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