use {@code ordinal()} to obtain the numeric representation of {@code HijrahEra}.
     79  * Use {@code getValue()} instead.</b>
     80  *
     81  * @implSpec
     82  * This is an immutable and thread-safe enum.
     83  *
     84  * @since 1.8
     85  */
     86 public enum HijrahEra implements Era {
     87 
     88     /**
     89      * The singleton instance for the current era, 'Anno Hegirae',
     90      * which has the numeric value 1.
     91      */
     92     AH;
     93 
     94     //-----------------------------------------------------------------------
     95     /**
     96      * Obtains an instance of {@code HijrahEra} from an {@code int} value.
     97      * <p>
     98      * The current era, which is the only accepted value, has the value 1
     99      *
    100      * @param hijrahEra  the era to represent, only 1 supported
    101      * @return the HijrahEra.AH singleton, not null
    102      * @throws DateTimeException if the value is invalid
    103      */
    104     public static HijrahEra of(int hijrahEra) {
    105         if (hijrahEra == 1 ) {
    106             return AH;
    107         } else {
    108             throw new DateTimeException("Invalid era: " + hijrahEra);
    109         }
    110     }
    111 
    112     //-----------------------------------------------------------------------
    113     /**
    114      * Gets the numeric era {@code int} value.
    115      * <p>
    116      * The era AH has the value 1.
    117      *
    118      * @return the era value, 1 (AH)
    119      */
    120     @Override
    121     public int getValue() {
    122         return 1;
    123     }
    124 
    125     //-----------------------------------------------------------------------
    126     /**
    127      * Gets the range of valid values for the specified field.
    128      * <p>
    129      * The range object expresses the minimum and maximum valid values for a field.
    130      * This era is used to enhance the accuracy of the returned range.
    131      * If it is not possible to return the range, because the field is not supported
    132      * or for some other reason, an exception is thrown.
    133      * <p>
    134      * If the field is a {@link ChronoField} then the query is implemented here.
    135      * The {@code ERA} field returns the range.
    136      * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
    137      * <p>
    138      * If the field is not a {@code ChronoField}, then the result of this method
    139      * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
    140      * passing {@code this} as the argument.
    141      * Whether the range can be obtained is determined by the field.
    142      * <p>
    143      * The {@code ERA} field returns a range for the one valid Hijrah era.
    144      *
    145      * @param field  the field to query the range for, not null
    146      * @return the range of valid values for the field, not null
    147      * @throws DateTimeException if the range for the field cannot be obtained
    148      * @throws UnsupportedTemporalTypeException if the unit is not supported
    149      */
    150     @Override  // override as super would return range from 0 to 1
    151     public ValueRange range(TemporalField field) {
    152         if (field == ERA) {
    153             return ValueRange.of(1, 1);
    154         }
    155         return Era.super.range(field);
    156     }
    157 
    158 }
    159