1 /*
2 * Copyright (c) 2012, 2018, 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 * 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 */
62 package java.time.chrono;
63
64 import static java.time.chrono.JapaneseDate.MEIJI_6_ISODATE;
65 import static java.time.temporal.ChronoField.ERA;
66
67 import java.io.DataInput;
68 import java.io.DataOutput;
69 import java.io.IOException;
70 import java.io.InvalidObjectException;
71 import java.io.ObjectInputStream;
72 import java.io.ObjectStreamException;
73 import java.io.Serializable;
74 import java.time.DateTimeException;
75 import java.time.LocalDate;
76 import java.time.format.DateTimeFormatterBuilder;
77 import java.time.format.TextStyle;
78 import java.time.temporal.ChronoField;
79 import java.time.temporal.TemporalField;
80 import java.time.temporal.UnsupportedTemporalTypeException;
81 import java.time.temporal.ValueRange;
82 import java.util.Arrays;
83 import java.util.Locale;
84 import java.util.Objects;
85
86 import sun.util.calendar.CalendarDate;
87
88 /**
89 * An era in the Japanese Imperial calendar system.
90 * <p>
91 * This class defines the valid eras for the Japanese chronology.
92 * Japan introduced the Gregorian calendar starting with Meiji 6.
93 * Only Meiji and later eras are supported;
94 * dates before Meiji 6, January 1 are not supported.
95 * The number of the valid eras may increase, as new eras may be
96 * defined by the Japanese government. Once an era is defined,
97 * subsequent versions of this class will add a singleton instance
98 * for it. The defined era is expected to have a consecutive integer
99 * associated with it.
100 *
101 * @implSpec
102 * This class is immutable and thread-safe.
103 *
104 * @since 1.8
105 */
106 public final class JapaneseEra
107 implements Era, Serializable {
108
109 // The offset value to 0-based index from the era value.
110 // i.e., getValue() + ERA_OFFSET == 0-based index
111 static final int ERA_OFFSET = 2;
112
113 static final sun.util.calendar.Era[] ERA_CONFIG;
114
115 /**
116 * The singleton instance for the 'Meiji' era (1868-01-01 - 1912-07-29)
117 * which has the value -1.
118 */
119 public static final JapaneseEra MEIJI = new JapaneseEra(-1, LocalDate.of(1868, 1, 1));
120 /**
121 * The singleton instance for the 'Taisho' era (1912-07-30 - 1926-12-24)
122 * which has the value 0.
123 */
124 public static final JapaneseEra TAISHO = new JapaneseEra(0, LocalDate.of(1912, 7, 30));
125 /**
126 * The singleton instance for the 'Showa' era (1926-12-25 - 1989-01-07)
127 * which has the value 1.
128 */
129 public static final JapaneseEra SHOWA = new JapaneseEra(1, LocalDate.of(1926, 12, 25));
130 /**
131 * The singleton instance for the 'Heisei' era (1989-01-08 - 2019-04-30)
132 * which has the value 2.
133 */
134 public static final JapaneseEra HEISEI = new JapaneseEra(2, LocalDate.of(1989, 1, 8));
135 /**
136 * The singleton instance for the 'NewEra' era (2019-05-01 - current)
137 * which has the value 3.
138 */
139 private static final JapaneseEra NEWERA = new JapaneseEra(3, LocalDate.of(2019, 5, 1));
140
141 // The number of predefined JapaneseEra constants.
142 // There may be a supplemental era defined by the property.
143 private static final int N_ERA_CONSTANTS = NEWERA.getValue() + ERA_OFFSET;
144
145 /**
146 * Serialization version.
147 */
148 private static final long serialVersionUID = 1466499369062886794L;
149
150 // array for the singleton JapaneseEra instances
151 private static final JapaneseEra[] KNOWN_ERAS;
152
153 static {
154 ERA_CONFIG = JapaneseChronology.JCAL.getEras();
155
156 KNOWN_ERAS = new JapaneseEra[ERA_CONFIG.length];
157 KNOWN_ERAS[0] = MEIJI;
158 KNOWN_ERAS[1] = TAISHO;
159 KNOWN_ERAS[2] = SHOWA;
160 KNOWN_ERAS[3] = HEISEI;
161 KNOWN_ERAS[4] = NEWERA;
162 for (int i = N_ERA_CONSTANTS; i < ERA_CONFIG.length; i++) {
163 CalendarDate date = ERA_CONFIG[i].getSinceDate();
164 LocalDate isoDate = LocalDate.of(date.getYear(), date.getMonth(), date.getDayOfMonth());
165 KNOWN_ERAS[i] = new JapaneseEra(i - ERA_OFFSET + 1, isoDate);
166 }
167 };
168
169 /**
170 * The era value.
171 * @serial
172 */
173 private final transient int eraValue;
174
175 // the first day of the era
176 private final transient LocalDate since;
177
178 /**
179 * Creates an instance.
180 *
181 * @param eraValue the era value, validated
182 * @param since the date representing the first date of the era, validated not null
183 */
184 private JapaneseEra(int eraValue, LocalDate since) {
185 this.eraValue = eraValue;
186 this.since = since;
187 }
188
189 //-----------------------------------------------------------------------
190 /**
191 * Returns the Sun private Era instance corresponding to this {@code JapaneseEra}.
192 *
193 * @return the Sun private Era instance for this {@code JapaneseEra}.
194 */
195 sun.util.calendar.Era getPrivateEra() {
196 return ERA_CONFIG[ordinal(eraValue)];
197 }
198
199 //-----------------------------------------------------------------------
200 /**
201 * Obtains an instance of {@code JapaneseEra} from an {@code int} value.
202 * <p>
203 * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1.
204 * Later era is numbered 2 ({@link #HEISEI}). Earlier eras are numbered 0 ({@link #TAISHO}),
205 * -1 ({@link #MEIJI}), only Meiji and later eras are supported.
206 * <p>
207 * In addition to the known era singletons, values for additional
208 * eras may be defined. Those values are the {@link Era#getValue()}
209 * of corresponding eras from the {@link #values()} method.
210 *
211 * @param japaneseEra the era to represent
212 * @return the {@code JapaneseEra} singleton, not null
213 * @throws DateTimeException if the value is invalid
214 */
215 public static JapaneseEra of(int japaneseEra) {
216 int i = ordinal(japaneseEra);
217 if (i < 0 || i >= KNOWN_ERAS.length) {
218 throw new DateTimeException("Invalid era: " + japaneseEra);
219 }
220 return KNOWN_ERAS[i];
221 }
222
223 /**
224 * Returns the {@code JapaneseEra} with the name.
225 * <p>
226 * The string must match exactly the name of the era.
227 * (Extraneous whitespace characters are not permitted.)
228 * <p>
229 * Valid era names are the names of eras returned from {@link #values()}.
230 *
231 * @param japaneseEra the japaneseEra name; non-null
232 * @return the {@code JapaneseEra} singleton, never null
233 * @throws IllegalArgumentException if there is not JapaneseEra with the specified name
234 */
235 public static JapaneseEra valueOf(String japaneseEra) {
236 Objects.requireNonNull(japaneseEra, "japaneseEra");
237 for (JapaneseEra era : KNOWN_ERAS) {
238 if (era.getName().equals(japaneseEra)) {
239 return era;
240 }
241 }
242 throw new IllegalArgumentException("japaneseEra is invalid");
243 }
244
245 /**
246 * Returns an array of JapaneseEras. The array may contain eras defined
247 * by the Japanese government beyond the known era singletons.
248 *
249 * <p>
250 * This method may be used to iterate over the JapaneseEras as follows:
251 * <pre>
252 * for (JapaneseEra c : JapaneseEra.values())
253 * System.out.println(c);
254 * </pre>
255 *
256 * @return an array of JapaneseEras
257 */
258 public static JapaneseEra[] values() {
259 return Arrays.copyOf(KNOWN_ERAS, KNOWN_ERAS.length);
260 }
261
262 /**
263 * {@inheritDoc}
264 *
265 * @param style {@inheritDoc}
266 * @param locale {@inheritDoc}
267 */
268 @Override
269 public String getDisplayName(TextStyle style, Locale locale) {
270 // If this JapaneseEra is a supplemental one, obtain the name from
271 // the era definition.
272 if (getValue() > N_ERA_CONSTANTS - ERA_OFFSET) {
273 Objects.requireNonNull(locale, "locale");
274 return style.asNormal() == TextStyle.NARROW ? getAbbreviation() : getName();
275 }
276
277 return new DateTimeFormatterBuilder()
278 .appendText(ERA, style)
279 .toFormatter(locale)
280 .withChronology(JapaneseChronology.INSTANCE)
281 .format(this == MEIJI ? MEIJI_6_ISODATE : since);
282 }
283
284 //-----------------------------------------------------------------------
285 /**
286 * Obtains an instance of {@code JapaneseEra} from a date.
287 *
288 * @param date the date, not null
289 * @return the Era singleton, never null
290 */
291 static JapaneseEra from(LocalDate date) {
292 if (date.isBefore(MEIJI_6_ISODATE)) {
293 throw new DateTimeException("JapaneseDate before Meiji 6 are not supported");
294 }
295 for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
296 JapaneseEra era = KNOWN_ERAS[i];
297 if (date.compareTo(era.since) >= 0) {
298 return era;
299 }
300 }
301 return null;
302 }
303
304 static JapaneseEra toJapaneseEra(sun.util.calendar.Era privateEra) {
305 for (int i = ERA_CONFIG.length - 1; i >= 0; i--) {
306 if (ERA_CONFIG[i].equals(privateEra)) {
307 return KNOWN_ERAS[i];
308 }
309 }
310 return null;
311 }
312
313 static sun.util.calendar.Era privateEraFrom(LocalDate isoDate) {
314 for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
315 JapaneseEra era = KNOWN_ERAS[i];
316 if (isoDate.compareTo(era.since) >= 0) {
317 return ERA_CONFIG[i];
318 }
319 }
320 return null;
321 }
322
323 /**
324 * Returns the index into the arrays from the Era value.
325 * the eraValue is a valid Era number, -1..2.
326 *
327 * @param eraValue the era value to convert to the index
328 * @return the index of the current Era
329 */
330 private static int ordinal(int eraValue) {
331 return eraValue + ERA_OFFSET - 1;
332 }
333
334 //-----------------------------------------------------------------------
335 /**
336 * Gets the numeric era {@code int} value.
337 * <p>
338 * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1.
339 * Later eras are numbered from 2 ({@link #HEISEI}).
340 * Earlier eras are numbered 0 ({@link #TAISHO}), -1 ({@link #MEIJI})).
341 *
342 * @return the era value
343 */
344 @Override
345 public int getValue() {
346 return eraValue;
347 }
348
349 //-----------------------------------------------------------------------
350 /**
351 * Gets the range of valid values for the specified field.
352 * <p>
353 * The range object expresses the minimum and maximum valid values for a field.
354 * This era is used to enhance the accuracy of the returned range.
355 * If it is not possible to return the range, because the field is not supported
356 * or for some other reason, an exception is thrown.
357 * <p>
358 * If the field is a {@link ChronoField} then the query is implemented here.
359 * The {@code ERA} field returns the range.
360 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
361 * <p>
362 * If the field is not a {@code ChronoField}, then the result of this method
363 * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
364 * passing {@code this} as the argument.
365 * Whether the range can be obtained is determined by the field.
366 * <p>
367 * The range of valid Japanese eras can change over time due to the nature
368 * of the Japanese calendar system.
369 *
370 * @param field the field to query the range for, not null
371 * @return the range of valid values for the field, not null
372 * @throws DateTimeException if the range for the field cannot be obtained
373 * @throws UnsupportedTemporalTypeException if the unit is not supported
374 */
375 @Override // override as super would return range from 0 to 1
376 public ValueRange range(TemporalField field) {
377 if (field == ERA) {
378 return JapaneseChronology.INSTANCE.range(ERA);
379 }
380 return Era.super.range(field);
381 }
382
383 //-----------------------------------------------------------------------
384 String getAbbreviation() {
385 return ERA_CONFIG[ordinal(getValue())].getAbbreviation();
386 }
387
388 String getName() {
389 return ERA_CONFIG[ordinal(getValue())].getName();
390 }
391
392 @Override
393 public String toString() {
394 return getName();
395 }
396
397 //-----------------------------------------------------------------------
398 /**
399 * Defend against malicious streams.
400 *
401 * @param s the stream to read
402 * @throws InvalidObjectException always
403 */
404 private void readObject(ObjectInputStream s) throws InvalidObjectException {
405 throw new InvalidObjectException("Deserialization via serialization delegate");
406 }
407
408 //-----------------------------------------------------------------------
409 /**
410 * Writes the object using a
411 * <a href="{@docRoot}/serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
412 * @serialData
413 * <pre>
414 * out.writeByte(5); // identifies a JapaneseEra
415 * out.writeInt(getValue());
416 * </pre>
417 *
418 * @return the instance of {@code Ser}, not null
419 */
420 private Object writeReplace() {
421 return new Ser(Ser.JAPANESE_ERA_TYPE, this);
422 }
423
424 void writeExternal(DataOutput out) throws IOException {
425 out.writeByte(this.getValue());
426 }
427
428 static JapaneseEra readExternal(DataInput in) throws IOException {
429 byte eraValue = in.readByte();
430 return JapaneseEra.of(eraValue);
431 }
432
433 }