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 * Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
28 *
29 * All rights reserved.
30 *
31 * Redistribution and use in source and binary forms, with or without
32 * modification, are permitted provided that the following conditions are met:
33 *
34 * * Redistributions of source code must retain the above copyright notice,
35 * this list of conditions and the following disclaimer.
36 *
37 * * Redistributions in binary form must reproduce the above copyright notice,
38 * this list of conditions and the following disclaimer in the documentation
39 * and/or other materials provided with the distribution.
40 *
41 * * Neither the name of JSR-310 nor the names of its contributors
42 * may be used to endorse or promote products derived from this software
43 * without specific prior written permission.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
46 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
47 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
48 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
49 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
50 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
51 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
52 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
53 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
54 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
55 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
56 */
57 package java.time.calendar;
58
59 import java.io.DataInput;
60 import java.io.DataOutput;
61 import java.io.IOException;
62 import java.io.InvalidObjectException;
63 import java.io.ObjectStreamException;
64 import java.io.Serializable;
65 import java.time.DateTimeException;
66 import java.time.LocalDate;
67 import java.time.temporal.Era;
68 import java.util.Arrays;
69
70 import sun.util.calendar.CalendarDate;
71
72 /**
73 * An era in the Japanese Imperial calendar system.
74 * <p>
75 * This class defines the valid eras for the Japanese chronology.
76 * Only Meiji (1868-09-08 - 1912-07-29) and later eras are supported.
77 * Japan introduced the Gregorian calendar since Meiji 6. The dates
78 * between Meiji 1 - 5 are not historically correct.
79 * The older eras are recognized as Seireki (Western calendar) era,
80 * and the year of era of Seireki is proleptic Gregorian year.
81 * (The Julian to Gregorian transition is not supported.)
82 *
83 * <h3>Specification for implementors</h3>
84 * This class is immutable and thread-safe.
85 *
86 * @since 1.8
87 */
88 final class JapaneseEra
89 implements Era<JapaneseChrono>, Serializable {
90
91 // The offset value to 0-based index from the era value.
92 // i.e., getValue() + ERA_OFFSET == 0-based index; except that -999 is mapped to zero
93 static final int ERA_OFFSET = 2;
94
95 static final sun.util.calendar.Era[] ERA_CONFIG;
96
97 /**
98 * The singleton instance for the before Meiji era ( - 1868-09-07)
99 * which has the value -999.
100 */
101 public static final JapaneseEra SEIREKI = new JapaneseEra(-999, LocalDate.MIN);
102 /**
103 * The singleton instance for the 'Meiji' era (1868-09-08 - 1912-07-29)
104 * which has the value -1.
105 */
106 public static final JapaneseEra MEIJI = new JapaneseEra(-1, LocalDate.of(1868, 9, 8));
107 /**
108 * The singleton instance for the 'Taisho' era (1912-07-30 - 1926-12-24)
109 * which has the value 0.
110 */
111 public static final JapaneseEra TAISHO = new JapaneseEra(0, LocalDate.of(1912, 7, 30));
112 /**
113 * The singleton instance for the 'Showa' era (1926-12-25 - 1989-01-07)
114 * which has the value 1.
115 */
116 public static final JapaneseEra SHOWA = new JapaneseEra(1, LocalDate.of(1926, 12, 25));
117 /**
118 * The singleton instance for the 'Heisei' era (1989-01-08 - current)
119 * which has the value 2.
120 */
121 public static final JapaneseEra HEISEI = new JapaneseEra(2, LocalDate.of(1989, 1, 8));
122
123 // the number of defined JapaneseEra constants.
124 // There could be an extra era defined in its configuration.
125 private static final int N_ERA_CONSTANTS = HEISEI.getValue() + ERA_OFFSET + 1;
126
127 /**
128 * Serialization version.
129 */
130 private static final long serialVersionUID = 1466499369062886794L;
131
132 // array for the singleton JapaneseEra instances
133 private static final JapaneseEra[] KNOWN_ERAS;
134
135 static {
136 sun.util.calendar.Era[] sunEras = JapaneseChrono.JCAL.getEras();
137 ERA_CONFIG = new sun.util.calendar.Era[sunEras.length + 1];
138 for (int i = 1; i < ERA_CONFIG.length; i++) {
139 ERA_CONFIG[i] = sunEras[i - 1];
140 }
141 KNOWN_ERAS = new JapaneseEra[ERA_CONFIG.length];
142 KNOWN_ERAS[0] = SEIREKI;
143 KNOWN_ERAS[1] = MEIJI;
144 KNOWN_ERAS[2] = TAISHO;
145 KNOWN_ERAS[3] = SHOWA;
146 KNOWN_ERAS[4] = 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 * SEIREKI doesn't have its corresponding one.
196 *
197 * @return the Sun private Era instance for this {@code JapaneseEra},
198 * or null for SEIREKI.
199 */
200 sun.util.calendar.Era getPrivateEra() {
201 return ERA_CONFIG[ordinal(eraValue)];
202 }
203
204 //-----------------------------------------------------------------------
205 /**
206 * Obtains an instance of {@code JapaneseEra} from a value.
207 * <p>
208 * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1
209 * Later era is numbered 2 ({@link #HEISEI}). Earlier eras are numbered 0 ({@link #TAISHO}),
210 * -1 ({@link #MEIJI}), only Meiji and later eras are supported. The prior to Meiji,
211 * {@link #SEIREKI} is used.
212 *
213 * @param japaneseEra the era to represent
214 * @return the {@code JapaneseEra} singleton, never null
215 * @throws DateTimeException if {@code japaneseEra} is invalid
216 */
217 public static JapaneseEra of(int japaneseEra) {
218 if (japaneseEra != SEIREKI.eraValue &&
219 (japaneseEra < MEIJI.eraValue || japaneseEra > HEISEI.eraValue)) {
220 throw new DateTimeException("japaneseEra is invalid");
221 }
222 return KNOWN_ERAS[ordinal(japaneseEra)];
223 }
224
225 /**
226 * Returns an array of JapaneseEras.
227 * @return an array of JapaneseEras
228 */
229 static JapaneseEra[] values() {
230 return Arrays.copyOf(KNOWN_ERAS, KNOWN_ERAS.length);
231 }
232
233 //-----------------------------------------------------------------------
234 /**
235 * Obtains an instance of {@code JapaneseEra} from a date.
236 *
237 * @param date the date, not null
238 * @return the Era singleton, never null
239 */
240 static JapaneseEra from(LocalDate date) {
241 for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
242 JapaneseEra era = KNOWN_ERAS[i];
243 if (date.compareTo(era.since) >= 0) {
244 return era;
245 }
246 }
247 return SEIREKI;
248 }
249
250 static JapaneseEra toJapaneseEra(sun.util.calendar.Era privateEra) {
251 for (int i = ERA_CONFIG.length - 1; i > 0; i--) {
252 if (ERA_CONFIG[i].equals(privateEra)) {
253 return KNOWN_ERAS[i];
254 }
255 }
256 return SEIREKI;
257 }
258
259 static sun.util.calendar.Era privateEraFrom(LocalDate isoDate) {
260 for (int i = KNOWN_ERAS.length - 1; i > 0; i--) {
261 JapaneseEra era = KNOWN_ERAS[i];
262 if (isoDate.compareTo(era.since) >= 0) {
263 return ERA_CONFIG[i];
264 }
265 }
266 return null;
267 }
268
269 /**
270 * Returns the index into the arrays from the Era value.
271 * the eraValue is a valid Era number, -999, -1..2.
272 * @param eravalue the era value to convert to the index
273 * @return the index of the current Era
274 */
275 private static int ordinal(int eravalue) {
276 return (eravalue == SEIREKI.eraValue) ? 0 : eravalue + ERA_OFFSET;
277 }
278
279 //-----------------------------------------------------------------------
280 /**
281 * Returns the numeric value of this {@code JapaneseEra}.
282 * <p>
283 * The {@link #SHOWA} era that contains 1970-01-01 (ISO calendar system) has the value 1.
284 * Later eras are numbered from 2 ({@link #HEISEI}).
285 * Earlier eras are numbered 0 ({@link #TAISHO}), -1 ({@link #MEIJI}), and -999 ({@link #SEIREKI}).
286 *
287 * @return the era value
288 */
289 @Override
290 public int getValue() {
291 return eraValue;
292 }
293
294 @Override
295 public JapaneseChrono getChrono() {
296 return JapaneseChrono.INSTANCE;
297 }
298
299 //-----------------------------------------------------------------------
300 String getAbbreviation() {
301 int index = ordinal(getValue());
302 if (index == 0) {
303 return "";
304 }
305 return ERA_CONFIG[index].getAbbreviation();
306 }
307
308 String getName() {
309 int index = ordinal(getValue());
310 if (index == 0) {
311 return "Seireki";
312 }
313 return ERA_CONFIG[index].getName();
314 }
315
316 @Override
317 public String toString() {
318 return getName();
319 }
320
321 //-----------------------------------------------------------------------
322 private Object writeReplace() {
323 return new Ser(Ser.JAPANESE_ERA_TYPE, this);
324 }
325
326 void writeExternal(DataOutput out) throws IOException {
327 out.writeByte(this.getValue());
328 }
329
330 static JapaneseEra readExternal(DataInput in) throws IOException {
331 byte eraValue = in.readByte();
332 return JapaneseEra.of(eraValue);
333 }
334
335 }