1 /*
2 * Copyright (c) 2012, 2017, 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 */
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 *
96 * @implSpec
97 * This class is immutable and thread-safe.
98 *
99 * @since 1.8
100 */
101 public final class JapaneseEra
102 implements Era, Serializable {
103
104 // The offset value to 0-based index from the era value.
105 // i.e., getValue() + ERA_OFFSET == 0-based index
106 static final int ERA_OFFSET = 2;
107
108 static final sun.util.calendar.Era[] ERA_CONFIG;
109
110 /**
111 * The singleton instance for the 'Meiji' era (1868-01-01 - 1912-07-29)
112 * which has the value -1.
113 */
114 public static final JapaneseEra MEIJI = new JapaneseEra(-1, LocalDate.of(1868, 1, 1));
115 /**
116 * The singleton instance for the 'Taisho' era (1912-07-30 - 1926-12-24)
117 * which has the value 0.
118 */
119 public static final JapaneseEra TAISHO = new JapaneseEra(0, LocalDate.of(1912, 7, 30));
120 /**
121 * The singleton instance for the 'Showa' era (1926-12-25 - 1989-01-07)
122 * which has the value 1.
123 */
124 public static final JapaneseEra SHOWA = new JapaneseEra(1, LocalDate.of(1926, 12, 25));
125 /**
126 * The singleton instance for the 'Heisei' era (1989-01-08 - current)
127 * which has the value 2.
128 */
129 public static final JapaneseEra HEISEI = new JapaneseEra(2, LocalDate.of(1989, 1, 8));
130
131 // The number of predefined JapaneseEra constants.
132 // There may be a supplemental era defined by the property.
133 private static final int N_ERA_CONSTANTS = HEISEI.getValue() + ERA_OFFSET;
134
135 /**
136 * Serialization version.
137 */
138 private static final long serialVersionUID = 1466499369062886794L;
139
140 // array for the singleton JapaneseEra instances
141 private static final JapaneseEra[] KNOWN_ERAS;
142
143 static {
144 ERA_CONFIG = JapaneseChronology.JCAL.getEras();
145
146 KNOWN_ERAS = new JapaneseEra[ERA_CONFIG.length];
147 KNOWN_ERAS[0] = MEIJI;
148 KNOWN_ERAS[1] = TAISHO;
149 KNOWN_ERAS[2] = SHOWA;
150 KNOWN_ERAS[3] = HEISEI;
151 for (int i = N_ERA_CONSTANTS; i < ERA_CONFIG.length; i++) {
152 CalendarDate date = ERA_CONFIG[i].getSinceDate();
153 LocalDate isoDate = LocalDate.of(date.getYear(), date.getMonth(), date.getDayOfMonth());
154 KNOWN_ERAS[i] = new JapaneseEra(i - ERA_OFFSET + 1, isoDate);
155 }
156 };
157
158 /**
159 * The era value.
160 * @serial
161 */
162 private final transient int eraValue;
163
164 // the first day of the era
165 private final transient LocalDate since;
166
167 /**
168 * Creates an instance.
169 *
170 * @param eraValue the era value, validated
171 * @param since the date representing the first date of the era, validated not null
172 */
173 private JapaneseEra(int eraValue, LocalDate since) {
174 this.eraValue = eraValue;
175 this.since = since;
176 }
177
178 //-----------------------------------------------------------------------
179 /**
180 * Returns the Sun private Era instance corresponding to this {@code JapaneseEra}.
181 *
182 * @return the Sun private Era instance for this {@code JapaneseEra}.
183 */
184 sun.util.calendar.Era getPrivateEra() {
185 return ERA_CONFIG[ordinal(eraValue)];
186 }
187
188 //-----------------------------------------------------------------------
189 /**
190 * Obtains an instance of {@code JapaneseEra} from an {@code int} value.
191 * <p>
192 * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1
193 * Later era is numbered 2 ({@link #HEISEI}). Earlier eras are numbered 0 ({@link #TAISHO}),
194 * -1 ({@link #MEIJI}), only Meiji and later eras are supported.
195 *
196 * @param japaneseEra the era to represent
197 * @return the {@code JapaneseEra} singleton, not null
198 * @throws DateTimeException if the value is invalid
199 */
200 public static JapaneseEra of(int japaneseEra) {
201 int i = ordinal(japaneseEra);
202 if (i < 0 || i >= KNOWN_ERAS.length) {
203 throw new DateTimeException("Invalid era: " + japaneseEra);
204 }
205 return KNOWN_ERAS[i];
206 }
207
208 /**
209 * Returns the {@code JapaneseEra} with the name.
210 * <p>
211 * The string must match exactly the name of the era.
212 * (Extraneous whitespace characters are not permitted.)
213 *
214 * @param japaneseEra the japaneseEra name; non-null
215 * @return the {@code JapaneseEra} singleton, never null
216 * @throws IllegalArgumentException if there is not JapaneseEra with the specified name
217 */
218 public static JapaneseEra valueOf(String japaneseEra) {
219 Objects.requireNonNull(japaneseEra, "japaneseEra");
220 for (JapaneseEra era : KNOWN_ERAS) {
221 if (era.getName().equals(japaneseEra)) {
222 return era;
223 }
224 }
225 throw new IllegalArgumentException("japaneseEra is invalid");
226 }
227
228 /**
229 * Returns an array of JapaneseEras.
230 * <p>
231 * This method may be used to iterate over the JapaneseEras as follows:
232 * <pre>
233 * for (JapaneseEra c : JapaneseEra.values())
234 * System.out.println(c);
235 * </pre>
236 *
237 * @return an array of JapaneseEras
238 */
239 public static JapaneseEra[] values() {
240 return Arrays.copyOf(KNOWN_ERAS, KNOWN_ERAS.length);
241 }
242
243 /**
244 * {@inheritDoc}
245 *
246 * @param style {@inheritDoc}
247 * @param locale {@inheritDoc}
248 */
249 @Override
250 public String getDisplayName(TextStyle style, Locale locale) {
251 // If this JapaneseEra is a supplemental one, obtain the name from
252 // the era definition.
253 if (getValue() > N_ERA_CONSTANTS - ERA_OFFSET) {
254 Objects.requireNonNull(locale, "locale");
255 return style.asNormal() == TextStyle.NARROW ? getAbbreviation() : getName();
256 }
257
258 return new DateTimeFormatterBuilder()
259 .appendText(ERA, style)
260 .toFormatter(locale)
261 .withChronology(JapaneseChronology.INSTANCE)
262 .format(this == MEIJI ? MEIJI_6_ISODATE : since);
263 }
264
265 //-----------------------------------------------------------------------
266 /**
267 * Obtains an instance of {@code JapaneseEra} from a date.
268 *
269 * @param date the date, not null
270 * @return the Era singleton, never null
271 */
272 static JapaneseEra from(LocalDate date) {
273 if (date.isBefore(MEIJI_6_ISODATE)) {
274 throw new DateTimeException("JapaneseDate before Meiji 6 are not supported");
275 }
276 for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
277 JapaneseEra era = KNOWN_ERAS[i];
278 if (date.compareTo(era.since) >= 0) {
279 return era;
280 }
281 }
282 return null;
283 }
284
285 static JapaneseEra toJapaneseEra(sun.util.calendar.Era privateEra) {
286 for (int i = ERA_CONFIG.length - 1; i >= 0; i--) {
287 if (ERA_CONFIG[i].equals(privateEra)) {
288 return KNOWN_ERAS[i];
289 }
290 }
291 return null;
292 }
293
294 static sun.util.calendar.Era privateEraFrom(LocalDate isoDate) {
295 for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
296 JapaneseEra era = KNOWN_ERAS[i];
297 if (isoDate.compareTo(era.since) >= 0) {
298 return ERA_CONFIG[i];
299 }
300 }
301 return null;
302 }
303
304 /**
305 * Returns the index into the arrays from the Era value.
306 * the eraValue is a valid Era number, -1..2.
307 *
308 * @param eraValue the era value to convert to the index
309 * @return the index of the current Era
310 */
311 private static int ordinal(int eraValue) {
312 return eraValue + ERA_OFFSET - 1;
313 }
314
315 //-----------------------------------------------------------------------
316 /**
317 * Gets the numeric era {@code int} value.
318 * <p>
319 * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1.
320 * Later eras are numbered from 2 ({@link #HEISEI}).
321 * Earlier eras are numbered 0 ({@link #TAISHO}), -1 ({@link #MEIJI})).
322 *
323 * @return the era value
324 */
325 @Override
326 public int getValue() {
327 return eraValue;
328 }
329
330 //-----------------------------------------------------------------------
331 /**
332 * Gets the range of valid values for the specified field.
333 * <p>
334 * The range object expresses the minimum and maximum valid values for a field.
335 * This era is used to enhance the accuracy of the returned range.
336 * If it is not possible to return the range, because the field is not supported
337 * or for some other reason, an exception is thrown.
338 * <p>
339 * If the field is a {@link ChronoField} then the query is implemented here.
340 * The {@code ERA} field returns the range.
341 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
342 * <p>
343 * If the field is not a {@code ChronoField}, then the result of this method
344 * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
345 * passing {@code this} as the argument.
346 * Whether the range can be obtained is determined by the field.
347 * <p>
348 * The range of valid Japanese eras can change over time due to the nature
349 * of the Japanese calendar system.
350 *
351 * @param field the field to query the range for, not null
352 * @return the range of valid values for the field, not null
353 * @throws DateTimeException if the range for the field cannot be obtained
354 * @throws UnsupportedTemporalTypeException if the unit is not supported
355 */
356 @Override // override as super would return range from 0 to 1
357 public ValueRange range(TemporalField field) {
358 if (field == ERA) {
359 return JapaneseChronology.INSTANCE.range(ERA);
360 }
361 return Era.super.range(field);
362 }
363
364 //-----------------------------------------------------------------------
365 String getAbbreviation() {
366 return ERA_CONFIG[ordinal(getValue())].getAbbreviation();
367 }
368
369 String getName() {
370 return ERA_CONFIG[ordinal(getValue())].getName();
371 }
372
373 @Override
374 public String toString() {
375 return getName();
376 }
377
378 //-----------------------------------------------------------------------
379 /**
380 * Defend against malicious streams.
381 *
382 * @param s the stream to read
383 * @throws InvalidObjectException always
384 */
385 private void readObject(ObjectInputStream s) throws InvalidObjectException {
386 throw new InvalidObjectException("Deserialization via serialization delegate");
387 }
388
389 //-----------------------------------------------------------------------
390 /**
391 * Writes the object using a
392 * <a href="../../../serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
393 * @serialData
394 * <pre>
395 * out.writeByte(5); // identifies a JapaneseEra
396 * out.writeInt(getValue());
397 * </pre>
398 *
399 * @return the instance of {@code Ser}, not null
400 */
401 private Object writeReplace() {
402 return new Ser(Ser.JAPANESE_ERA_TYPE, this);
403 }
404
405 void writeExternal(DataOutput out) throws IOException {
406 out.writeByte(this.getValue());
407 }
408
409 static JapaneseEra readExternal(DataInput in) throws IOException {
410 byte eraValue = in.readByte();
411 return JapaneseEra.of(eraValue);
412 }
413
414 }