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