1 /*
2 * Copyright (c) 2012, 2016, 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
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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.TextStyle;
77 import java.time.temporal.ChronoField;
78 import java.time.temporal.TemporalField;
79 import java.time.temporal.UnsupportedTemporalTypeException;
80 import java.time.temporal.ValueRange;
81 import java.util.Arrays;
82 import java.util.Locale;
83 import java.util.Objects;
84
85 import sun.util.calendar.CalendarDate;
86
87 /**
88 * An era in the Japanese Imperial calendar system.
89 * <p>
90 * This class defines the valid eras for the Japanese chronology.
91 * Japan introduced the Gregorian calendar starting with Meiji 6.
92 * Only Meiji and later eras are supported;
93 * dates before Meiji 6, January 1 are not supported.
94 *
95 * @implSpec
96 * This class is immutable and thread-safe.
97 *
98 * @since 1.8
99 */
100 public final class JapaneseEra
101 implements Era, Serializable {
102
103 // The offset value to 0-based index from the era value.
104 // i.e., getValue() + ERA_OFFSET == 0-based index
105 static final int ERA_OFFSET = 2;
106
107 static final sun.util.calendar.Era[] ERA_CONFIG;
108
109 /**
110 * The singleton instance for the 'Meiji' era (1868-01-01 - 1912-07-29)
111 * which has the value -1.
112 */
113 public static final JapaneseEra MEIJI = new JapaneseEra(-1, LocalDate.of(1868, 1, 1));
114 /**
115 * The singleton instance for the 'Taisho' era (1912-07-30 - 1926-12-24)
116 * which has the value 0.
117 */
118 public static final JapaneseEra TAISHO = new JapaneseEra(0, LocalDate.of(1912, 7, 30));
119 /**
120 * The singleton instance for the 'Showa' era (1926-12-25 - 1989-01-07)
121 * which has the value 1.
122 */
123 public static final JapaneseEra SHOWA = new JapaneseEra(1, LocalDate.of(1926, 12, 25));
124 /**
125 * The singleton instance for the 'Heisei' era (1989-01-08 - current)
126 * which has the value 2.
127 */
128 public static final JapaneseEra HEISEI = new JapaneseEra(2, LocalDate.of(1989, 1, 8));
129
130 // The number of predefined JapaneseEra constants.
131 // There may be a supplemental era defined by the property.
132 private static final int N_ERA_CONSTANTS = HEISEI.getValue() + ERA_OFFSET;
133
134 /**
135 * Serialization version.
136 */
137 private static final long serialVersionUID = 1466499369062886794L;
138
139 // array for the singleton JapaneseEra instances
140 private static final JapaneseEra[] KNOWN_ERAS;
141
142 static {
143 ERA_CONFIG = JapaneseChronology.JCAL.getEras();
144
145 KNOWN_ERAS = new JapaneseEra[ERA_CONFIG.length];
146 KNOWN_ERAS[0] = MEIJI;
147 KNOWN_ERAS[1] = TAISHO;
148 KNOWN_ERAS[2] = SHOWA;
149 KNOWN_ERAS[3] = HEISEI;
150 for (int i = N_ERA_CONSTANTS; i < ERA_CONFIG.length; i++) {
151 CalendarDate date = ERA_CONFIG[i].getSinceDate();
152 LocalDate isoDate = LocalDate.of(date.getYear(), date.getMonth(), date.getDayOfMonth());
153 KNOWN_ERAS[i] = new JapaneseEra(i - ERA_OFFSET + 1, isoDate);
154 }
155 };
156
157 /**
158 * The era value.
159 * @serial
160 */
161 private final transient int eraValue;
162
163 // the first day of the era
164 private final transient LocalDate since;
165
166 /**
167 * Creates an instance.
168 *
169 * @param eraValue the era value, validated
170 * @param since the date representing the first date of the era, validated not null
171 */
172 private JapaneseEra(int eraValue, LocalDate since) {
173 this.eraValue = eraValue;
174 this.since = since;
175 }
176
177 //-----------------------------------------------------------------------
178 /**
179 * Returns the Sun private Era instance corresponding to this {@code JapaneseEra}.
180 *
181 * @return the Sun private Era instance for this {@code JapaneseEra}.
182 */
183 sun.util.calendar.Era getPrivateEra() {
184 return ERA_CONFIG[ordinal(eraValue)];
185 }
186
187 //-----------------------------------------------------------------------
188 /**
189 * Obtains an instance of {@code JapaneseEra} from an {@code int} value.
190 * <p>
191 * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1
192 * Later era is numbered 2 ({@link #HEISEI}). Earlier eras are numbered 0 ({@link #TAISHO}),
193 * -1 ({@link #MEIJI}), only Meiji and later eras are supported.
194 *
195 * @param japaneseEra the era to represent
196 * @return the {@code JapaneseEra} singleton, not null
197 * @throws DateTimeException if the value is invalid
198 */
199 public static JapaneseEra of(int japaneseEra) {
200 int i = ordinal(japaneseEra);
201 if (i < 0 || i >= KNOWN_ERAS.length) {
202 throw new DateTimeException("Invalid era: " + japaneseEra);
203 }
204 return KNOWN_ERAS[i];
205 }
206
207 /**
208 * Returns the {@code JapaneseEra} with the name.
209 * <p>
210 * The string must match exactly the name of the era.
211 * (Extraneous whitespace characters are not permitted.)
212 *
213 * @param japaneseEra the japaneseEra name; non-null
214 * @return the {@code JapaneseEra} singleton, never null
215 * @throws IllegalArgumentException if there is not JapaneseEra with the specified name
216 */
217 public static JapaneseEra valueOf(String japaneseEra) {
218 Objects.requireNonNull(japaneseEra, "japaneseEra");
219 for (JapaneseEra era : KNOWN_ERAS) {
220 if (era.getName().equals(japaneseEra)) {
221 return era;
222 }
223 }
224 throw new IllegalArgumentException("japaneseEra is invalid");
225 }
226
227 /**
228 * Returns an array of JapaneseEras.
229 * <p>
230 * This method may be used to iterate over the JapaneseEras as follows:
231 * <pre>
232 * for (JapaneseEra c : JapaneseEra.values())
233 * System.out.println(c);
234 * </pre>
235 *
236 * @return an array of JapaneseEras
237 */
238 public static JapaneseEra[] values() {
239 return Arrays.copyOf(KNOWN_ERAS, KNOWN_ERAS.length);
240 }
241
242 /**
243 * Gets the textual representation of this era.
244 * <p>
245 * This returns the textual name used to identify the era,
246 * suitable for presentation to the user.
247 * The parameters control the style of the returned text and the locale.
248 * <p>
249 * If no textual mapping is found then the {@link #getValue() numeric value}
250 * is returned.
251 *
252 * @param style the style of the text required, not null
253 * @param locale the locale to use, not null
254 * @return the text value of the era, not null
255 * @since 9
256 */
257 @Override
258 public String getDisplayName(TextStyle style, Locale locale) {
259 // If this JapaneseEra is a supplemental one, obtain the name from
260 // the era definition.
261 if (getValue() > N_ERA_CONSTANTS - ERA_OFFSET) {
262 Objects.requireNonNull(locale, "locale");
263 return style.asNormal() == TextStyle.NARROW ? getAbbreviation() : getName();
264 }
265 return Era.super.getDisplayName(style, locale);
266 }
267
268 //-----------------------------------------------------------------------
269 /**
270 * Obtains an instance of {@code JapaneseEra} from a date.
271 *
272 * @param date the date, not null
273 * @return the Era singleton, never null
274 */
275 static JapaneseEra from(LocalDate date) {
276 if (date.isBefore(MEIJI_6_ISODATE)) {
277 throw new DateTimeException("JapaneseDate before Meiji 6 are not supported");
278 }
279 for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
280 JapaneseEra era = KNOWN_ERAS[i];
281 if (date.compareTo(era.since) >= 0) {
282 return era;
283 }
284 }
285 return null;
286 }
287
288 static JapaneseEra toJapaneseEra(sun.util.calendar.Era privateEra) {
289 for (int i = ERA_CONFIG.length - 1; i >= 0; i--) {
290 if (ERA_CONFIG[i].equals(privateEra)) {
291 return KNOWN_ERAS[i];
292 }
293 }
294 return null;
295 }
296
297 static sun.util.calendar.Era privateEraFrom(LocalDate isoDate) {
298 for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
299 JapaneseEra era = KNOWN_ERAS[i];
300 if (isoDate.compareTo(era.since) >= 0) {
301 return ERA_CONFIG[i];
302 }
303 }
304 return null;
305 }
306
307 /**
308 * Returns the index into the arrays from the Era value.
309 * the eraValue is a valid Era number, -1..2.
310 *
311 * @param eraValue the era value to convert to the index
312 * @return the index of the current Era
313 */
314 private static int ordinal(int eraValue) {
315 return eraValue + ERA_OFFSET - 1;
316 }
317
318 //-----------------------------------------------------------------------
319 /**
320 * Gets the numeric era {@code int} value.
321 * <p>
322 * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1.
323 * Later eras are numbered from 2 ({@link #HEISEI}).
324 * Earlier eras are numbered 0 ({@link #TAISHO}), -1 ({@link #MEIJI})).
325 *
326 * @return the era value
327 */
328 @Override
329 public int getValue() {
330 return eraValue;
331 }
332
333 //-----------------------------------------------------------------------
334 /**
335 * Gets the range of valid values for the specified field.
336 * <p>
337 * The range object expresses the minimum and maximum valid values for a field.
338 * This era is used to enhance the accuracy of the returned range.
339 * If it is not possible to return the range, because the field is not supported
340 * or for some other reason, an exception is thrown.
341 * <p>
342 * If the field is a {@link ChronoField} then the query is implemented here.
343 * The {@code ERA} field returns the range.
344 * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
345 * <p>
346 * If the field is not a {@code ChronoField}, then the result of this method
347 * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
348 * passing {@code this} as the argument.
349 * Whether the range can be obtained is determined by the field.
350 * <p>
351 * The range of valid Japanese eras can change over time due to the nature
352 * of the Japanese calendar system.
353 *
354 * @param field the field to query the range for, not null
355 * @return the range of valid values for the field, not null
356 * @throws DateTimeException if the range for the field cannot be obtained
357 * @throws UnsupportedTemporalTypeException if the unit is not supported
358 */
359 @Override // override as super would return range from 0 to 1
360 public ValueRange range(TemporalField field) {
361 if (field == ERA) {
362 return JapaneseChronology.INSTANCE.range(ERA);
363 }
364 return Era.super.range(field);
365 }
366
367 //-----------------------------------------------------------------------
368 String getAbbreviation() {
369 return ERA_CONFIG[ordinal(getValue())].getAbbreviation();
370 }
371
372 String getName() {
373 return ERA_CONFIG[ordinal(getValue())].getName();
374 }
375
376 @Override
377 public String toString() {
378 return getName();
379 }
380
381 //-----------------------------------------------------------------------
382 /**
383 * Defend against malicious streams.
384 *
385 * @param s the stream to read
386 * @throws InvalidObjectException always
387 */
388 private void readObject(ObjectInputStream s) throws InvalidObjectException {
389 throw new InvalidObjectException("Deserialization via serialization delegate");
390 }
391
392 //-----------------------------------------------------------------------
393 /**
394 * Writes the object using a
395 * <a href="../../../serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
396 * @serialData
397 * <pre>
398 * out.writeByte(5); // identifies a JapaneseEra
399 * out.writeInt(getValue());
400 * </pre>
401 *
402 * @return the instance of {@code Ser}, not null
403 */
404 private Object writeReplace() {
405 return new Ser(Ser.JAPANESE_ERA_TYPE, this);
406 }
407
408 void writeExternal(DataOutput out) throws IOException {
409 out.writeByte(this.getValue());
410 }
411
412 static JapaneseEra readExternal(DataInput in) throws IOException {
413 byte eraValue = in.readByte();
414 return JapaneseEra.of(eraValue);
415 }
416
417 }