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 * 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.ObjectStreamException;
72 import java.io.Serializable;
73 import java.time.DateTimeException;
74 import java.time.LocalDate;
75 import java.time.temporal.ChronoField;
76 import java.time.temporal.TemporalField;
77 import java.time.temporal.UnsupportedTemporalTypeException;
78 import java.time.temporal.ValueRange;
79 import java.util.Arrays;
80 import java.util.Objects;
81
82 import sun.util.calendar.CalendarDate;
83
84 /**
85 * An era in the Japanese Imperial calendar system.
86 * <p>
87 * This class defines the valid eras for the Japanese chronology.
88 * Japan introduced the Gregorian calendar starting with Meiji 6.
89 * Only Meiji and later eras are supported;
90 * dates before Meiji 6, January 1 are not supported.
91 *
92 * @implSpec
93 * This class is immutable and thread-safe.
94 *
95 * @since 1.8
96 */
97 public final class JapaneseEra
98 implements Era, Serializable {
99
100 // The offset value to 0-based index from the era value.
101 // i.e., getValue() + ERA_OFFSET == 0-based index
102 static final int ERA_OFFSET = 2;
103
104 static final sun.util.calendar.Era[] ERA_CONFIG;
105
106 /**
107 * The singleton instance for the 'Meiji' era (1868-09-08 - 1912-07-29)
108 * which has the value -1.
109 */
110 public static final JapaneseEra MEIJI = new JapaneseEra(-1, LocalDate.of(1868, 9, 8));
111 /**
112 * The singleton instance for the 'Taisho' era (1912-07-30 - 1926-12-24)
113 * which has the value 0.
114 */
115 public static final JapaneseEra TAISHO = new JapaneseEra(0, LocalDate.of(1912, 7, 30));
116 /**
117 * The singleton instance for the 'Showa' era (1926-12-25 - 1989-01-07)
118 * which has the value 1.
119 */
120 public static final JapaneseEra SHOWA = new JapaneseEra(1, LocalDate.of(1926, 12, 25));
121 /**
122 * The singleton instance for the 'Heisei' era (1989-01-08 - current)
123 * which has the value 2.
124 */
125 public static final JapaneseEra HEISEI = new JapaneseEra(2, LocalDate.of(1989, 1, 8));
126
127 // the number of defined JapaneseEra constants.
128 // There could be an extra era defined in its configuration.
129 private static final int N_ERA_CONSTANTS = HEISEI.getValue() + ERA_OFFSET + 1;
130
131 /**
132 * Serialization version.
133 */
134 private static final long serialVersionUID = 1466499369062886794L;
135
136 // array for the singleton JapaneseEra instances
137 private static final JapaneseEra[] KNOWN_ERAS;
138
139 static {
140 ERA_CONFIG = JapaneseChronology.JCAL.getEras();
141
142 KNOWN_ERAS = new JapaneseEra[ERA_CONFIG.length];
143 KNOWN_ERAS[0] = MEIJI;
144 KNOWN_ERAS[1] = TAISHO;
145 KNOWN_ERAS[2] = SHOWA;
146 KNOWN_ERAS[3] = HEISEI;
147 for (int i = N_ERA_CONSTANTS; i < ERA_CONFIG.length; i++) {
148 CalendarDate date = ERA_CONFIG[i].getSinceDate();
149 LocalDate isoDate = LocalDate.of(date.getYear(), date.getMonth(), date.getDayOfMonth());
150 KNOWN_ERAS[i] = new JapaneseEra(i - ERA_OFFSET, isoDate);
151 }
152 };
153
154 /**
155 * The era value.
156 * @serial
157 */
158 private final int eraValue;
159
160 // the first day of the era
161 private final transient LocalDate since;
162
163 /**
164 * Creates an instance.
165 *
166 * @param eraValue the era value, validated
167 * @param since the date representing the first date of the era, validated not null
168 */
169 private JapaneseEra(int eraValue, LocalDate since) {
170 this.eraValue = eraValue;
171 this.since = since;
172 }
173
174 /**
175 * Returns the singleton {@code JapaneseEra} corresponding to this object.
176 * It's possible that this version of {@code JapaneseEra} doesn't support the latest era value.
177 * In that case, this method throws an {@code ObjectStreamException}.
178 *
179 * @return the singleton {@code JapaneseEra} for this object
180 * @throws ObjectStreamException if the deserialized object has any unknown numeric era value.
181 */
182 private Object readResolve() throws ObjectStreamException {
183 try {
184 return of(eraValue);
185 } catch (DateTimeException e) {
186 InvalidObjectException ex = new InvalidObjectException("Invalid era");
187 ex.initCause(e);
188 throw ex;
189 }
190 }
191
192 //-----------------------------------------------------------------------
193 /**
194 * Returns the Sun private Era instance corresponding to this {@code JapaneseEra}.
195 *
196 * @return the Sun private Era instance for this {@code JapaneseEra}.
197 */
198 sun.util.calendar.Era getPrivateEra() {
199 return ERA_CONFIG[ordinal(eraValue)];
200 }
201
202 //-----------------------------------------------------------------------
203 /**
204 * Obtains an instance of {@code JapaneseEra} from an {@code int} value.
205 * <p>
206 * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1
207 * Later era is numbered 2 ({@link #HEISEI}). Earlier eras are numbered 0 ({@link #TAISHO}),
208 * -1 ({@link #MEIJI}), only Meiji and later eras are supported.
209 *
210 * @param japaneseEra the era to represent
211 * @return the {@code JapaneseEra} singleton, not null
212 * @throws DateTimeException if the value is invalid
213 */
214 public static JapaneseEra of(int japaneseEra) {
215 if (japaneseEra < MEIJI.eraValue || japaneseEra > HEISEI.eraValue) {
216 throw new DateTimeException("Invalid era: " + japaneseEra);
217 }
218 return KNOWN_ERAS[ordinal(japaneseEra)];
219 }
220
221 /**
222 * Returns the {@code JapaneseEra} with the name.
223 * <p>
224 * The string must match exactly the name of the era.
225 * (Extraneous whitespace characters are not permitted.)
226 *
227 * @param japaneseEra the japaneseEra name; non-null
228 * @return the {@code JapaneseEra} singleton, never null
229 * @throws IllegalArgumentException if there is not JapaneseEra with the specified name
230 */
231 public static JapaneseEra valueOf(String japaneseEra) {
232 Objects.requireNonNull(japaneseEra, "japaneseEra");
233 for (JapaneseEra era : KNOWN_ERAS) {
234 if (era.getName().equals(japaneseEra)) {
235 return era;
236 }
237 }
238 throw new IllegalArgumentException("japaneseEra is invalid");
239 }
240
241 /**
242 * Returns an array of JapaneseEras.
243 * <p>
244 * This method may be used to iterate over the JapaneseEras as follows:
245 * <pre>
246 * for (JapaneseEra c : JapaneseEra.values())
247 * System.out.println(c);
248 * </pre>
249 *
250 * @return an array of JapaneseEras
251 */
252 public static JapaneseEra[] values() {
253 return Arrays.copyOf(KNOWN_ERAS, KNOWN_ERAS.length);
254 }
255
256 //-----------------------------------------------------------------------
257 /**
258 * Obtains an instance of {@code JapaneseEra} from a date.
259 *
260 * @param date the date, not null
261 * @return the Era singleton, never null
262 */
263 static JapaneseEra from(LocalDate date) {
264 if (date.isBefore(MEIJI_6_ISODATE)) {
265 throw new DateTimeException("JapaneseDate before Meiji 6 are not supported");
266 }
267 for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
268 JapaneseEra era = KNOWN_ERAS[i];
269 if (date.compareTo(era.since) >= 0) {
270 return era;
271 }
272 }
273 return null;
274 }
275
276 static JapaneseEra toJapaneseEra(sun.util.calendar.Era privateEra) {
277 for (int i = ERA_CONFIG.length - 1; i >= 0; i--) {
278 if (ERA_CONFIG[i].equals(privateEra)) {
279 return KNOWN_ERAS[i];
280 }
281 }
282 return null;
283 }
284
285 static sun.util.calendar.Era privateEraFrom(LocalDate isoDate) {
286 for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
287 JapaneseEra era = KNOWN_ERAS[i];
288 if (isoDate.compareTo(era.since) >= 0) {
289 return ERA_CONFIG[i];
290 }
291 }
292 return null;
293 }
294
295 /**
296 * Returns the index into the arrays from the Era value.
297 * the eraValue is a valid Era number, -1..2.
298 *
299 * @param eraValue the era value to convert to the index
300 * @return the index of the current Era
301 */
302 private static int ordinal(int eraValue) {
303 return eraValue + ERA_OFFSET - 1;
304 }
305
306 //-----------------------------------------------------------------------
307 /**
308 * Gets the numeric era {@code int} value.
309 * <p>
310 * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1.
311 * Later eras are numbered from 2 ({@link #HEISEI}).
312 * Earlier eras are numbered 0 ({@link #TAISHO}), -1 ({@link #MEIJI})).
313 *
314 * @return the era value
315 */
316 @Override
317 public int getValue() {
318 return eraValue;
319 }
320
321 //-----------------------------------------------------------------------
322 /**
323 * Gets the range of valid values for the specified field.
324 * <p>
325 * The range object expresses the minimum and maximum valid values for a field.
326 * This era is used to enhance the accuracy of the returned range.
327 * If it is not possible to return the range, because the field is not supported
328 * or for some other reason, an exception is thrown.
329 * <p>
330 * If the field is a {@link ChronoField} then the query is implemented here.
331 * The {@code ERA} field returns the range.
332 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
333 * <p>
334 * If the field is not a {@code ChronoField}, then the result of this method
335 * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
336 * passing {@code this} as the argument.
337 * Whether the range can be obtained is determined by the field.
338 * <p>
339 * The range of valid Japanese eras can change over time due to the nature
340 * of the Japanese calendar system.
341 *
342 * @param field the field to query the range for, not null
343 * @return the range of valid values for the field, not null
344 * @throws DateTimeException if the range for the field cannot be obtained
345 * @throws UnsupportedTemporalTypeException if the unit is not supported
346 */
347 @Override // override as super would return range from 0 to 1
348 public ValueRange range(TemporalField field) {
349 if (field == ERA) {
350 return JapaneseChronology.INSTANCE.range(ERA);
351 }
352 return Era.super.range(field);
353 }
354
355 //-----------------------------------------------------------------------
356 String getAbbreviation() {
357 int index = ordinal(getValue());
358 if (index == 0) {
359 return "";
360 }
361 return ERA_CONFIG[index].getAbbreviation();
362 }
363
364 String getName() {
365 return ERA_CONFIG[ordinal(getValue())].getName();
366 }
367
368 @Override
369 public String toString() {
370 return getName();
371 }
372
373 //-----------------------------------------------------------------------
374 private Object writeReplace() {
375 return new Ser(Ser.JAPANESE_ERA_TYPE, this);
376 }
377
378 void writeExternal(DataOutput out) throws IOException {
379 out.writeByte(this.getValue());
380 }
381
382 static JapaneseEra readExternal(DataInput in) throws IOException {
383 byte eraValue = in.readByte();
384 return JapaneseEra.of(eraValue);
385 }
386
387 }