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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
23  * questions.
24  */
25 
26 /*
27  * Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
28  *
29  * All rights reserved.
30  *
31  * Redistribution and use in source and binary forms, with or without
32  * modification, are permitted provided that the following conditions are met:
33  *
34  *  * Redistributions of source code must retain the above copyright notice,
35  *    this list of conditions and the following disclaimer.
36  *
37  *  * Redistributions in binary form must reproduce the above copyright notice,
38  *    this list of conditions and the following disclaimer in the documentation
39  *    and/or other materials provided with the distribution.
40  *
41  *  * Neither the name of JSR-310 nor the names of its contributors
42  *    may be used to endorse or promote products derived from this software
43  *    without specific prior written permission.
44  *
45  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
46  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
47  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
48  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
49  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
50  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
51  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
52  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
53  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
54  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
55  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
56  */
57 package java.time.chrono;
58 
59 import static java.time.temporal.ChronoField.DAY_OF_MONTH;
60 import static java.time.temporal.ChronoField.DAY_OF_YEAR;
61 import static java.time.temporal.ChronoField.ERA;
62 import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
63 import static java.time.temporal.ChronoField.YEAR;
64 import static java.time.temporal.ChronoField.YEAR_OF_ERA;
65 import static java.time.temporal.ChronoUnit.DAYS;
66 import static java.time.temporal.ChronoUnit.MONTHS;
67 
68 import java.io.InvalidObjectException;
69 import java.io.ObjectInputStream;
70 import java.io.Serializable;
71 import java.time.Clock;
72 import java.time.DateTimeException;
73 import java.time.Instant;
74 import java.time.LocalDate;
75 import java.time.Year;
76 import java.time.ZoneId;
77 import java.time.format.ResolverStyle;
78 import java.time.temporal.ChronoField;
79 import java.time.temporal.TemporalAccessor;
80 import java.time.temporal.TemporalAdjusters;
81 import java.time.temporal.TemporalField;
82 import java.time.temporal.UnsupportedTemporalTypeException;
83 import java.time.temporal.ValueRange;
84 import java.util.Calendar;
85 import java.util.List;
86 import java.util.Locale;
87 import java.util.Map;
88 import java.util.TimeZone;
89 
90 import sun.util.calendar.CalendarSystem;
91 import sun.util.calendar.LocalGregorianCalendar;
92 
93 /**
94  * The Japanese Imperial calendar system.
95  * <p>
96  * This chronology defines the rules of the Japanese Imperial calendar system.
97  * This calendar system is primarily used in Japan.
98  * The Japanese Imperial calendar system is the same as the ISO calendar system
99  * apart from the era-based year numbering.
100  * <p>
101  * Japan introduced the Gregorian calendar starting with Meiji 6.
102  * Only Meiji and later eras are supported;
103  * dates before Meiji 6, January 1 are not supported.
104  * <p>
105  * The supported {@code ChronoField} instances are:
106  * <ul>
107  * <li>{@code DAY_OF_WEEK}
108  * <li>{@code DAY_OF_MONTH}
109  * <li>{@code DAY_OF_YEAR}
110  * <li>{@code EPOCH_DAY}
111  * <li>{@code MONTH_OF_YEAR}
112  * <li>{@code PROLEPTIC_MONTH}
113  * <li>{@code YEAR_OF_ERA}
114  * <li>{@code YEAR}
115  * <li>{@code ERA}
116  * </ul>
117  *
118  * @implSpec
119  * This class is immutable and thread-safe.
120  *
121  * @since 1.8
122  */
123 public final class JapaneseChronology extends AbstractChronology implements Serializable {
124 
125     static final LocalGregorianCalendar JCAL =
126         (LocalGregorianCalendar) CalendarSystem.forName("japanese");
127 
128     // Android-changed: don't use locale to create japanese imperial calendar, as it's not generally
129     // supported on Android. Use Calendar.getJapaneseImperialInstance() instead. See .createCalendar
130     // Locale for creating a JapaneseImpericalCalendar.
131     private static final Locale LOCALE = Locale.forLanguageTag("ja-JP-u-ca-japanese");
132 
createCalendar()133     static Calendar createCalendar() {
134         return Calendar.getJapaneseImperialInstance(TimeZone.getDefault(), LOCALE);
135     }
136 
137     /**
138      * Singleton instance for Japanese chronology.
139      */
140     public static final JapaneseChronology INSTANCE = new JapaneseChronology();
141 
142     /**
143      * Serialization version.
144      */
145     private static final long serialVersionUID = 459996390165777884L;
146 
147     //-----------------------------------------------------------------------
148     /**
149      * Restricted constructor.
150      */
JapaneseChronology()151     private JapaneseChronology() {
152     }
153 
154     //-----------------------------------------------------------------------
155     /**
156      * Gets the ID of the chronology - 'Japanese'.
157      * <p>
158      * The ID uniquely identifies the {@code Chronology}.
159      * It can be used to lookup the {@code Chronology} using {@link Chronology#of(String)}.
160      *
161      * @return the chronology ID - 'Japanese'
162      * @see #getCalendarType()
163      */
164     @Override
getId()165     public String getId() {
166         return "Japanese";
167     }
168 
169     /**
170      * Gets the calendar type of the underlying calendar system - 'japanese'.
171      * <p>
172      * The calendar type is an identifier defined by the
173      * <em>Unicode Locale Data Markup Language (LDML)</em> specification.
174      * It can be used to lookup the {@code Chronology} using {@link Chronology#of(String)}.
175      * It can also be used as part of a locale, accessible via
176      * {@link Locale#getUnicodeLocaleType(String)} with the key 'ca'.
177      *
178      * @return the calendar system type - 'japanese'
179      * @see #getId()
180      */
181     @Override
getCalendarType()182     public String getCalendarType() {
183         return "japanese";
184     }
185 
186     //-----------------------------------------------------------------------
187     /**
188      * Obtains a local date in Japanese calendar system from the
189      * era, year-of-era, month-of-year and day-of-month fields.
190      * <p>
191      * The Japanese month and day-of-month are the same as those in the
192      * ISO calendar system. They are not reset when the era changes.
193      * For example:
194      * <pre>
195      *  6th Jan Showa 64 = ISO 1989-01-06
196      *  7th Jan Showa 64 = ISO 1989-01-07
197      *  8th Jan Heisei 1 = ISO 1989-01-08
198      *  9th Jan Heisei 1 = ISO 1989-01-09
199      * </pre>
200      *
201      * @param era  the Japanese era, not null
202      * @param yearOfEra  the year-of-era
203      * @param month  the month-of-year
204      * @param dayOfMonth  the day-of-month
205      * @return the Japanese local date, not null
206      * @throws DateTimeException if unable to create the date
207      * @throws ClassCastException if the {@code era} is not a {@code JapaneseEra}
208      */
209     @Override
date(Era era, int yearOfEra, int month, int dayOfMonth)210     public JapaneseDate date(Era era, int yearOfEra, int month, int dayOfMonth) {
211         if (era instanceof JapaneseEra == false) {
212             throw new ClassCastException("Era must be JapaneseEra");
213         }
214         return JapaneseDate.of((JapaneseEra) era, yearOfEra, month, dayOfMonth);
215     }
216 
217     /**
218      * Obtains a local date in Japanese calendar system from the
219      * proleptic-year, month-of-year and day-of-month fields.
220      * <p>
221      * The Japanese proleptic year, month and day-of-month are the same as those
222      * in the ISO calendar system. They are not reset when the era changes.
223      *
224      * @param prolepticYear  the proleptic-year
225      * @param month  the month-of-year
226      * @param dayOfMonth  the day-of-month
227      * @return the Japanese local date, not null
228      * @throws DateTimeException if unable to create the date
229      */
230     @Override
date(int prolepticYear, int month, int dayOfMonth)231     public JapaneseDate date(int prolepticYear, int month, int dayOfMonth) {
232         return new JapaneseDate(LocalDate.of(prolepticYear, month, dayOfMonth));
233     }
234 
235     /**
236      * Obtains a local date in Japanese calendar system from the
237      * era, year-of-era and day-of-year fields.
238      * <p>
239      * The day-of-year in this factory is expressed relative to the start of the year-of-era.
240      * This definition changes the normal meaning of day-of-year only in those years
241      * where the year-of-era is reset to one due to a change in the era.
242      * For example:
243      * <pre>
244      *  6th Jan Showa 64 = day-of-year 6
245      *  7th Jan Showa 64 = day-of-year 7
246      *  8th Jan Heisei 1 = day-of-year 1
247      *  9th Jan Heisei 1 = day-of-year 2
248      * </pre>
249      *
250      * @param era  the Japanese era, not null
251      * @param yearOfEra  the year-of-era
252      * @param dayOfYear  the day-of-year
253      * @return the Japanese local date, not null
254      * @throws DateTimeException if unable to create the date
255      * @throws ClassCastException if the {@code era} is not a {@code JapaneseEra}
256      */
257     @Override
dateYearDay(Era era, int yearOfEra, int dayOfYear)258     public JapaneseDate dateYearDay(Era era, int yearOfEra, int dayOfYear) {
259         return JapaneseDate.ofYearDay((JapaneseEra) era, yearOfEra, dayOfYear);
260     }
261 
262     /**
263      * Obtains a local date in Japanese calendar system from the
264      * proleptic-year and day-of-year fields.
265      * <p>
266      * The day-of-year in this factory is expressed relative to the start of the proleptic year.
267      * The Japanese proleptic year and day-of-year are the same as those in the ISO calendar system.
268      * They are not reset when the era changes.
269      *
270      * @param prolepticYear  the proleptic-year
271      * @param dayOfYear  the day-of-year
272      * @return the Japanese local date, not null
273      * @throws DateTimeException if unable to create the date
274      */
275     @Override
dateYearDay(int prolepticYear, int dayOfYear)276     public JapaneseDate dateYearDay(int prolepticYear, int dayOfYear) {
277         return new JapaneseDate(LocalDate.ofYearDay(prolepticYear, dayOfYear));
278     }
279 
280     /**
281      * Obtains a local date in the Japanese calendar system from the epoch-day.
282      *
283      * @param epochDay  the epoch day
284      * @return the Japanese local date, not null
285      * @throws DateTimeException if unable to create the date
286      */
287     @Override  // override with covariant return type
dateEpochDay(long epochDay)288     public JapaneseDate dateEpochDay(long epochDay) {
289         return new JapaneseDate(LocalDate.ofEpochDay(epochDay));
290     }
291 
292     @Override
dateNow()293     public JapaneseDate dateNow() {
294         return dateNow(Clock.systemDefaultZone());
295     }
296 
297     @Override
dateNow(ZoneId zone)298     public JapaneseDate dateNow(ZoneId zone) {
299         return dateNow(Clock.system(zone));
300     }
301 
302     @Override
dateNow(Clock clock)303     public JapaneseDate dateNow(Clock clock) {
304         return date(LocalDate.now(clock));
305     }
306 
307     @Override
date(TemporalAccessor temporal)308     public JapaneseDate date(TemporalAccessor temporal) {
309         if (temporal instanceof JapaneseDate) {
310             return (JapaneseDate) temporal;
311         }
312         return new JapaneseDate(LocalDate.from(temporal));
313     }
314 
315     @Override
316     @SuppressWarnings("unchecked")
localDateTime(TemporalAccessor temporal)317     public ChronoLocalDateTime<JapaneseDate> localDateTime(TemporalAccessor temporal) {
318         return (ChronoLocalDateTime<JapaneseDate>)super.localDateTime(temporal);
319     }
320 
321     @Override
322     @SuppressWarnings("unchecked")
zonedDateTime(TemporalAccessor temporal)323     public ChronoZonedDateTime<JapaneseDate> zonedDateTime(TemporalAccessor temporal) {
324         return (ChronoZonedDateTime<JapaneseDate>)super.zonedDateTime(temporal);
325     }
326 
327     @Override
328     @SuppressWarnings("unchecked")
zonedDateTime(Instant instant, ZoneId zone)329     public ChronoZonedDateTime<JapaneseDate> zonedDateTime(Instant instant, ZoneId zone) {
330         return (ChronoZonedDateTime<JapaneseDate>)super.zonedDateTime(instant, zone);
331     }
332 
333     //-----------------------------------------------------------------------
334     /**
335      * Checks if the specified year is a leap year.
336      * <p>
337      * Japanese calendar leap years occur exactly in line with ISO leap years.
338      * This method does not validate the year passed in, and only has a
339      * well-defined result for years in the supported range.
340      *
341      * @param prolepticYear  the proleptic-year to check, not validated for range
342      * @return true if the year is a leap year
343      */
344     @Override
isLeapYear(long prolepticYear)345     public boolean isLeapYear(long prolepticYear) {
346         return IsoChronology.INSTANCE.isLeapYear(prolepticYear);
347     }
348 
349     @Override
prolepticYear(Era era, int yearOfEra)350     public int prolepticYear(Era era, int yearOfEra) {
351         if (era instanceof JapaneseEra == false) {
352             throw new ClassCastException("Era must be JapaneseEra");
353         }
354 
355         JapaneseEra jera = (JapaneseEra) era;
356         int gregorianYear = jera.getPrivateEra().getSinceDate().getYear() + yearOfEra - 1;
357         if (yearOfEra == 1) {
358             return gregorianYear;
359         }
360         if (gregorianYear >= Year.MIN_VALUE && gregorianYear <= Year.MAX_VALUE) {
361             LocalGregorianCalendar.Date jdate = JCAL.newCalendarDate(null);
362             jdate.setEra(jera.getPrivateEra()).setDate(yearOfEra, 1, 1);
363             if (JapaneseChronology.JCAL.validate(jdate)) {
364                 return gregorianYear;
365             }
366         }
367         throw new DateTimeException("Invalid yearOfEra value");
368     }
369 
370     // Android-changed: Integrate OpenJDK support for Japanese Era Reiwa.
371     /**
372      * Returns the calendar system era object from the given numeric value.
373      *
374      * The numeric values supported by this method are the same as the
375      * numeric values supported by {@link JapaneseEra#of(int)}.
376      *
377      * @param eraValue  the era value
378      * @return the Japanese {@code Era} for the given numeric era value
379      * @throws DateTimeException if {@code eraValue} is invalid
380      */
381     @Override
eraOf(int eraValue)382     public JapaneseEra eraOf(int eraValue) {
383         return JapaneseEra.of(eraValue);
384     }
385 
386     @Override
eras()387     public List<Era> eras() {
388         return List.of(JapaneseEra.values());
389     }
390 
getCurrentEra()391     JapaneseEra getCurrentEra() {
392         // Assume that the last JapaneseEra is the current one.
393         JapaneseEra[] eras = JapaneseEra.values();
394         return eras[eras.length - 1];
395     }
396 
397     //-----------------------------------------------------------------------
398     @Override
range(ChronoField field)399     public ValueRange range(ChronoField field) {
400         switch (field) {
401             case ALIGNED_DAY_OF_WEEK_IN_MONTH:
402             case ALIGNED_DAY_OF_WEEK_IN_YEAR:
403             case ALIGNED_WEEK_OF_MONTH:
404             case ALIGNED_WEEK_OF_YEAR:
405                 throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
406             case YEAR_OF_ERA: {
407                 // Android-changed: use #createCalendar() to create calendar.
408                 Calendar jcal = createCalendar();
409                 int startYear = getCurrentEra().getPrivateEra().getSinceDate().getYear();
410                 return ValueRange.of(1, jcal.getGreatestMinimum(Calendar.YEAR),
411                         jcal.getLeastMaximum(Calendar.YEAR) + 1, // +1 due to the different definitions
412                         Year.MAX_VALUE - startYear);
413             }
414             case DAY_OF_YEAR: {
415                 // Android-changed: use #createCalendar() to create calendar.
416                 Calendar jcal = createCalendar();
417                 int fieldIndex = Calendar.DAY_OF_YEAR;
418                 return ValueRange.of(jcal.getMinimum(fieldIndex), jcal.getGreatestMinimum(fieldIndex),
419                         jcal.getLeastMaximum(fieldIndex), jcal.getMaximum(fieldIndex));
420             }
421             case YEAR:
422                 return ValueRange.of(JapaneseDate.MEIJI_6_ISODATE.getYear(), Year.MAX_VALUE);
423             case ERA:
424                 return ValueRange.of(JapaneseEra.MEIJI.getValue(), getCurrentEra().getValue());
425             default:
426                 return field.range();
427         }
428     }
429 
430     //-----------------------------------------------------------------------
431     @Override  // override for return type
resolveDate(Map <TemporalField, Long> fieldValues, ResolverStyle resolverStyle)432     public JapaneseDate resolveDate(Map <TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
433         return (JapaneseDate) super.resolveDate(fieldValues, resolverStyle);
434     }
435 
436     @Override  // override for special Japanese behavior
resolveYearOfEra(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle)437     ChronoLocalDate resolveYearOfEra(Map<TemporalField, Long> fieldValues, ResolverStyle resolverStyle) {
438         // validate era and year-of-era
439         Long eraLong = fieldValues.get(ERA);
440         JapaneseEra era = null;
441         if (eraLong != null) {
442             era = eraOf(range(ERA).checkValidIntValue(eraLong, ERA));  // always validated
443         }
444         Long yoeLong = fieldValues.get(YEAR_OF_ERA);
445         int yoe = 0;
446         if (yoeLong != null) {
447             yoe = range(YEAR_OF_ERA).checkValidIntValue(yoeLong, YEAR_OF_ERA);  // always validated
448         }
449         // if only year-of-era and no year then invent era unless strict
450         if (era == null && yoeLong != null && fieldValues.containsKey(YEAR) == false && resolverStyle != ResolverStyle.STRICT) {
451             era = JapaneseEra.values()[JapaneseEra.values().length - 1];
452         }
453         // if both present, then try to create date
454         if (yoeLong != null && era != null) {
455             if (fieldValues.containsKey(MONTH_OF_YEAR)) {
456                 if (fieldValues.containsKey(DAY_OF_MONTH)) {
457                     return resolveYMD(era, yoe, fieldValues, resolverStyle);
458                 }
459             }
460             if (fieldValues.containsKey(DAY_OF_YEAR)) {
461                 return resolveYD(era, yoe, fieldValues, resolverStyle);
462             }
463         }
464         return null;
465     }
466 
prolepticYearLenient(JapaneseEra era, int yearOfEra)467     private int prolepticYearLenient(JapaneseEra era, int yearOfEra) {
468         return era.getPrivateEra().getSinceDate().getYear() + yearOfEra - 1;
469     }
470 
resolveYMD(JapaneseEra era, int yoe, Map<TemporalField,Long> fieldValues, ResolverStyle resolverStyle)471     private ChronoLocalDate resolveYMD(JapaneseEra era, int yoe, Map<TemporalField,Long> fieldValues, ResolverStyle resolverStyle) {
472         fieldValues.remove(ERA);
473         fieldValues.remove(YEAR_OF_ERA);
474         if (resolverStyle == ResolverStyle.LENIENT) {
475             int y = prolepticYearLenient(era, yoe);
476             long months = Math.subtractExact(fieldValues.remove(MONTH_OF_YEAR), 1);
477             long days = Math.subtractExact(fieldValues.remove(DAY_OF_MONTH), 1);
478             return date(y, 1, 1).plus(months, MONTHS).plus(days, DAYS);
479         }
480         int moy = range(MONTH_OF_YEAR).checkValidIntValue(fieldValues.remove(MONTH_OF_YEAR), MONTH_OF_YEAR);
481         int dom = range(DAY_OF_MONTH).checkValidIntValue(fieldValues.remove(DAY_OF_MONTH), DAY_OF_MONTH);
482         if (resolverStyle == ResolverStyle.SMART) {  // previous valid
483             if (yoe < 1) {
484                 throw new DateTimeException("Invalid YearOfEra: " + yoe);
485             }
486             int y = prolepticYearLenient(era, yoe);
487             JapaneseDate result;
488             try {
489                 result = date(y, moy, dom);
490             } catch (DateTimeException ex) {
491                 result = date(y, moy, 1).with(TemporalAdjusters.lastDayOfMonth());
492             }
493             // handle the era being changed
494             // only allow if the new date is in the same Jan-Dec as the era change
495             // determine by ensuring either original yoe or result yoe is 1
496             if (result.getEra() != era && result.get(YEAR_OF_ERA) > 1 && yoe > 1) {
497                 throw new DateTimeException("Invalid YearOfEra for Era: " + era + " " + yoe);
498             }
499             return result;
500         }
501         return date(era, yoe, moy, dom);
502     }
503 
resolveYD(JapaneseEra era, int yoe, Map <TemporalField,Long> fieldValues, ResolverStyle resolverStyle)504     private ChronoLocalDate resolveYD(JapaneseEra era, int yoe, Map <TemporalField,Long> fieldValues, ResolverStyle resolverStyle) {
505         fieldValues.remove(ERA);
506         fieldValues.remove(YEAR_OF_ERA);
507         if (resolverStyle == ResolverStyle.LENIENT) {
508             int y = prolepticYearLenient(era, yoe);
509             long days = Math.subtractExact(fieldValues.remove(DAY_OF_YEAR), 1);
510             return dateYearDay(y, 1).plus(days, DAYS);
511         }
512         int doy = range(DAY_OF_YEAR).checkValidIntValue(fieldValues.remove(DAY_OF_YEAR), DAY_OF_YEAR);
513         return dateYearDay(era, yoe, doy);  // smart is same as strict
514     }
515 
516     //-----------------------------------------------------------------------
517     /**
518      * Writes the Chronology using a
519      * <a href="../../../serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
520      * @serialData
521      * <pre>
522      *  out.writeByte(1);     // identifies a Chronology
523      *  out.writeUTF(getId());
524      * </pre>
525      *
526      * @return the instance of {@code Ser}, not null
527      */
528     @Override
writeReplace()529     Object writeReplace() {
530         return super.writeReplace();
531     }
532 
533     /**
534      * Defend against malicious streams.
535      *
536      * @param s the stream to read
537      * @throws InvalidObjectException always
538      */
readObject(ObjectInputStream s)539     private void readObject(ObjectInputStream s) throws InvalidObjectException {
540         throw new InvalidObjectException("Deserialization via serialization delegate");
541     }
542 }
543