1/*
2 * Copyright (c) 2012, 2013, 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
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24 */
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
52 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
53 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
54 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
55 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
56 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
57 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
58 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
59 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
60 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
61 */
62package java.time.chrono;
63
64import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_MONTH;
65import static java.time.temporal.ChronoField.ALIGNED_DAY_OF_WEEK_IN_YEAR;
66import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_MONTH;
67import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_YEAR;
68import static java.time.temporal.ChronoField.DAY_OF_MONTH;
69import static java.time.temporal.ChronoField.DAY_OF_WEEK;
70import static java.time.temporal.ChronoField.DAY_OF_YEAR;
71import static java.time.temporal.ChronoField.EPOCH_DAY;
72import static java.time.temporal.ChronoField.ERA;
73import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
74import static java.time.temporal.ChronoField.PROLEPTIC_MONTH;
75import static java.time.temporal.ChronoField.YEAR;
76import static java.time.temporal.ChronoField.YEAR_OF_ERA;
77import static java.time.temporal.ChronoUnit.DAYS;
78import static java.time.temporal.ChronoUnit.MONTHS;
79import static java.time.temporal.ChronoUnit.WEEKS;
80import static java.time.temporal.TemporalAdjusters.nextOrSame;
81
82import java.io.DataInput;
83import java.io.DataOutput;
84import java.io.IOException;
85import java.io.InvalidObjectException;
86import java.io.ObjectInputStream;
87import java.io.ObjectStreamException;
88import java.io.Serializable;
89import java.time.DateTimeException;
90import java.time.DayOfWeek;
91import java.time.format.ResolverStyle;
92import java.time.temporal.ChronoField;
93import java.time.temporal.TemporalAdjusters;
94import java.time.temporal.TemporalField;
95import java.time.temporal.ValueRange;
96import java.util.Comparator;
97import java.util.HashSet;
98import java.util.List;
99import java.util.Locale;
100import java.util.Map;
101import java.util.Objects;
102import java.util.ServiceLoader;
103import java.util.Set;
104import java.util.concurrent.ConcurrentHashMap;
105
106import sun.util.logging.PlatformLogger;
107
108/**
109 * An abstract implementation of a calendar system, used to organize and identify dates.
110 * <p>
111 * The main date and time API is built on the ISO calendar system.
112 * The chronology operates behind the scenes to represent the general concept of a calendar system.
113 * <p>
114 * See {@link Chronology} for more details.
115 *
116 * @implSpec
117 * This class is separated from the {@code Chronology} interface so that the static methods
118 * are not inherited. While {@code Chronology} can be implemented directly, it is strongly
119 * recommended to extend this abstract class instead.
120 * <p>
121 * This class must be implemented with care to ensure other classes operate correctly.
122 * All implementations that can be instantiated must be final, immutable and thread-safe.
123 * Subclasses should be Serializable wherever possible.
124 *
125 * @since 1.8
126 */
127public abstract class AbstractChronology implements Chronology {
128
129    /**
130     * ChronoLocalDate order constant.
131     */
132    static final Comparator<ChronoLocalDate> DATE_ORDER =
133        (Comparator<ChronoLocalDate> & Serializable) (date1, date2) -> {
134            return Long.compare(date1.toEpochDay(), date2.toEpochDay());
135        };
136    /**
137     * ChronoLocalDateTime order constant.
138     */
139    static final Comparator<ChronoLocalDateTime<? extends ChronoLocalDate>> DATE_TIME_ORDER =
140        (Comparator<ChronoLocalDateTime<? extends ChronoLocalDate>> & Serializable) (dateTime1, dateTime2) -> {
141            int cmp = Long.compare(dateTime1.toLocalDate().toEpochDay(), dateTime2.toLocalDate().toEpochDay());
142            if (cmp == 0) {
143                cmp = Long.compare(dateTime1.toLocalTime().toNanoOfDay(), dateTime2.toLocalTime().toNanoOfDay());
144            }
145            return cmp;
146        };
147    /**
148     * ChronoZonedDateTime order constant.
149     */
150    static final Comparator<ChronoZonedDateTime<?>> INSTANT_ORDER =
151            (Comparator<ChronoZonedDateTime<?>> & Serializable) (dateTime1, dateTime2) -> {
152                int cmp = Long.compare(dateTime1.toEpochSecond(), dateTime2.toEpochSecond());
153                if (cmp == 0) {
154                    cmp = Long.compare(dateTime1.toLocalTime().getNano(), dateTime2.toLocalTime().getNano());
155                }
156                return cmp;
157            };
158
159    /**
160     * Map of available calendars by ID.
161     */
162    private static final ConcurrentHashMap<String, Chronology> CHRONOS_BY_ID = new ConcurrentHashMap<>();
163    /**
164     * Map of available calendars by calendar type.
165     */
166    private static final ConcurrentHashMap<String, Chronology> CHRONOS_BY_TYPE = new ConcurrentHashMap<>();
167
168    /**
169     * Register a Chronology by its ID and type for lookup by {@link #of(String)}.
170     * Chronologies must not be registered until they are completely constructed.
171     * Specifically, not in the constructor of Chronology.
172     *
173     * @param chrono the chronology to register; not null
174     * @return the already registered Chronology if any, may be null
175     */
176    static Chronology registerChrono(Chronology chrono) {
177        return registerChrono(chrono, chrono.getId());
178    }
179
180    /**
181     * Register a Chronology by ID and type for lookup by {@link #of(String)}.
182     * Chronos must not be registered until they are completely constructed.
183     * Specifically, not in the constructor of Chronology.
184     *
185     * @param chrono the chronology to register; not null
186     * @param id the ID to register the chronology; not null
187     * @return the already registered Chronology if any, may be null
188     */
189    static Chronology registerChrono(Chronology chrono, String id) {
190        Chronology prev = CHRONOS_BY_ID.putIfAbsent(id, chrono);
191        if (prev == null) {
192            String type = chrono.getCalendarType();
193            if (type != null) {
194                CHRONOS_BY_TYPE.putIfAbsent(type, chrono);
195            }
196        }
197        return prev;
198    }
199
200    /**
201     * Initialization of the maps from id and type to Chronology.
202     * The ServiceLoader is used to find and register any implementations
203     * of {@link java.time.chrono.AbstractChronology} found in the bootclass loader.
204     * The built-in chronologies are registered explicitly.
205     * Calendars configured via the Thread's context classloader are local
206     * to that thread and are ignored.
207     * <p>
208     * The initialization is done only once using the registration
209     * of the IsoChronology as the test and the final step.
210     * Multiple threads may perform the initialization concurrently.
211     * Only the first registration of each Chronology is retained by the
212     * ConcurrentHashMap.
213     * @return true if the cache was initialized
214     */
215    private static boolean initCache() {
216        if (CHRONOS_BY_ID.get("ISO") == null) {
217            // Initialization is incomplete
218
219            // Register built-in Chronologies
220            registerChrono(HijrahChronology.INSTANCE);
221            registerChrono(JapaneseChronology.INSTANCE);
222            registerChrono(MinguoChronology.INSTANCE);
223            registerChrono(ThaiBuddhistChronology.INSTANCE);
224
225            // Register Chronologies from the ServiceLoader
226            @SuppressWarnings("rawtypes")
227            ServiceLoader<AbstractChronology> loader =  ServiceLoader.load(AbstractChronology.class, null);
228            for (AbstractChronology chrono : loader) {
229                String id = chrono.getId();
230                if (id.equals("ISO") || registerChrono(chrono) != null) {
231                    // Log the attempt to replace an existing Chronology
232                    PlatformLogger logger = PlatformLogger.getLogger("java.time.chrono");
233                    logger.warning("Ignoring duplicate Chronology, from ServiceLoader configuration "  + id);
234                }
235            }
236
237            // finally, register IsoChronology to mark initialization is complete
238            registerChrono(IsoChronology.INSTANCE);
239            return true;
240        }
241        return false;
242    }
243
244    //-----------------------------------------------------------------------
245    /**
246     * Obtains an instance of {@code Chronology} from a locale.
247     * <p>
248     * See {@link Chronology#ofLocale(Locale)}.
249     *
250     * @param locale  the locale to use to obtain the calendar system, not null
251     * @return the calendar system associated with the locale, not null
252     * @throws java.time.DateTimeException if the locale-specified calendar cannot be found
253     */
254    static Chronology ofLocale(Locale locale) {
255        Objects.requireNonNull(locale, "locale");
256        String type = locale.getUnicodeLocaleType("ca");
257        if (type == null || "iso".equals(type) || "iso8601".equals(type)) {
258            return IsoChronology.INSTANCE;
259        }
260        // Not pre-defined; lookup by the type
261        do {
262            Chronology chrono = CHRONOS_BY_TYPE.get(type);
263            if (chrono != null) {
264                return chrono;
265            }
266            // If not found, do the initialization (once) and repeat the lookup
267        } while (initCache());
268
269        // Look for a Chronology using ServiceLoader of the Thread's ContextClassLoader
270        // Application provided Chronologies must not be cached
271        @SuppressWarnings("rawtypes")
272        ServiceLoader<Chronology> loader = ServiceLoader.load(Chronology.class);
273        for (Chronology chrono : loader) {
274            if (type.equals(chrono.getCalendarType())) {
275                return chrono;
276            }
277        }
278        throw new DateTimeException("Unknown calendar system: " + type);
279    }
280
281    //-----------------------------------------------------------------------
282    /**
283     * Obtains an instance of {@code Chronology} from a chronology ID or
284     * calendar system type.
285     * <p>
286     * See {@link Chronology#of(String)}.
287     *
288     * @param id  the chronology ID or calendar system type, not null
289     * @return the chronology with the identifier requested, not null
290     * @throws java.time.DateTimeException if the chronology cannot be found
291     */
292    static Chronology of(String id) {
293        Objects.requireNonNull(id, "id");
294        do {
295            Chronology chrono = of0(id);
296            if (chrono != null) {
297                return chrono;
298            }
299            // If not found, do the initialization (once) and repeat the lookup
300        } while (initCache());
301
302        // Look for a Chronology using ServiceLoader of the Thread's ContextClassLoader
303        // Application provided Chronologies must not be cached
304        @SuppressWarnings("rawtypes")
305        ServiceLoader<Chronology> loader = ServiceLoader.load(Chronology.class);
306        for (Chronology chrono : loader) {
307            if (id.equals(chrono.getId()) || id.equals(chrono.getCalendarType())) {
308                return chrono;
309            }
310        }
311        throw new DateTimeException("Unknown chronology: " + id);
312    }
313
314    /**
315     * Obtains an instance of {@code Chronology} from a chronology ID or
316     * calendar system type.
317     *
318     * @param id  the chronology ID or calendar system type, not null
319     * @return the chronology with the identifier requested, or {@code null} if not found
320     */
321    private static Chronology of0(String id) {
322        Chronology chrono = CHRONOS_BY_ID.get(id);
323        if (chrono == null) {
324            chrono = CHRONOS_BY_TYPE.get(id);
325        }
326        return chrono;
327    }
328
329    /**
330     * Returns the available chronologies.
331     * <p>
332     * Each returned {@code Chronology} is available for use in the system.
333     * The set of chronologies includes the system chronologies and
334     * any chronologies provided by the application via ServiceLoader
335     * configuration.
336     *
337     * @return the independent, modifiable set of the available chronology IDs, not null
338     */
339    static Set<Chronology> getAvailableChronologies() {
340        initCache();       // force initialization
341        HashSet<Chronology> chronos = new HashSet<>(CHRONOS_BY_ID.values());
342
343        /// Add in Chronologies from the ServiceLoader configuration
344        @SuppressWarnings("rawtypes")
345        ServiceLoader<Chronology> loader = ServiceLoader.load(Chronology.class);
346        for (Chronology chrono : loader) {
347            chronos.add(chrono);
348        }
349        return chronos;
350    }
351
352    //-----------------------------------------------------------------------
353    /**
354     * Creates an instance.
355     */
356    protected AbstractChronology() {
357    }
358
359    //-----------------------------------------------------------------------
360    /**
361     * Resolves parsed {@code ChronoField} values into a date during parsing.
362     * <p>
363     * Most {@code TemporalField} implementations are resolved using the
364     * resolve method on the field. By contrast, the {@code ChronoField} class
365     * defines fields that only have meaning relative to the chronology.
366     * As such, {@code ChronoField} date fields are resolved here in the
367     * context of a specific chronology.
368     * <p>
369     * {@code ChronoField} instances are resolved by this method, which may
370     * be overridden in subclasses.
371     * <ul>
372     * <li>{@code EPOCH_DAY} - If present, this is converted to a date and
373     *  all other date fields are then cross-checked against the date.
374     * <li>{@code PROLEPTIC_MONTH} - If present, then it is split into the
375     *  {@code YEAR} and {@code MONTH_OF_YEAR}. If the mode is strict or smart
376     *  then the field is validated.
377     * <li>{@code YEAR_OF_ERA} and {@code ERA} - If both are present, then they
378     *  are combined to form a {@code YEAR}. In lenient mode, the {@code YEAR_OF_ERA}
379     *  range is not validated, in smart and strict mode it is. The {@code ERA} is
380     *  validated for range in all three modes. If only the {@code YEAR_OF_ERA} is
381     *  present, and the mode is smart or lenient, then the last available era
382     *  is assumed. In strict mode, no era is assumed and the {@code YEAR_OF_ERA} is
383     *  left untouched. If only the {@code ERA} is present, then it is left untouched.
384     * <li>{@code YEAR}, {@code MONTH_OF_YEAR} and {@code DAY_OF_MONTH} -
385     *  If all three are present, then they are combined to form a date.
386     *  In all three modes, the {@code YEAR} is validated.
387     *  If the mode is smart or strict, then the month and day are validated.
388     *  If the mode is lenient, then the date is combined in a manner equivalent to
389     *  creating a date on the first day of the first month in the requested year,
390     *  then adding the difference in months, then the difference in days.
391     *  If the mode is smart, and the day-of-month is greater than the maximum for
392     *  the year-month, then the day-of-month is adjusted to the last day-of-month.
393     *  If the mode is strict, then the three fields must form a valid date.
394     * <li>{@code YEAR} and {@code DAY_OF_YEAR} -
395     *  If both are present, then they are combined to form a date.
396     *  In all three modes, the {@code YEAR} is validated.
397     *  If the mode is lenient, then the date is combined in a manner equivalent to
398     *  creating a date on the first day of the requested year, then adding
399     *  the difference in days.
400     *  If the mode is smart or strict, then the two fields must form a valid date.
401     * <li>{@code YEAR}, {@code MONTH_OF_YEAR}, {@code ALIGNED_WEEK_OF_MONTH} and
402     *  {@code ALIGNED_DAY_OF_WEEK_IN_MONTH} -
403     *  If all four are present, then they are combined to form a date.
404     *  In all three modes, the {@code YEAR} is validated.
405     *  If the mode is lenient, then the date is combined in a manner equivalent to
406     *  creating a date on the first day of the first month in the requested year, then adding
407     *  the difference in months, then the difference in weeks, then in days.
408     *  If the mode is smart or strict, then the all four fields are validated to
409     *  their outer ranges. The date is then combined in a manner equivalent to
410     *  creating a date on the first day of the requested year and month, then adding
411     *  the amount in weeks and days to reach their values. If the mode is strict,
412     *  the date is additionally validated to check that the day and week adjustment
413     *  did not change the month.
414     * <li>{@code YEAR}, {@code MONTH_OF_YEAR}, {@code ALIGNED_WEEK_OF_MONTH} and
415     *  {@code DAY_OF_WEEK} - If all four are present, then they are combined to
416     *  form a date. The approach is the same as described above for
417     *  years, months and weeks in {@code ALIGNED_DAY_OF_WEEK_IN_MONTH}.
418     *  The day-of-week is adjusted as the next or same matching day-of-week once
419     *  the years, months and weeks have been handled.
420     * <li>{@code YEAR}, {@code ALIGNED_WEEK_OF_YEAR} and {@code ALIGNED_DAY_OF_WEEK_IN_YEAR} -
421     *  If all three are present, then they are combined to form a date.
422     *  In all three modes, the {@code YEAR} is validated.
423     *  If the mode is lenient, then the date is combined in a manner equivalent to
424     *  creating a date on the first day of the requested year, then adding
425     *  the difference in weeks, then in days.
426     *  If the mode is smart or strict, then the all three fields are validated to
427     *  their outer ranges. The date is then combined in a manner equivalent to
428     *  creating a date on the first day of the requested year, then adding
429     *  the amount in weeks and days to reach their values. If the mode is strict,
430     *  the date is additionally validated to check that the day and week adjustment
431     *  did not change the year.
432     * <li>{@code YEAR}, {@code ALIGNED_WEEK_OF_YEAR} and {@code DAY_OF_WEEK} -
433     *  If all three are present, then they are combined to form a date.
434     *  The approach is the same as described above for years and weeks in
435     *  {@code ALIGNED_DAY_OF_WEEK_IN_YEAR}. The day-of-week is adjusted as the
436     *  next or same matching day-of-week once the years and weeks have been handled.
437     * </ul>
438     * <p>
439     * The default implementation is suitable for most calendar systems.
440     * If {@link java.time.temporal.ChronoField#YEAR_OF_ERA} is found without an {@link java.time.temporal.ChronoField#ERA}
441     * then the last era in {@link #eras()} is used.
442     * The implementation assumes a 7 day week, that the first day-of-month
443     * has the value 1, that first day-of-year has the value 1, and that the
444     * first of the month and year always exists.
445     *
446     * @param fieldValues  the map of fields to values, which can be updated, not null
447     * @param resolverStyle  the requested type of resolve, not null
448     * @return the resolved date, null if insufficient information to create a date
449     * @throws java.time.DateTimeException if the date cannot be resolved, typically
450     *  because of a conflict in the input data
451     */
452    @Override
453    public ChronoLocalDate resolveDate(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
454        // check epoch-day before inventing era
455        if (fieldValues.containsKey(EPOCH_DAY)) {
456            return dateEpochDay(fieldValues.remove(EPOCH_DAY));
457        }
458
459        // fix proleptic month before inventing era
460        resolveProlepticMonth(fieldValues, resolverStyle);
461
462        // invent era if necessary to resolve year-of-era
463        ChronoLocalDate resolved = resolveYearOfEra(fieldValues, resolverStyle);
464        if (resolved != null) {
465            return resolved;
466        }
467
468        // build date
469        if (fieldValues.containsKey(YEAR)) {
470            if (fieldValues.containsKey(MONTH_OF_YEAR)) {
471                if (fieldValues.containsKey(DAY_OF_MONTH)) {
472                    return resolveYMD(fieldValues, resolverStyle);
473                }
474                if (fieldValues.containsKey(ALIGNED_WEEK_OF_MONTH)) {
475                    if (fieldValues.containsKey(ALIGNED_DAY_OF_WEEK_IN_MONTH)) {
476                        return resolveYMAA(fieldValues, resolverStyle);
477                    }
478                    if (fieldValues.containsKey(DAY_OF_WEEK)) {
479                        return resolveYMAD(fieldValues, resolverStyle);
480                    }
481                }
482            }
483            if (fieldValues.containsKey(DAY_OF_YEAR)) {
484                return resolveYD(fieldValues, resolverStyle);
485            }
486            if (fieldValues.containsKey(ALIGNED_WEEK_OF_YEAR)) {
487                if (fieldValues.containsKey(ALIGNED_DAY_OF_WEEK_IN_YEAR)) {
488                    return resolveYAA(fieldValues, resolverStyle);
489                }
490                if (fieldValues.containsKey(DAY_OF_WEEK)) {
491                    return resolveYAD(fieldValues, resolverStyle);
492                }
493            }
494        }
495        return null;
496    }
497
498    void resolveProlepticMonth(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
499        Long pMonth = fieldValues.remove(PROLEPTIC_MONTH);
500        if (pMonth != null) {
501            if (resolverStyle != ResolverStyle.LENIENT) {
502                PROLEPTIC_MONTH.checkValidValue(pMonth);
503            }
504            // first day-of-month is likely to be safest for setting proleptic-month
505            // cannot add to year zero, as not all chronologies have a year zero
506            ChronoLocalDate chronoDate = dateNow()
507                    .with(DAY_OF_MONTH, 1).with(PROLEPTIC_MONTH, pMonth);
508            addFieldValue(fieldValues, MONTH_OF_YEAR, chronoDate.get(MONTH_OF_YEAR));
509            addFieldValue(fieldValues, YEAR, chronoDate.get(YEAR));
510        }
511    }
512
513    ChronoLocalDate resolveYearOfEra(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
514        Long yoeLong = fieldValues.remove(YEAR_OF_ERA);
515        if (yoeLong != null) {
516            Long eraLong = fieldValues.remove(ERA);
517            int yoe;
518            if (resolverStyle != ResolverStyle.LENIENT) {
519                yoe = range(YEAR_OF_ERA).checkValidIntValue(yoeLong, YEAR_OF_ERA);
520            } else {
521                yoe = Math.toIntExact(yoeLong);
522            }
523            if (eraLong != null) {
524                Era eraObj = eraOf(range(ERA).checkValidIntValue(eraLong, ERA));
525                addFieldValue(fieldValues, YEAR, prolepticYear(eraObj, yoe));
526            } else {
527                if (fieldValues.containsKey(YEAR)) {
528                    int year = range(YEAR).checkValidIntValue(fieldValues.get(YEAR), YEAR);
529                    ChronoLocalDate chronoDate = dateYearDay(year, 1);
530                    addFieldValue(fieldValues, YEAR, prolepticYear(chronoDate.getEra(), yoe));
531                } else if (resolverStyle == ResolverStyle.STRICT) {
532                    // do not invent era if strict
533                    // reinstate the field removed earlier, no cross-check issues
534                    fieldValues.put(YEAR_OF_ERA, yoeLong);
535                } else {
536                    List<Era> eras = eras();
537                    if (eras.isEmpty()) {
538                        addFieldValue(fieldValues, YEAR, yoe);
539                    } else {
540                        Era eraObj = eras.get(eras.size() - 1);
541                        addFieldValue(fieldValues, YEAR, prolepticYear(eraObj, yoe));
542                    }
543                }
544            }
545        } else if (fieldValues.containsKey(ERA)) {
546            range(ERA).checkValidValue(fieldValues.get(ERA), ERA);  // always validated
547        }
548        return null;
549    }
550
551    ChronoLocalDate resolveYMD(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
552        int y = range(YEAR).checkValidIntValue(fieldValues.remove(YEAR), YEAR);
553        if (resolverStyle == ResolverStyle.LENIENT) {
554            long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
555            long days = Math.subtractExact(fieldValues.remove(DAY_OF_MONTH), 1);
556            return date(y, 1, 1).plus(months, MONTHS).plus(days, DAYS);
557        }
558        int moy = range(MONTH_OF_YEAR).checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR), MONTH_OF_YEAR);
559        ValueRange domRange = range(DAY_OF_MONTH);
560        int dom = domRange.checkValidIntValue(fieldValues.remove(DAY_OF_MONTH), DAY_OF_MONTH);
561        if (resolverStyle == ResolverStyle.SMART) {  // previous valid
562            try {
563                return date(y, moy, dom);
564            } catch (DateTimeException ex) {
565                return date(y, moy, 1).with(TemporalAdjusters.lastDayOfMonth());
566            }
567        }
568        return date(y, moy, dom);
569    }
570
571    ChronoLocalDate resolveYD(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
572        int y = range(YEAR).checkValidIntValue(fieldValues.remove(YEAR), YEAR);
573        if (resolverStyle == ResolverStyle.LENIENT) {
574            long days = Math.subtractExact(fieldValues.remove(DAY_OF_YEAR), 1);
575            return dateYearDay(y, 1).plus(days, DAYS);
576        }
577        int doy = range(DAY_OF_YEAR).checkValidIntValue(fieldValues.remove(DAY_OF_YEAR), DAY_OF_YEAR);
578        return dateYearDay(y, doy);  // smart is same as strict
579    }
580
581    ChronoLocalDate resolveYMAA(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
582        int y = range(YEAR).checkValidIntValue(fieldValues.remove(YEAR), YEAR);
583        if (resolverStyle == ResolverStyle.LENIENT) {
584            long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
585            long weeks = Math.subtractExact(fieldValues.remove(ALIGNED_WEEK_OF_MONTH), 1);
586            long days = Math.subtractExact(fieldValues.remove(ALIGNED_DAY_OF_WEEK_IN_MONTH), 1);
587            return date(y, 1, 1).plus(months, MONTHS).plus(weeks, WEEKS).plus(days, DAYS);
588        }
589        int moy = range(MONTH_OF_YEAR).checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR), MONTH_OF_YEAR);
590        int aw = range(ALIGNED_WEEK_OF_MONTH).checkValidIntValue(fieldValues.remove(ALIGNED_WEEK_OF_MONTH), ALIGNED_WEEK_OF_MONTH);
591        int ad = range(ALIGNED_DAY_OF_WEEK_IN_MONTH).checkValidIntValue(fieldValues.remove(ALIGNED_DAY_OF_WEEK_IN_MONTH), ALIGNED_DAY_OF_WEEK_IN_MONTH);
592        ChronoLocalDate date = date(y, moy, 1).plus((aw - 1) * 7 + (ad - 1), DAYS);
593        if (resolverStyle == ResolverStyle.STRICT && date.get(MONTH_OF_YEAR) != moy) {
594            throw new DateTimeException("Strict mode rejected resolved date as it is in a different month");
595        }
596        return date;
597    }
598
599    ChronoLocalDate resolveYMAD(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
600        int y = range(YEAR).checkValidIntValue(fieldValues.remove(YEAR), YEAR);
601        if (resolverStyle == ResolverStyle.LENIENT) {
602            long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
603            long weeks = Math.subtractExact(fieldValues.remove(ALIGNED_WEEK_OF_MONTH), 1);
604            long dow = Math.subtractExact(fieldValues.remove(DAY_OF_WEEK), 1);
605            return resolveAligned(date(y, 1, 1), months, weeks, dow);
606        }
607        int moy = range(MONTH_OF_YEAR).checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR), MONTH_OF_YEAR);
608        int aw = range(ALIGNED_WEEK_OF_MONTH).checkValidIntValue(fieldValues.remove(ALIGNED_WEEK_OF_MONTH), ALIGNED_WEEK_OF_MONTH);
609        int dow = range(DAY_OF_WEEK).checkValidIntValue(fieldValues.remove(DAY_OF_WEEK), DAY_OF_WEEK);
610        ChronoLocalDate date = date(y, moy, 1).plus((aw - 1) * 7, DAYS).with(nextOrSame(DayOfWeek.of(dow)));
611        if (resolverStyle == ResolverStyle.STRICT && date.get(MONTH_OF_YEAR) != moy) {
612            throw new DateTimeException("Strict mode rejected resolved date as it is in a different month");
613        }
614        return date;
615    }
616
617    ChronoLocalDate resolveYAA(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
618        int y = range(YEAR).checkValidIntValue(fieldValues.remove(YEAR), YEAR);
619        if (resolverStyle == ResolverStyle.LENIENT) {
620            long weeks = Math.subtractExact(fieldValues.remove(ALIGNED_WEEK_OF_YEAR), 1);
621            long days = Math.subtractExact(fieldValues.remove(ALIGNED_DAY_OF_WEEK_IN_YEAR), 1);
622            return dateYearDay(y, 1).plus(weeks, WEEKS).plus(days, DAYS);
623        }
624        int aw = range(ALIGNED_WEEK_OF_YEAR).checkValidIntValue(fieldValues.remove(ALIGNED_WEEK_OF_YEAR), ALIGNED_WEEK_OF_YEAR);
625        int ad = range(ALIGNED_DAY_OF_WEEK_IN_YEAR).checkValidIntValue(fieldValues.remove(ALIGNED_DAY_OF_WEEK_IN_YEAR), ALIGNED_DAY_OF_WEEK_IN_YEAR);
626        ChronoLocalDate date = dateYearDay(y, 1).plus((aw - 1) * 7 + (ad - 1), DAYS);
627        if (resolverStyle == ResolverStyle.STRICT && date.get(YEAR) != y) {
628            throw new DateTimeException("Strict mode rejected resolved date as it is in a different year");
629        }
630        return date;
631    }
632
633    ChronoLocalDate resolveYAD(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
634        int y = range(YEAR).checkValidIntValue(fieldValues.remove(YEAR), YEAR);
635        if (resolverStyle == ResolverStyle.LENIENT) {
636            long weeks = Math.subtractExact(fieldValues.remove(ALIGNED_WEEK_OF_YEAR), 1);
637            long dow = Math.subtractExact(fieldValues.remove(DAY_OF_WEEK), 1);
638            return resolveAligned(dateYearDay(y, 1), 0, weeks, dow);
639        }
640        int aw = range(ALIGNED_WEEK_OF_YEAR).checkValidIntValue(fieldValues.remove(ALIGNED_WEEK_OF_YEAR), ALIGNED_WEEK_OF_YEAR);
641        int dow = range(DAY_OF_WEEK).checkValidIntValue(fieldValues.remove(DAY_OF_WEEK), DAY_OF_WEEK);
642        ChronoLocalDate date = dateYearDay(y, 1).plus((aw - 1) * 7, DAYS).with(nextOrSame(DayOfWeek.of(dow)));
643        if (resolverStyle == ResolverStyle.STRICT && date.get(YEAR) != y) {
644            throw new DateTimeException("Strict mode rejected resolved date as it is in a different year");
645        }
646        return date;
647    }
648
649    ChronoLocalDate resolveAligned(ChronoLocalDate base, long months, long weeks, long dow) {
650        ChronoLocalDate date = base.plus(months, MONTHS).plus(weeks, WEEKS);
651        if (dow > 7) {
652            date = date.plus((dow - 1) / 7, WEEKS);
653            dow = ((dow - 1) % 7) + 1;
654        } else if (dow < 1) {
655            date = date.plus(Math.subtractExact(dow,  7) / 7, WEEKS);
656            dow = ((dow + 6) % 7) + 1;
657        }
658        return date.with(nextOrSame(DayOfWeek.of((int) dow)));
659    }
660
661    /**
662     * Adds a field-value pair to the map, checking for conflicts.
663     * <p>
664     * If the field is not already present, then the field-value pair is added to the map.
665     * If the field is already present and it has the same value as that specified, no action occurs.
666     * If the field is already present and it has a different value to that specified, then
667     * an exception is thrown.
668     *
669     * @param field  the field to add, not null
670     * @param value  the value to add, not null
671     * @throws java.time.DateTimeException if the field is already present with a different value
672     */
673    void addFieldValue(Map<TemporalField, Long> fieldValues, ChronoField field, long value) {
674        Long old = fieldValues.get(field);  // check first for better error message
675        if (old != null && old.longValue() != value) {
676            throw new DateTimeException("Conflict found: " + field + " " + old + " differs from " + field + " " + value);
677        }
678        fieldValues.put(field, value);
679    }
680
681    //-----------------------------------------------------------------------
682    /**
683     * Compares this chronology to another chronology.
684     * <p>
685     * The comparison order first by the chronology ID string, then by any
686     * additional information specific to the subclass.
687     * It is "consistent with equals", as defined by {@link Comparable}.
688     *
689     * @implSpec
690     * This implementation compares the chronology ID.
691     * Subclasses must compare any additional state that they store.
692     *
693     * @param other  the other chronology to compare to, not null
694     * @return the comparator value, negative if less, positive if greater
695     */
696    @Override
697    public int compareTo(Chronology other) {
698        return getId().compareTo(other.getId());
699    }
700
701    /**
702     * Checks if this chronology is equal to another chronology.
703     * <p>
704     * The comparison is based on the entire state of the object.
705     *
706     * @implSpec
707     * This implementation checks the type and calls
708     * {@link #compareTo(java.time.chrono.Chronology)}.
709     *
710     * @param obj  the object to check, null returns false
711     * @return true if this is equal to the other chronology
712     */
713    @Override
714    public boolean equals(Object obj) {
715        if (this == obj) {
716           return true;
717        }
718        if (obj instanceof AbstractChronology) {
719            return compareTo((AbstractChronology) obj) == 0;
720        }
721        return false;
722    }
723
724    /**
725     * A hash code for this chronology.
726     * <p>
727     * The hash code should be based on the entire state of the object.
728     *
729     * @implSpec
730     * This implementation is based on the chronology ID and class.
731     * Subclasses should add any additional state that they store.
732     *
733     * @return a suitable hash code
734     */
735    @Override
736    public int hashCode() {
737        return getClass().hashCode() ^ getId().hashCode();
738    }
739
740    //-----------------------------------------------------------------------
741    /**
742     * Outputs this chronology as a {@code String}, using the chronology ID.
743     *
744     * @return a string representation of this chronology, not null
745     */
746    @Override
747    public String toString() {
748        return getId();
749    }
750
751    //-----------------------------------------------------------------------
752    /**
753     * Writes the Chronology using a
754     * <a href="../../../serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
755     * <pre>
756     *  out.writeByte(1);  // identifies this as a Chronology
757     *  out.writeUTF(getId());
758     * </pre>
759     *
760     * @return the instance of {@code Ser}, not null
761     */
762    Object writeReplace() {
763        return new Ser(Ser.CHRONO_TYPE, this);
764    }
765
766    /**
767     * Defend against malicious streams.
768     *
769     * @param s the stream to read
770     * @throws java.io.InvalidObjectException always
771     */
772    private void readObject(ObjectInputStream s) throws ObjectStreamException {
773        throw new InvalidObjectException("Deserialization via serialization delegate");
774    }
775
776    void writeExternal(DataOutput out) throws IOException {
777        out.writeUTF(getId());
778    }
779
780    static Chronology readExternal(DataInput in) throws IOException {
781        String id = in.readUTF();
782        return Chronology.of(id);
783    }
784
785}
786